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[ { "answer_id": 85, "body": "<h3>20-20-20 Rule</h3>\n<p>Every 20 minutes of looking at the screen, look at something 20 feet away for 20 seconds. Also, try to blink a lot.</p>\n<h3>Adjusting settings</h3>\n<p>Using a larger font to read helps to reduce eye strain. Adjusting your brightness helps, usually brighter screens are better in brighter rooms, dimmer screens are better in dark rooms.</p>\n<p>Also, try to make your computer screen lower than your eyes; more of your eye is covered by your eyelid when you look down, so there will be more lubrication and you will subconsciously blink more.</p>\n<h3>Eating</h3>\n<p>Eat foods with vitamin A, which helps with the health of your eyes. See <a href=\"https://health.stackexchange.com/questions/79/do-carrots-actually-improve-eyesight\">this question</a> for more.</p>\n<hr />\n<p><a href=\"http://visianinfo.com/the-20-20-20-rule-preventing-digital-eye-strain/\" rel=\"noreferrer\">^{The 20-20-20 Rule: Preventing Digital Eye Strain}</a><br />\n_{<a href=\"http://onlinelibrary.wiley.com/doi/10.1111/j.1475-1313.2011.00834.x/full\" rel=\"noreferrer\">Computer vision syndrome: a review of ocular causes and potential treatments</a>}<br />\n_{<a href=\"http://commons.erau.edu/jaaer/vol24/iss2/5/?utm_source=commons.erau.edu%2Fjaaer%2Fvol24%2Fiss2%2F5&amp;utm_medium=PDF&amp;utm_campaign=PDFCoverPages\" rel=\"noreferrer\">Assessing Computer Vision Syndrome Risk for Pilots</a>}<br />\n_{<a href=\"http://www.mayoclinic.org/diseases-conditions/eyestrain/basics/prevention/con-20032649\" rel=\"noreferrer\">Eyestrain</a>}</p>\n", "score": 79 }, { "answer_id": 468, "body": "<p>There are some options you have to reduce eye strain.</p>\n\n<ul>\n<li><p>You can get an anti glare cover for your monitor</p></li>\n<li><p>You can also adjust lighting of your work area (not always possible) \nby lowering internal lighting and blocking external lighting.</p></li>\n<li><p>You can adjust the setting of your monitor to make the brightness<br>\nsimilar to your surroundings which will help with strain</p></li>\n<li><p>You can blink more often to keep your eyes from drying out You can \ntake breaks both by leaving your computer or by moving your eyes<br>\naround the room/desk and avoiding your computer every once in a<br>\nwhile.</p></li>\n<li><p>You can set up your desk to make sure printed material is in easy eye\nreach and lighted similarly</p></li>\n<li><p>You can look into getting specialized gaming/computer glasses which<br>\nare designed to reduce eye strain and fatigue</p></li>\n</ul>\n\n<p><a href=\"http://www.allaboutvision.com/cvs/irritated.htm\">http://www.allaboutvision.com/cvs/irritated.htm</a></p>\n", "score": 25 }, { "answer_id": 1104, "body": "<p>The primary risk is what is called Computer Vision Syndrome (<a href=\"http://www.webmd.com/eye-health/computer-vision-syndrome\">ref</a>, <a href=\"http://www.aoa.org/patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome?sso=y\">ref</a>, <a href=\"http://en.wikipedia.org/wiki/Computer_vision_syndrome\">ref</a>).</p>\n\n<p>The American Optometric Association (referenced above) recommends the following changes in viewing habits to alleviate symptoms:</p>\n\n<blockquote>\n <p>Some important factors in preventing or reducing the symptoms of CVS\n have to do with the computer and how it is used. This includes\n lighting conditions, chair comfort, location of reference materials,\n position of the monitor, and the use of rest breaks.</p>\n \n <ul>\n <li><strong>Location of computer screen</strong> - Most people find it more comfortable to\n view a computer when the eyes are looking downward. Optimally, the\n computer screen should be 15 to 20 degrees below eye level (about 4 or\n 5 inches) as measured from the center of the screen and 20 to 28\n inches from the eyes. </li>\n <li><strong>Reference materials</strong> - These materials should be\n located above the keyboard and below the monitor. If this is not\n possible, a document holder can be used beside the monitor. The goal\n is to position the documents so you do not need to move your head to\n look from the document to the screen.</li>\n <li><strong>Lighting</strong> - Position the computer\n screen to avoid glare, particularly from overhead lighting or windows.\n Use blinds or drapes on windows and replace the light bulbs in desk\n lamps with bulbs of lower wattage. </li>\n <li><strong>Anti-glare screens</strong> - If there is no\n way to minimize glare from light sources, consider using a screen\n glare filter. These filters decrease the amount of light reflected\n from the screen.</li>\n <li><strong>Seating position</strong> - Chairs should be comfortably\n padded and conform to the body. Chair height should be adjusted so\n your feet rest flat on the floor. If your chair has arms, they should\n be adjusted to provide arm support while you are typing. Your wrists\n shouldn't rest on the keyboard when typing.</li>\n <li><strong>Rest breaks</strong> - To prevent\n eyestrain, try to rest your eyes when using the computer for long\n periods. Rest your eyes for 15 minutes after two hours of continuous\n computer use. Also, for every 20 minutes of computer viewing, look\n into the distance for 20 seconds to allow your eyes a chance to\n refocus. </li>\n <li><strong>Blinking</strong> - To minimize your chances of developing dry eye\n when using a computer, make an effort to blink frequently. Blinking\n keeps the front surface of your eye moist.</li>\n </ul>\n \n <p>Regular eye examinations and proper viewing habits can help to prevent\n or reduce the development of the symptoms associated with Computer\n Vision Syndrome.</p>\n</blockquote>\n\n<p>Also, from WebMD:</p>\n\n<blockquote>\n <ul>\n <li><strong>Tweak your computer settings.</strong> You don't have to live with the factory-installed settings on your computer if you're uncomfortable. Adjust the brightness, contrast, and font size until you find the best settings for your vision.</li>\n </ul>\n</blockquote>\n\n<p>Gunnar glasses: Studies have shown <a href=\"http://en.wikipedia.org/wiki/Gunnar_Optiks\">some short term relief</a> but generally no evidence has yet surfaced to support benefits of these glasses for long term health.</p>\n", "score": 22 }, { "answer_id": 907, "body": "<p>You can also use <a href=\"https://justgetflux.com/\" rel=\"noreferrer\">f.lux</a>, it is a software that adjusts automatically and according to your location the brightness and contrast of your monitor. It lowers UV light during day, and lowers IR light during night.</p>\n", "score": 13 }, { "answer_id": 235, "body": "<p>The health of your eyesight when using computer it really depends what kind of screen you're using and many other factors (DNA, diet, etc.), but in general, modern monitors (such as <a href=\"http://en.wikipedia.org/wiki/Liquid_crystal_display\" rel=\"nofollow\">LCD</a>, <a href=\"http://en.wikipedia.org/wiki/LED-backlit_LCD_display\" rel=\"nofollow\">LED-backlit</a>, <a href=\"http://en.wikipedia.org/wiki/LED_display\" rel=\"nofollow\">white-LED</a>, <a href=\"http://en.wikipedia.org/wiki/OLED#Disadvantages\" rel=\"nofollow\">OLED</a>) does nothing to the health of your eyes, unless you're still using <a href=\"http://en.wikipedia.org/wiki/Cathode_ray_tube\" rel=\"nofollow\">CRT</a> monitor. The bigger issue is rather neck and back if you don't site properly.</p>\n\n<p>Remember, if you feel your eyes are not comfortable, you may adjust the brightness and contrast of your screen.</p>\n\n<p>If you're using computer for too long, it's completely normal that your eyes would be tired and it really depends on the person (professionals can spent 8-12 everyday for years and their eyesight is perfect, for other 1h is enough). </p>\n\n<p>In this case, you simply need a rest. It's usually advice to do short breaks and take a fresh air. You may also consider to train your eye muscles as a number of <a href=\"http://en.wikipedia.org/wiki/Ophthalmology\" rel=\"nofollow\">ophthalmologists</a> believe that an exercise programme based on something called the <a href=\"http://en.wikipedia.org/wiki/Bates_method\" rel=\"nofollow\">Bates Method</a> may keep eyes in better shape.</p>\n\n<p>See: <a href=\"http://www.independent.co.uk/life-style/can-you-really-train-your-eyes-to-see-better-1240390.html\" rel=\"nofollow\">Can you really train your eyes to see better?</a> where we can read:</p>\n\n<blockquote>\n <p>Some of the principles of the Bates Method are already accepted by mainstream eye care.</p>\n</blockquote>\n\n<hr>\n\n<p>More information about older monitors:</p>\n\n<p><strong><a href=\"http://en.wikipedia.org/wiki/Cathode_ray_tube\" rel=\"nofollow\">CRT</a></strong></p>\n\n<p>If you're using CRT most people experience mild discomfort unless the <a href=\"http://en.wikipedia.org/wiki/Refresh_rate\" rel=\"nofollow\">refresh rate</a> is set to 72 Hz or higher. A rate of 100 Hz is comfortable at almost any size. It's usually advice to have a screen protector. However CRT are long lost technologies and this doesn't apply anymore to LCD monitors. </p>\n", "score": 6 }, { "answer_id": 11235, "body": "<p><a href=\"https://en.wikipedia.org/wiki/The_Vision_Council\" rel=\"noreferrer\">The Vision Council</a>, which represents the manufacturers and suppliers of the optical industry, suggests the following tips to prevent and lessen digital eye strain:</p>\n\n<ul>\n<li>Adjust the brightness of your device. Consider changing your background color from bright white to cool gray.\nAttach a glare reduction filter to your computer screen.</li>\n<li>Frequently dust and wipe digital screens to help reduce glare.</li>\n<li>Adjust your screen so that it is directly in front of your face and slightly below eye level. Do not tilt a computer\nmonitor.</li>\n<li>Position yourself or your device so there is sufficient distance between your eyes and the screen.</li>\n<li>Lessen the amount of overhead and surrounding light that is competing with your device’s screen.</li>\n<li>When using a computer, first sit in your chair and extend your arm. Your palm should rest comfortably on the\nmonitor (as if you’re high-fiving the screen).</li>\n<li>Keep handheld devices a safe distance from your eyes and just below eye level.</li>\n<li>Increase text size to better define the content on your screen. Use the settings control to make adjustments that\nfeel comfortable to your eyes.</li>\n<li>Remind yourself to blink more often. Staring at a digital screen can affect the number of times you blink, causing\neyes to dry.</li>\n<li>Take a 20-20-20 break: Every 20 minutes, take a 20-second break and look at something 20 feet away.</li>\n<li>Parents should limit the amount of screen time for children, and reduce their screen time in front of children so as\nto set healthy standards in the home.</li>\n<li>Blink. Breathe. Break.</li>\n</ul>\n\n<p>Also check the following image as a guidance:</p>\n\n<p><a href=\"https://i.stack.imgur.com/zhAW3.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/zhAW3.jpg\" alt=\"Computer Eye-gonomics - tips to prevent and lessen digital eye strain\"></a></p>\n\n<p>Source: <a href=\"https://www.thevisioncouncil.org/sites/default/files/TVCDigitEYEzedReport2013.pdf\" rel=\"noreferrer\">Digiteyezed - The daily impack of digital screens on the eye health of Americans</a></p>\n", "score": 6 } ]

[ "eye", "computers", "lifestyle" ]

[ { "answer_id": 495, "body": "<p>The best long-term perfect posture is subjective due to the variety of body types, incorrect posture differs from person to person and person's proper posture can be incorrect posture for someone else and vice versa.</p>\n\n<p>Usually the good sitting posture can be determined by the following methods:</p>\n\n<ul>\n<li>Support your back to avoid back pain.</li>\n<li>Adjust your chair.</li>\n<li>Rest your feet on floor.</li>\n<li>If you're using computer, then:\n\n<ul>\n<li>place your screen at eye level,</li>\n<li>place your keyboard in front of you when typing,</li>\n<li>position and use the mouse as close to you as possible,</li>\n<li>avoid screen reflection,</li>\n<li>if using spectacles, it's important to see the screen easily without having to raise or lower your head.</li>\n</ul></li>\n<li>Make frequently used objects accessible (such as telephone, stapler),\nso you can avoid repeated stretching or twisting to reach things.</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/Livewell/workplacehealth/Pages/howtositcorrectly.aspx\" rel=\"noreferrer\">How to sit correctly</a> at NHS}</p>\n\n<p>The common mistakes involve:</p>\n\n<ul>\n<li><p>Hunched back and 'text neck'.</p>\n\n<p><img src=\"https://i.stack.imgur.com/g0w2h.jpg\" alt=\"Hunched back and &#39;text neck&#39;.\"></p>\n\n<blockquote>\n <p>When hunching over a computer, your head may tend to lean forward, which can cause stiffness and pain in the neck.</p>\n \n <p>Over time, this type of posture can contribute to you developing a rounded upper back, a condition called kyphosis, which can cause shoulder and upper back stiffness and pain.</p>\n</blockquote></li>\n<li><p>Poking your chin.</p>\n\n<p><img src=\"https://i.stack.imgur.com/PZqlp.jpg\" alt=\"Poking your chin.\"></p>\n\n<blockquote>\n <p>The poking chin posture is often caused by sitting too low, a screen set too high, a hunched back or a combination of all three.</p>\n \n <p>A poking chin posture can lead to muscle weakness around the neck, compressing the neck joints, which over time can lead to stiffness and pain in the neck, shoulders and upper back and cause headaches.</p>\n</blockquote></li>\n<li><p>Rounded shoulders.</p>\n\n<p><img src=\"https://i.stack.imgur.com/0z2TC.jpg\" alt=\"Rounded shoulders.\"></p>\n\n<blockquote>\n <p>Rounded shoulders are typically caused by poor posture habits, muscle imbalances and an uneven exercise regimen, such as too much focus on chest strength and neglecting the upper back.</p>\n \n <p>Over time, these muscle imbalances will result in poor positioning of your shoulders, which can lead to shoulder and neck stiffness and pain.</p>\n</blockquote></li>\n<li><p>Sitting cross legged.</p>\n\n<p><img src=\"https://i.stack.imgur.com/CG2ic.jpg\" alt=\"Sitting cross legged.\"></p>\n\n<blockquote>\n <p>Over time you may develop muscle imbalances in your hips, which can cause stiffness and pain in the hips and lower back.</p>\n</blockquote></li>\n<li><p>Cradling your phone.</p>\n\n<p><img src=\"https://i.stack.imgur.com/gMjCJ.jpg\" alt=\"Cradling your phone.\"></p></li>\n<li><p>Slouching in a chair.</p>\n\n<p><img src=\"https://i.stack.imgur.com/E40ZE.jpg\" alt=\"Slouching in a chair.\"></p></li>\n</ul>\n\n<p>^{<a href=\"http://www.nhs.uk/Livewell/Backpain/Pages/back-pain-and-common-posture-mistakes.aspx\" rel=\"noreferrer\">Common posture mistakes and fixes</a> at NHS}</p>\n\n<p><a href=\"https://en.wikipedia.org/wiki/Poor_posture\" rel=\"noreferrer\">Wikipedia</a> summarise that in the following way:</p>\n\n<ul>\n<li><p>rounded and elevated shoulders and a pushed-forward head position,</p>\n\n<blockquote>\n <p>This position places stress on the spine between the top of the neck and skull and the base of the neck and upper shoulders.</p>\n</blockquote></li>\n<li><p>a forward tilting of the hips which is increasing the curve of the lumbar spine, and a protruding stomach</p>\n\n<blockquote>\n <p>This position places stress over both the hip joints and lower back.</p>\n</blockquote></li>\n</ul>\n\n<p>Poor posture can result in musculoskeletal distortion in the neck, and lower and upper back, it can also impede the ability of the lungs to expand and many other injuries.</p>\n\n<p>When the posture is correct, it allows your body muscles to breathe at optimum capacity.</p>\n", "score": 24 }, { "answer_id": 5659, "body": "<p>Short answer: <em>there is <strong>no best long-term sitting</strong> posture</em>. If there is any, <em><strong>take care of posture</strong> (I'd risk to say <strong>upright</strong> is best)</em>, and move every certain amount of time in the chair and/or around.</p>\n\n<p>I'm for positive responses so let me elaborate a bit more. All cautious considerations, as <code>kenorb</code> properly states, are ok. However, even if some of those considerations attend to the actual question, which was <em>what should I DO when sitting?</em> (notice the question was not pointed so much as to what NOT doing). What follows is an intent to give further argumentation in how to achieve the goal of sitting in a way that can take care of good posture in general, how and mostly why.</p>\n\n<p>Rather move around once in a while, and shift between different subtle positions. When you are sitting for long, you don't want to atrofiate your muscles, nor your posture. Hence several considerations: </p>\n\n<ul>\n<li><p>Check the post <a href=\"http://health.stackexchange.com/questions/124/why-is-sitting-for-long-periods-unhealthy?rq=1\">sitting is the new smoking</a>, and the main answer: <em>The solution is simple. Move.</em></p></li>\n<li><p>Consider that <strong>what you need to take care of</strong> when sitting <strong>is your whole body/organism</strong>, and not just a part.</p></li>\n<li><p>When sitting backwards you can alleviate your lower back for a while, but doing so as a norm can weaken that area as well.</p></li>\n<li><p>Remember that the human posture, standing or sitting or moving, has a certain balance. We have anterior and posterior muscles surrounding our body to make this balance possible. This is why I would infer that if one has <em>bad posture</em> (not necesarily back problems) along the day...reclining can be more easy going. But in the same coin, in the long run this may not favor good posture and a distributed and balanced muscle development.</p></li>\n<li><p>The study you mention says that <em>the 135-degree posture, suggesting less strain is placed on the spinal disks</em>. Of course this may be true, but to conclude from that that it'd be best to not sit at 90º is rather far fetched. I figure in some way that the article suggests that maximum relaxation can always be best. But in reality: (<em>if we assume not to be jello floating in a liquid environment</em>) <strong>we do need a certain amount of tension</strong> to function properly. Remember the fat moveless couch potatoes from the movie <a href=\"http://www.imdb.com/title/tt0910970/\" rel=\"nofollow noreferrer\">Wall-E</a> that underdevelop muscles and even bone-structure.</p></li>\n<li><p>Again, the reference you take mentions volunteers with <em>healthy backs</em>, this ussualy means that they'd have no problems in that area, but I'd argue that not many people reach a full healthy posture in a broader sense.</p></li>\n<li><p>See what kind of chair you have available. Some may favor a certain way of sitting or several.</p></li>\n</ul>\n\n<p>Also, <a href=\"http://www.bodyconsciousdesign.com/uploads/interview_galen_cranz_portland.pdf\" rel=\"nofollow noreferrer\">Galen Cranz's been researching <strong>chairs</strong>: here interview and book reference</a>.</p>\n\n<hr>\n\n<p>Since many people don't only sit, but also are <em>in front of a pc</em> let me add:</p>\n\n<ul>\n<li><p>If you can use a keyboard near your lap, this can be better than having it a higher level. I find the latter to thrust your elbows, shoulders, upper-back and neck upwards.</p></li>\n<li><p>Consider, like apple co-creator Oz Wozniak did: <a href=\"https://tex.stackexchange.com/a/310958/93818\">Dvorak</a>'s effort and resulting keyboard configuration. The main aim there is not for speed but for comfort, and avoiding carpal tunnel syndrome. </p></li>\n</ul>\n", "score": 7 }, { "answer_id": 12849, "body": "<p>From my experience, it is better to change postures while you sit long. </p>\n\n<p>Most often, I sit in a posture similar to below yoga posture 'Padmasana' in my chair, but not for so long, just for 5 or 10 minutes. It really helps to reduce the tension on the back. </p>\n\n<p>Actually, it need not be in exactly this position, just cross your legs as you can. After 5 or 10 minutes you can go back to your normal sitting posture as suggested in above answers. Whenever you feel tension on the back just try this posture for a few minutes.</p>\n\n<p>Try this out and see how it goes.</p>\n\n<p><a href=\"https://i.stack.imgur.com/c12R2.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/c12R2.jpg\" alt=\"enter image description here\"></a></p>\n", "score": 1 } ]

[ "research", "lifestyle", "back", "posture", "sitting" ]

[ { "answer_id": 39, "body": "<p>The IARC has concluded that <a href=\"http://www.cancer.gov/cancertopics/causes-prevention/risk/radiation/cell-phones-fact-sheet\">cell phones are a \"possible carcinogen\"</a> due to the amount of evidence going both directions.</p>\n\n<p>The gist of it is summarised on the website itself:</p>\n\n<blockquote>\n <ul>\n <li>Cell phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can be absorbed by tissues closest to\n where the phone is held.</li>\n <li><p>The amount of radiofrequency energy a cell phone user is exposed to depends on the technology of the phone, the distance between the\n phone’s antenna and the user, the extent and type of use, and the\n user’s distance from cell phone towers.</p></li>\n <li><p>Studies thus far have not shown a consistent link between cell phone use and cancers of the brain, nerves, or other tissues of the head or\n neck. More research is needed because cell phone technology and how\n people use cell phones have been changing rapidly.</p></li>\n </ul>\n</blockquote>\n\n<p>_{<a href=\"http://www.sciencedirect.com/science/article/pii/S0928468014000649\">Mobile phone and cordless phone use and the risk for glioma – Analysis of pooled case-control studies in Sweden, 1997–2003 and 2007–2009</a>} </p>\n", "score": 34 }, { "answer_id": 5856, "body": "<blockquote>\n <p>Exposure to ionizing radiation, such as from x-rays, is known to increase the risk of cancer. However, although many studies have examined the potential health effects of non-ionizing radiation from radar, microwave ovens, cell phones, and other sources, there is currently no consistent evidence that non-ionizing radiation increases cancer risk <a href=\"http://ec.europa.eu/health/scientific_committees/emerging/docs/scenihr_o_041.pdf\" rel=\"noreferrer\">(1)</a>.</p>\n</blockquote>\n\n<p><strong>Source</strong>: <a href=\"http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet#q2\" rel=\"noreferrer\">http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet#q2</a></p>\n\n<p>You might find my answer to <a href=\"https://health.stackexchange.com/questions/5847/is-wi-fi-harmful-to-ones-health\">this question</a> helpful.</p>\n", "score": 11 } ]

[ "cancer", "brain", "cellular-phone", "bioelectromagnetics", "health-outcomes" ]

[ { "answer_id": 681, "body": "<p>Metabolic rate, individual genetics, cholesterol-absorption controversies, nutrients of the egg, size of the egg, and definition of \"maximum\" all contribute to ambiguity.\n<a href=\"http://www.eggnutritioncenter.org/egg-facts/nutrition-facts-panels/\">This list of egg sizes and corresponding nutrition panels with daily recommended values is a good starting place</a>, but I will also address this in a general context of what experts recommend and nutrient content.</p>\n\n<p><strong>Cholesterol</strong></p>\n\n<p>When people talk about eggs, they usually want to talk about cholesterol.</p>\n\n<p>The problem is that the body doesn't fully absorb all of the cholesterol, so there's no hard rule. What we do know is:</p>\n\n<ul>\n<li>A large egg contains about 185 mg of cholesterol. <a href=\"http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/cholesterol/FAQ-20058468\">{2}</a></li>\n<li>Although there is no precise basis for selecting a target level for<br>\ndietary cholesterol intake for all individuals, the AHA recommends<br>\n&lt;300 mg/d on average. <a href=\"http://circ.ahajournals.org/content/102/18/2284.full\">{3}</a></li>\n<li>Your body doesn't absorb everything you eat. (That's part of why we go to the bathroom.)</li>\n</ul>\n\n<p>Registered dietitian Leslie Beck recommends:</p>\n\n<blockquote>\n <p>People at high risk for cardiovascular disease – e.g. people with diabetes, high cholesterol, and/or hypertension and smokers – should definitely limit their intake of egg yolks... some experts advise avoidance.</p>\n</blockquote>\n\n<p>However, for healthy people with no medical condition, regular exercise and maintaining a healthy weight are better strategies to guard against heart disease and stroke, not cutting down on eggs (for <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16340654/\">70</a> - <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21776466\">75%</a> of the population). The two studies cited indicate that consumption of eggs does not raise cholesterol levels significantly for about 3/4ths of the population.</p>\n\n<p><strong>Fat and Calories</strong></p>\n\n<p>Each egg yolk contains 6 g of fat and 54 kcal. Even though they're full of nutrients, they still do contain calories, so factor that into your daily intake. Someone who does an average amount of physical activity would probably require an average amount of eggs. Definitely not something on the level of dozens, but even so, giving any numbers would be hard since there are so many factors in play.</p>\n\n<p><strong>Vitamins and Minerals</strong></p>\n\n<p>Eggs are naturally rich in vitamin B2 (riboflavin), vitamin B12, vitamin D, selenium and iodine. They also contain vitamin A and a number of other B vitamins including folate, biotin, pantothenic acid and choline, and essential minerals and trace elements, including phosphorus. <a href=\"http://www.egginfo.co.uk/egg-nutrition#sthash.ueExphBh.dpuf\">{6}</a></p>\n\n<p>Before reaching a daily recommended value of any of these nutrients though, you would probably far exceed the daily recommended values for fat and calories first, but it's possible to overdose on anything, so be sure to keep track of how much of these nutrients are in each egg that you consume in the event that you're burning off all the fat and calories.</p>\n\n<p><strong>Summary</strong></p>\n\n<p>To know your \"maximum\" number of eggs, you should probably talk to a dietitian.</p>\n\n<p><strong>Sources</strong></p>\n\n<ul>\n<li><a href=\"http://www.eggnutritioncenter.org/egg-facts/nutrition-facts-panels/\">http://www.eggnutritioncenter.org/egg-facts/nutrition-facts-panels/</a></li>\n<li><a href=\"http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/cholesterol/FAQ-20058468\">http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/cholesterol/FAQ-20058468</a></li>\n<li><a href=\"http://circ.ahajournals.org/content/102/18/2284.full\">http://circ.ahajournals.org/content/102/18/2284.full</a></li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16340654/\">http://www.ncbi.nlm.nih.gov/pubmed/16340654/</a></li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21776466\">http://www.ncbi.nlm.nih.gov/pubmed/21776466</a></li>\n<li><a href=\"http://www.egginfo.co.uk/egg-nutrition#sthash.ueExphBh.dpuf\">http://www.egginfo.co.uk/egg-nutrition#sthash.ueExphBh.dpuf</a></li>\n</ul>\n", "score": 30 } ]

[ "nutrition" ]

[ { "answer_id": 477, "body": "<p><strong>TL;DR</strong>: No, food cooked via a microwave oven is generally not less healthy than food cooked by other methods. </p>\n\n<hr>\n\n<p>In general, cooking by any method destroys or reduces nutrient value^{<a href=\"http://healthyeating.sfgate.com/cooking-food-reduce-vitamin-content-5164.html\" rel=\"nofollow noreferrer\" title=\"Does Cooking Food Reduce the Vitamin Content?\">1</a>,<a href=\"http://www.nytimes.com/2006/10/17/health/17real.html?_r=0\" rel=\"nofollow noreferrer\" title=\"The Claim: Microwave Ovens Kill Nutrients in Food\">4</a>}. This is due to a number of factors:</p>\n\n<ul>\n<li><p>Solubility. Water-soluble nutrients (like Vitamin B, C) are highly prone to leach out if cooking in water^{<a href=\"http://recipes.howstuffworks.com/fresh-ideas/dinner-food-facts/does-cooking-vegetables-diminish-their-nutrients.htm\" rel=\"nofollow noreferrer\" title=\"Does cooking vegetables diminish their nutrients?\">2</a>} (boiling, for example). Fat-soluble nutrients are at a similar risk when cooking in a fat medium or when the fat is lost in the process (e.g., frying, grilling)^{<a href=\"http://www.eufic.org/article/en/expid/cooking-review-eufic/\" rel=\"nofollow noreferrer\" title=\"The Why, How and Consequences of cooking our food\">5</a>}.</p></li>\n<li><p>Heat. Both fat- and water-soluble nutrients are susceptible to heat from any cooking source, while mineral nutrients are less so^{<a href=\"http://www.eufic.org/article/en/expid/cooking-review-eufic/\" rel=\"nofollow noreferrer\" title=\"The Why, How and Consequences of cooking our food\">5</a>}. </p></li>\n<li><p>Duration. Methods with shorter cook times (e.g., stir-frying, blanching, microwaving) reduce the effects of heat degradation because the food is not exposed to heat for as long^{<a href=\"http://www.eufic.org/article/en/expid/cooking-review-eufic/\" rel=\"nofollow noreferrer\" title=\"The Why, How and Consequences of cooking our food\">5</a>}.</p></li>\n</ul>\n\n<p>(It's not even always a loss: some nutrients are <em>more</em> available after cooking, because heat breaks down thick cell walls that our digestive system has trouble with, which means that the nutrients are easier for our bodies to uptake^{<a href=\"http://www.scientificamerican.com/article/raw-veggies-are-healthier/\" rel=\"nofollow noreferrer\" title=\"Fact or Fiction: Raw veggies are healthier than cooked ones\">3</a>}.)</p>\n\n<p>Each cooking method has a <strong>different combination</strong> of the above factors, and so has different effects on nutrients in food. Microwave cooking has the advantage of not cooking in water, and being able to reach a higher heat in a shorter time. Depending on the food, this means that microwaving is sometimes <em>better</em> at preserving nutrients. For example, boiling spinach causes a much higher loss (77% vs. almost none) of <a href=\"http://en.wikipedia.org/wiki/Folic_acid\" rel=\"nofollow noreferrer\">folate</a> compared to microwaving^{<a href=\"http://www.nytimes.com/2006/10/17/health/17real.html?_r=0\" rel=\"nofollow noreferrer\" title=\"The Claim: Microwave Ovens Kill Nutrients in Food\">4</a>}.</p>\n\n<p>Of course, when people make claims about microwaved food being less healthy, they are <em>usually</em> referring to a fear that the act of microwave heating (<a href=\"http://en.wikipedia.org/wiki/Dielectric_heating#Microwave_heating\" rel=\"nofollow noreferrer\">dielectric heating</a>) is 'unnatural' in some way, or is subjecting the food to dangerous radiation (which may then be ingested). This is simply not supported^{<a href=\"http://www.fda.gov/radiation-emittingproducts/resourcesforyouradiationemittingproducts/ucm252762.htm\" rel=\"nofollow noreferrer\" title=\"Microwave Oven Radiation\">9</a>} by scientific literature, which indicates that microwave ovens, when used properly, are safe and effective -- with <strong>two caveats</strong>:</p>\n\n<ul>\n<li><p>Human milk. The CDC^{<a href=\"http://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm\" rel=\"nofollow noreferrer\" title=\"Proper Handling and Storage of Human Milk\">6</a>} does not recommend heating human milk in the microwave, because of the risk of uneven heating of the liquid (which could scald a baby), and because there is some evidence^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1557249\" rel=\"nofollow noreferrer\" title=\"Effects of microwave radiation on anti-infective factors in human milk\">7</a>} that it decreases its anti-infective properties.</p></li>\n<li><p>Superheating of liquids. If water is heated in a microwave in a smooth container, it can pose a risk of scalding due to superheating^{<a href=\"http://www.fda.gov/radiation-emittingproducts/resourcesforyouradiationemittingproducts/ucm252762.htm\" rel=\"nofollow noreferrer\" title=\"Microwave Oven Radiation\">9</a>}. From <a href=\"http://en.wikipedia.org/wiki/Superheating#Occurrence_via_microwave_oven\" rel=\"nofollow noreferrer\" title=\"Superheating: Occurrence via microwave oven\">wikipedia</a>:</p>\n\n<blockquote>\n <p>Superheating can occur when an undisturbed container of water is heated in a microwave oven. When the container is removed, the water still appears to be below the boiling point. However, once the water is disturbed, some of it violently flashes to steam, potentially spraying boiling water out of the container. [...] There are ways to prevent superheating in a microwave oven, such as putting a popsicle stick in the glass or using a scratched container.</p>\n</blockquote></li>\n</ul>\n\n<p>In conclusion, microwaving food is a safe alternative to cooking via other methods^{<a href=\"http://www.fda.gov/radiation-emittingproducts/resourcesforyouradiationemittingproducts/ucm252762.htm\" rel=\"nofollow noreferrer\" title=\"Microwave Oven Radiation\">9</a>}. Any cooking method will decrease the nutritional value of food, but this is usually an acceptable tradeoff because of the benefits gained from cooking^{<a href=\"http://www.eufic.org/article/en/expid/cooking-review-eufic/\" rel=\"nofollow noreferrer\" title=\"The Why, How and Consequences of cooking our food\">5</a>}. Microwaves do not cause food to be radioactive or acutely dangerous in any way.</p>\n\n<h3>References</h3>\n\n<ol>\n<li><a href=\"http://healthyeating.sfgate.com/cooking-food-reduce-vitamin-content-5164.html\" rel=\"nofollow noreferrer\" title=\"Does Cooking Food Reduce the Vitamin Content?\">Does Cooking Food Reduce the Vitamin Content?</a> - SFGate</li>\n<li><a href=\"http://recipes.howstuffworks.com/fresh-ideas/dinner-food-facts/does-cooking-vegetables-diminish-their-nutrients.htm\" rel=\"nofollow noreferrer\" title=\"Does cooking vegetables diminish their nutrients?\">Does cooking vegetables diminish their nutrients?</a> - HowStuffWorks</li>\n<li><a href=\"http://www.scientificamerican.com/article/raw-veggies-are-healthier/\" rel=\"nofollow noreferrer\" title=\"Fact or Fiction: Raw veggies are healthier than cooked ones\">Fact or Fiction: Raw veggies are healthier than cooked ones</a> - Scientific American</li>\n<li><a href=\"http://www.nytimes.com/2006/10/17/health/17real.html?_r=0\" rel=\"nofollow noreferrer\" title=\"The Claim: Microwave Ovens Kill Nutrients in Food\">The Claim: Microwave Ovens Kill Nutrients in Food</a> - New York Times</li>\n<li><a href=\"http://www.eufic.org/article/en/expid/cooking-review-eufic/\" rel=\"nofollow noreferrer\" title=\"The Why, How and Consequences of cooking our food\">The Why, How and Consequences of cooking our food</a> - European Food Information Council</li>\n<li><a href=\"http://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm\" rel=\"nofollow noreferrer\" title=\"Proper Handling and Storage of Human Milk\">Proper Handling and Storage of Human Milk</a> - Centers for Disease Control</li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1557249\" rel=\"nofollow noreferrer\" title=\"Effects of microwave radiation on anti-infective factors in human milk\">Effects of microwave radiation on anti-infective factors in human milk</a> - Quan R, Yang C, Rubinstein S, Lewiston NJ, Sunshine P, Stevenson DK, Kerner JA Jr. Pediatrics. 1992 Apr;89(4 Pt 1):667-9.</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Superheating#Occurrence_via_microwave_oven\" rel=\"nofollow noreferrer\" title=\"Superheating: Occurrence via microwave oven\">Superheating: Occurrence via microwave oven</a> - Wikipedia</li>\n<li><a href=\"http://www.fda.gov/radiation-emittingproducts/resourcesforyouradiationemittingproducts/ucm252762.htm\" rel=\"nofollow noreferrer\" title=\"Microwave Oven Radiation\">Microwave Oven Radiation</a> - U.S. Food and Drug Administration</li>\n</ol>\n", "score": 30 }, { "answer_id": 460, "body": "<p>Heat in a microwave oven is generated by the rotation of water molecules by bombarding them with electromagnetic radiation in the microwave spectrum (non-ionizing electromagnetic waves between common radio waves and infrared frequencies) causing polarized molecules in the food to rotate or collide and subsequently thermal energy is built up (<a href=\"http://en.wikipedia.org/wiki/Dielectric_heating\">dielectric heating</a>).</p>\n\n<h3>Heat-sensitive vitamins and nutrients</h3>\n\n<p>One 1998 study shown that microwaving food can lead to faster breakdown of vitamin B₁₂^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10554220\">1998</a>}. This is because microwaved food can get locally hotter than the boiling point of water (100°C/212°F).</p>\n\n<p>Another <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17979232\">study from 2007 by J. Agric. Food Chem.</a> show a general decrease in the levels of all the studied compounds except for mineral nutrients which were stable under all cooking conditions:</p>\n\n<blockquote>\n <p>Vitamin C showed the greatest losses mainly because of degradation and leaching, whereas losses for phenolic compounds and glucosinolates were mainly due to leaching into water. In general, the longest microwave cooking time and the higher volume of cooking water should be avoided to minimize losses of nutrients.</p>\n</blockquote>\n\n<p>So it seems that the most heat-sensitive nutrients such as folic acid, vitamins B and C (mainly water-soluble vitamins)are the most affected when microwaving food.</p>\n\n<h3>Broccoli</h3>\n\n<p>One study published in The Journal of the Science of Food and Agriculture in 2003 found that microwave cooking destroyed more flavonoids than other methods. When steamed or cooked without water, the broccoli retained most of its nutrients and antioxidants.</p>\n\n<p>Loss of flavonoids in Broccoli Study:</p>\n\n<ul>\n<li>Microwaved: 97%</li>\n<li>Boiled :66%</li>\n<li>Pressure Cooked: 47%</li>\n</ul>\n\n<p>According to Dr Cristina García-Viguera, leader of the study:</p>\n\n<blockquote>\n <p>During microwave heating they leach into the cooking water, removing their nutritional benefits from the foodstuff.</p>\n</blockquote>\n\n<p>However other studies didn't show a high loss of nutrients with microwave cooking, in fact two studies indicate that microwave cooking helps retain flavonoids better than other methods.</p>\n\n<p>^{Source: <a href=\"http://www.bellaonline.com/articles/art52758.asp\">Healthy Microwave Cooking of Vegetables</a>}</p>\n\n<h3>Tomatoes</h3>\n\n<p>Loss of flavonoids from Tomatoes:</p>\n\n<ul>\n<li>Microwaved 65%</li>\n<li>Boiled 82%</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.bellaonline.com/articles/art52758.asp\">Healthy Microwave Cooking of Vegetables</a>}</p>\n\n<h3>Potatoes</h3>\n\n<p>Loss of flavonoids from Potatoes:</p>\n\n<ul>\n<li>Microwaved 45%</li>\n<li>Boiled 60%</li>\n<li>Baked 100%\n^{Source: <a href=\"http://www.bellaonline.com/articles/art52758.asp\">Healthy Microwave Cooking of Vegetables</a>}</li>\n</ul>\n\n<p>To minimize phenolic losses in potatoes, microwaving should be done at 500W^{<a href=\"http://www.sciencedirect.com/science/article/pii/S0023643808000509\">2008</a>}.</p>\n\n<h3>Spinach</h3>\n\n<p>Study at Cornell University showed that spinach retains nearly all its folate when cooked in a microwave^{<a href=\"http://www.nytimes.com/2006/10/17/health/17real.html\">NYT</a>}.</p>\n\n<h3>Bacon</h3>\n\n<p>Study at Cornell University found that bacon cooked by microwave has significantly lower levels of cancer-causing nitrosamines than conventionally cooked bacon^{<a href=\"http://www.nytimes.com/2006/10/17/health/17real.html\">NYT</a>}.</p>\n\n<h3>Acrylamide health risks</h3>\n\n<p>Acrylamide is considered a potential occupational carcinogen by U.S. government agencies^{<a href=\"https://en.wikipedia.org/wiki/Acrylamide\">wiki</a>} and it can be found in starchy foods, such as potato chips/crisps, French fries and bread that had been heated higher than 120°C (248°F)^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12166997\">2002</a>}. Acrylamide levels appear to rise as food is heated for longer periods of time.</p>\n\n<p>Unlike frying and baking, based on FDA studies^{<a href=\"http://www.fda.gov/Food/FoodborneIllnessContaminants/ChemicalContaminants/ucm151000.htm\">2008</a>}, microwaving whole potatoes with skin on to make “microwaved baked potatoes” does not produce acrylamide, although unlike deep-frying, it has limited effectiveness in reducing glycoalkaloid (i.e. solanine) levels^{<a href=\"http://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/picoline_508.pdf\">1999</a>}.</p>\n\n<p>However acrylamide can been found in other microwaved products such as popcorn.</p>\n\n<h3>Foodborne illness</h3>\n\n<p>Microwave ovens are frequently used for reheating leftover food, and bacterial contamination may not be repressed if the safe temperature is not reached, resulting in <a href=\"https://en.wikipedia.org/wiki/Foodborne_illness\">foodborne illness</a>.</p>\n\n<h3>Radiation</h3>\n\n<p>The radiation produced by a microwave oven is non-ionizing (in comparison to X-rays and high-energy particles which are associated with the cancer risks).</p>\n\n<p>Long-term studies to assess cancer risk have so far failed to identify any carcinogenicity microwave radiation (2.45GHz) even with chronic exposure levels^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/9806599\">1998</a>, <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/9453703\">1998</a>}.</p>\n\n<p>However, with the oven door open, the radiation may cause damage by heating, although the modern design of microwave ovens is equipped with safety switches that turn off the radiation when the door is open and ovens are sufficiently insulated to allow only \"minimal leakage\" when the oven is working.</p>\n\n<h3>Conclusion</h3>\n\n<p>Any form of cooking will destroy vitamins and other nutrients in food, but it depends how much water is used in the cooking, how long the food is cooked and at what temperature^{<a href=\"http://www.nytimes.com/2006/10/17/health/17real.html\">2006</a>}.</p>\n\n<p>However comparative cooking method studies generally find that, if properly used, microwave cooking does not affect the nutrient content of foods to a larger extent than conventional heating^{<a href=\"http://www.emeraldinsight.com/doi/abs/10.1108/00346659510088654\">1995</a>}.</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Microwave_oven#Effects_on_food_and_nutrients\">Microwave: Effects on food and nutrients</a> at Wikipedia</li>\n<li><a href=\"http://www.cfs.gov.hk/english/programme/programme_rafs/files/microwave_ra_e.pdf\">Microwave cooking and food safety</a> at CFS</li>\n</ul>\n", "score": 16 } ]

[ "nutrition", "bioelectromagnetics", "microwaves" ]

[ { "answer_id": 37, "body": "<p>One of the greatest benefits of MRI scans is their safety. Unlike PET, X-ray, CT and most other scans, MRIs use the properties of body tissues in magnetic fields to produce an image. The MRI machine produces a powerful magnetic field which interacts with body tissues to produce radio waves, which are in turn interpreted by a computer to determine the location of the tissues.<a href=\"http://www.nhs.uk/Conditions/MRI-scan/Pages/How-does-it-work.aspx\" rel=\"noreferrer\">¹</a></p>\n<p>This does not, however, mean MRIs are completely without risk. First and foremost, an MRI machine is basically a giant magnet. If one has metal in his or her body, from a medical implant, car accident, or even an improperly done tattoo, the MRI machine can move it, potentially violently. In the case of medical implants, an MRI machine can easily destroy any electrical components.<a href=\"http://www.asnr.org/patientinfo/procedures/mri.shtml#block2\" rel=\"noreferrer\">²</a> There are a number of different reasons metal might be present in the body.<a href=\"http://www.nhs.uk/Conditions/MRI-scan/Pages/Who-can-use-it.aspx\" rel=\"noreferrer\">³</a> This is why MRI technologists are trained to ask, repeatedly, about any metal that may be present.</p>\n<p>In addition to metal, some MRIs involve contrast media, chemicals injected or consumed that increase visibility of certain tissues in MRI scans. These chemicals are normally removed by the body rather quickly, and except in individuals with reduced kidney function, are for the most part safe. However, there have been cases of allergic reactions and side effects.<a href=\"http://www.insideradiology.com.au/pages/view.php?T_id=38#.VRsOKzvF_pb\" rel=\"noreferrer\">⁴</a> Also, recently, questionable studies have presented possible links between gadolinium-based contrast agents and nephrogenic systemic fibrosis, though the American FDA has stated that this link is only significant in patients with kidney disease, as <em>&quot;NSF has not been reported in patients with normal kidney function&quot;</em>.<a href=\"https://www.fda.gov/Drugs/DrugSafety/ucm223966.htm\" rel=\"noreferrer\">⁵</a></p>\n<h3>In Short</h3>\n<p>In healthy individuals, with properly-functioning kidneys, no medical implants, no improperly-done tattoos, and no metal embedded in the body, MRIs are completely safe, once or even quite often.</p>\n", "score": 44 }, { "answer_id": 24, "body": "<p>While they're sometimes confused by the public, X-Ray CT (computed tomography) and MRI (magnetic resonance imaging) work by entirely different priniciples. X-Ray radiation is harmful, and any unnecessary exposure should be limited. MRI works by putting the subject into a very strong magnetic field and using radiowaves to excite specific nuclei. </p>\n\n<p>The potential dangers of MRI are equivalent to the dangers of strong magnetic fields and radiowaves (and potentially any contrast medium that is used, which can cause allergic reactions). </p>\n\n<p><a href=\"http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm200086.htm\">According to the FDA:</a></p>\n\n<blockquote>\n <p>There are no known harmful side-effects associated with temporary exposure to the strong magnetic field used by MRI scanners. </p>\n</blockquote>\n\n<p>Due to the strong magnetic field you need to avoid bringing any metal objects near the MRI, they will be attracted by the magnet and become dangerous projectiles.</p>\n", "score": 28 } ]

[ "side-effects", "mri", "medical-imaging", "bioelectromagnetics" ]

[ { "answer_id": 14, "body": "<p>I believe that those lines are craze lines. <strong>\"Craze lines are merely cracks in the enamel that do not extend into the dentin.\"</strong> They occur because of stress in your teeth, ie: grinding your teeth, biting your nails, and even routine use of your teeth. What you've said also matches up with craze lines in that you don't experience any pain. Those craze lines aren't nearly as bad as some other teeth. Craze lines rarely lead to tooth breakdown, so you almost definitely won't have to get them replaced. There are some studies that say that craze lines may be spots where cavities can form, but these potential problems can be easily detected by dentists.</p>\n\n<p>Most craze lines, like the ones below, are much worse than yours.</p>\n\n<p><img src=\"https://i.stack.imgur.com/7VFy0.jpg\" alt=\"Craze Lines\"></p>\n\n<hr>\n\n<p><a href=\"http://www.oralanswers.com/craze-lines-in-teeth/\" rel=\"noreferrer\">^{Craze Lines: Hairline Cracks In Your Front Teeth\n}</a></p>\n", "score": 35 } ]

[ "dentistry" ]

[ { "answer_id": 180, "body": "<p>Obviously some spicy foods are better for you than others, but I am assuming you want an answer about spicy foods in general. </p>\n\n<p>One of the biggest benefits of eating spicy foods, especially chili peppers, is that it helps you lose weight. Spicy foods help to raise your metabolic rate, which will slow down your weight gain. If you eat spicy foods often, the effects add up.¹</p>\n\n<p>A 2007 study by Nottingham University² found that spicy foods can help kill cancer cells. Capsaicin, which is what makes many foods spicy, attacks the mitochondria of the cancer cells, triggering their death. </p>\n\n<p>Spicy foods have also been found to help decongest your sinuses. A 1998 study³ found that a capsaicin nasal spray helped to clear the sinuses of people. Eating spicy foods has been known to have a similar effect.⁴</p>\n\n<hr>\n\n<p>Now for some risks of eating spicy food.</p>\n\n<p>When you are eating spicy foods, there are only a few risks to watch out for. Spicy foods have been known as foods that can trigger heartburn, so anyone with heartburn should avoid them.⁵ Some spicy foods that don't contain capsaicin, like horseradish, can sometimes damage tissue.⁶</p>\n\n<p>There are usually more risks when handling spicy foods, especially peppers. If pepper juice gets in your eye, it will cause pain and possibly swelling. If this ever happens, there are ways to flush out your eyes.⁷ Handling peppers and sometimes horseradish before eating can cause pain, swelling, redness, and irritation in your hand. To avoid this, wear gloves when cutting peppers and wash your hands thoroughly after (washing with milk will help).⁶</p>\n\n<hr>\n\n<p>^{[1] <a href=\"http://www.medicaldaily.com/chili-peppers-may-solve-obesity-epidemic-spice-your-weight-loss-these-3-recipes-321370\" rel=\"noreferrer\">Chili Peppers May Solve Obesity Epidemic</a>}</p>\n\n<p>^{[2] <a href=\"http://news.bbc.co.uk/2/hi/6244715.stm\" rel=\"noreferrer\">How spicy foods can kill cancers</a>}</p>\n\n<p>^{[3] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/9824407\" rel=\"noreferrer\">The long-term effects of capsaicin aqueous spray on the nasal mucosa</a>}</p>\n\n<p>^{[4] <a href=\"http://books.google.com/books?id=Ht4J6mvKTwMC&amp;pg=PA230&amp;dq=spicy+food+sinuses&amp;hl=en&amp;ei=LNFBTuucJK_WiALql92nBQ&amp;sa=X&amp;oi=book_result&amp;ct=result&amp;resnum=3&amp;ved=0CDUQ6AEwAg#v=onepage&amp;q=spicy%20food%20sinuses&amp;f=false\" rel=\"noreferrer\">Diseases of the Sinuses: A Comprehensive Textbook of Diagnosis and Treatment</a>}</p>\n\n<p>^{[5] <a href=\"http://www.webmd.com/heartburn-gerd/america-asks-9/spicy-foods\" rel=\"noreferrer\">Heartburn Prevention Tips for Spicy Food Lovers</a>}</p>\n\n<p>^{[6] <a href=\"http://healthyeating.sfgate.com/can-eating-extremely-spicy-food-harmful-health-2660.html\" rel=\"noreferrer\">Can Eating Extremely Spicy Food Be Harmful to Your Health?</a>}</p>\n\n<p>^{[7] <a href=\"https://lifehacks.stackexchange.com/questions/5656/removing-pepper-juice-from-eyes/5658#5658\">Removing Pepper Juice From Eyes</a>}</p>\n", "score": 42 }, { "answer_id": 403, "body": "<p>The chilli pepper is usually referred to plants from the genus Capsicum and the substances that give chili peppers their intensity when ingested or applied topically are <a href=\"http://capsaicin\" rel=\"noreferrer\">capsaicin</a> and several related (called as <a href=\"http://en.wikipedia.org/wiki/Capsaicin#Capsaicinoids\" rel=\"noreferrer\">capsaicinoids</a>).</p>\n<p>Health benefits of eating chilli peppers can include:</p>\n<ul>\n<li><p><a href=\"http://www.nhs.uk/news/2010/04april/pages/chilli-peppers-fat-burning-and-appetite.aspx\" rel=\"noreferrer\">Chilli peppers 'help to burn fat'</a> (<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21093467\" rel=\"noreferrer\">study</a>)</p>\n<blockquote>\n<p>The effects of capsaicin, the chemical that makes peppers and chillies hot, have been studied again in a small trial investigating what effects hot red (cayenne) pepper has on energy expenditure, body temperature and appetite.</p>\n</blockquote>\n</li>\n</ul>\n\n<ul>\n<li><a href=\"http://www.nhs.uk/news/2010/08august/pages/chilli-blood-pressure-link.aspx\" rel=\"noreferrer\">Chillies lower blood pressure.</a>^{<a href=\"http://www.cell.com/cell-metabolism/abstract/S1550-4131(10)00228-7\" rel=\"noreferrer\">2010</a>}</li>\n<li>Effects on gastric emptying and intestinal transit^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1543869\" rel=\"noreferrer\">1992</a>}.</li>\n</ul>\n<p>Nutritional value (per 1 pepper ~45g):</p>\n<ul>\n<li>Vitamin C: 181%</li>\n<li>Vitamin A: 10%</li>\n<li>Vitamin B-6: 5%</li>\n<li>Iron: 2%</li>\n<li>Magnesium: 2%</li>\n</ul>\n<p>Yellow and green chilies (which are essentially unripe fruit) contain lower amount of carotene and vitamin C substances.</p>\n", "score": 12 }, { "answer_id": 5008, "body": "<p>Red chilies contain large amounts of vitamin C and small amounts of carotene (provitamin A). Yellow and especially green chilies (which are essentially unripe fruit) contain a considerably lower amount of both substances. In addition, peppers are a good source of most B vitamins, and vitamin B6 in particular. They are very high in potassium, magnesium, and iron. Their very high vitamin C content can also substantially increase the uptake of non-heme iron from other ingredients in a meal, such as beans and grains.</p>\n\n<p>A very large study published by the British Medical Journal found some indications that humans who consume spicy foods, especially fresh chili peppers, were less likely to die of cancer or diabetes</p>\n\n<p><strong>Sources:</strong> </p>\n\n<ul>\n<li><a href=\"https://en.wikipedia.org/wiki/Chili_pepper\" rel=\"noreferrer\">https://en.wikipedia.org/wiki/Chili_pepper</a></li>\n<li><a href=\"http://peerh.com\" rel=\"noreferrer\">peerh.com</a></li>\n</ul>\n", "score": 12 }, { "answer_id": 15118, "body": "<p>There is one exception that has not been mentioned. There is a condition called Cholinergic Urticaria, which is hives due to excess heat and sweat. It is in the category of physical allergies, and more information can be found here: <a href=\"https://emedicine.medscape.com/article/1049978-overview?pa=g61D7%2BA62wCW%2FjnI7GiLspM9NWt99zm7nLfIhufvNaPVs%2Fv900arF62zFPcN7%2Fy5%2FFT7vVL%2FlyCPnaUOM57xWkj41%2F3Xq%2FwkYYScwkptsbo%3D\" rel=\"nofollow noreferrer\">Medscape Cholinergic Urticaria</a>. One of the triggers is spicy food. This <a href=\"https://emedicine.medscape.com/article/1049978-treatment\" rel=\"nofollow noreferrer\">article</a> explains that dietary changes that remove foods that elevate the body temperature help tame the symptoms. Removing capsaicin foods eliminates a trigger for these reactions.</p>\n", "score": 3 } ]

[ "nutrition", "risks", "benefits", "healthy-cooking" ]

[ { "answer_id": 18, "body": "<p>There is evidence that neonatal circumcision saying that the benefits of circumcision outweigh the risks.</p>\n\n<p>According to a study done on neonatal circumcision^[1], the lifetime benefits of being circumcised outweighed the risks 100 to 1. Some of the risks people may associate with circumcision are very unlikely. Excessive bleeding only happens 0.1% of the time, infections 0.02% of the time, and loss of penis 0.0001% of the time. The percentage of death is only 0.00001%. </p>\n\n<p>Overall, it shows that males who have been circumcised require half as much medical attention as males who have not been circumcised. Also, the overall risk of circumcised men having serious medical implications is 1 to 5000; this includes things like HIV and other sexually transmitted diseases. </p>\n\n<p><a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196(14)00036-6/fulltext#tbl4\">This graph</a> contains other relevant information.</p>\n\n<p>There are some people who disagree with the article mentioned above.^[2] In a direct statement against the article, it is said that the article is \"marred by bias.\" They note how the article fails to mention many things, such as statements against circumcision and harms in sexual experience. It doesn't completely refute the article that says circumcision is beneficial, but it is something good to think about.</p>\n\n<hr>\n\n<p>^{[1] <a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196(14)00036-6/fulltext#sec3\">Circumcision Rates</a>}</p>\n\n<p>^{[2] <a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196(14)00747-2/fulltext\">Bias and Male Circumcision</a>}</p>\n", "score": 26 }, { "answer_id": 427, "body": "<p>There is some evidence which supports that male circumcision reduces the risk of HIV infection among heterosexual men in sub-Saharan Africa^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21590467\">(1)</a>,<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19370585\">(2)</a>}, however the evidence of an HIV benefits for men who have sex with men is less clear^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18840841\">(3)</a>,<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21678366\">(4)</a>} and its use to prevent HIV in the developed world is unclear either^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20844437\">(5)</a>}.</p>\n\n<p>The treatment option for pathological phimosis, refractory balanoposthitis and UTIs is only contraindicated in cases of certain genital structure abnormalities or poor general health^{<a href=\"http://books.google.com/books?id=or15PgAACAAJ\">(6)</a>,<a href=\"http://books.google.com/books?id=V8lMJniWK_QC\">(7)</a>}.</p>\n\n<p>WHO recommends considering circumcision as part of a comprehensive HIV program only in areas with high rates of HIV (e.g. Africa)^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2835757/\">(8)</a>,<a href=\"http://www.who.int/hiv/mediacentre/news68/en/\">(9)</a>}.</p>\n\n<p>Therefore if you're not living in Africa or areas with high rates of HIV, the potential risks outweighs health benefits associated with circumcision. As currently no major medical organization recommends non-therapeutic neonatal circumcision, and no major medical organization calls for banning it either.</p>\n\n<p>See also: <a href=\"http://en.wikipedia.org/wiki/Circumcision\">Circumcision</a> at Wikipedia</p>\n", "score": 20 }, { "answer_id": 15635, "body": "<p>Circumcision is a form of sexual mutilation performed on male infants usually for religious reasons unrelated to putative health benefits. The claim of reduced risk for HIV infection is supported by this <a href=\"http://www.cochrane.org/CD003362/HIV_male-circumcision-for-prevention-of-heterosexual-acquisition-of-hiv-in-men\" rel=\"nofollow noreferrer\">Cochrane review</a> but applies to Africa. Another review looked at urinary tract infections and found <a href=\"http://www.cochrane.org/CD009129/NEONATAL_newborn-circumcision-for-the-prevention-of-urinary-tract-infections-in-infancy\" rel=\"nofollow noreferrer\">insufficient data</a> to draw conclusions.</p>\n\n<p>Circumcision has traditionally been conducted without analgesia and there are some data to suggest <a href=\"http://www.cirp.org/library/psych/\" rel=\"nofollow noreferrer\">stress related manifestations</a> develop in these children compared with the uncircumcised. Furthermore, there have been well publicised <a href=\"http://www.independent.co.uk/news/world/americas/herpes-babies-jewish-circumcision-ritual-link-rabbis-infants-a7620446.html\" rel=\"nofollow noreferrer\">deaths</a> resulting from the traditional Jewish practice of sucking on the foreskin to prevent bleeding causing herpes. In any other jurisdiction, this could be considered paedophilia.</p>\n\n<p>Interestingly Iceland is looking to <a href=\"https://www.theguardian.com/society/2018/feb/18/iceland-ban-male-circumcision-first-european-country\" rel=\"nofollow noreferrer\">ban</a> neonatal circumcision.</p>\n", "score": 5 } ]

[ "urology" ]

[ { "answer_id": 385, "body": "<p><strong>TL;DR</strong> - Organic foods don't seem to have a significant difference as of what studies can prove, which is why conventional or organic, people should make sure they're getting the proper nutrients that their bodies need.</p>\n\n<hr>\n\n<p><strong>Brief History of Pesticide Usage</strong></p>\n\n<p>The first recorded use of insecticides is about 4500 years ago by Sumerians who used sulphur compounds to control insects and mites, whilst about 3200 years ago the Chinese were using mercury and arsenical compounds for controlling body lice. In the 1920s there were even cases of using arsenic, which was replaced by DDT usage until the new chemical was discovered to have severe consequences (harm to <a href=\"http://www.fws.gov/contaminants/Info/DDT.html\">non-target plants and animals</a> as well as problems with <a href=\"http://www.idosi.org/ejas/4(2)12/2.pdf\">residues</a>). DDT is linked with cancer, endocrine disruption, and reproductive and developmental effects. Over time, people began to switch to organic pesticides to get away from the health scares (or threats) of these synthetic chemicals.</p>\n\n<p>To address the question, we should first be clear about what organic means.</p>\n\n<p><strong>Regarding produce:</strong></p>\n\n<blockquote>\n <p>Contrary to what most people believe, \"organic\" does not automatically mean \"pesticide-free\" or \"chemical-free\" ... it means that these pesticides, if used, must be derived from natural sources, not synthetically manufactured.</p>\n</blockquote>\n\n<p><strong>Regarding Farmed Meats (some of the key requirements):</strong></p>\n\n<ul>\n<li>Must be raised organically on certified organic land</li>\n<li>Must be fed certified organic feed</li>\n<li>No antibiotics or added growth hormones are allowed*</li>\n<li>Must have outdoor access</li>\n</ul>\n\n<p>Organic food covers a wide variety of techniques and different types of foods that all have their own types of legal loop-holes, or possible work-around strategies.</p>\n\n<p>There are many pesticides that are naturally produced by plants which farmers use, but that doesn't mean they aren't dangerous. In contrast, just because a pesticide is synthetic doesn't immediately indicate that it's more dangerous than natural products. Some pesticides that are approved by the government may be harmless in small quantities, but when organic producers attempt to refuse these, they may turn to alternatives that are even more dangerous, just to keep the label \"organic\".</p>\n\n<p>In another case, farmers could claim \"natural methods are insufficient to address critical issues of production\", and then treat their animals with antibiotics while still calling the meat organic.</p>\n\n<p>On the other side of this issue, some people argue that the less chemicals we consume in general, the better. Even if they might be government approved, that doesn't prove they're completely non-toxic.</p>\n\n<p>The Stanford paper claim that there just isn't enough evidence to prove a significant difference in health benefits/risks. They don't necessarily have more nutrients, decrease the risk of any diseases, or have higher nutritional content except for phosphorus, which most people get enough of anyways. However, the study <em>does</em> suggest organic foods contain less pesticides. The health risks of consuming less pesticides though, <strong>are still contested</strong>. \"Additionally, organic chicken and pork appeared to reduce exposure to antibiotic-resistant bacteria, <strong>but the clinical significance of this is also unclear</strong>.\"</p>\n\n<p><strong>Well what about taste?</strong></p>\n\n<blockquote>\n <p>Taste is to a large extent subjective. Add to that\n different varieties, different weather conditions, different soil\n types and different soil management practices...</p>\n</blockquote>\n\n<p><a href=\"http://www.mofga.org/Publications/MaineOrganicFarmerGardener/Summer2003/Taste/tabid/1484/Default.aspx\"> - Does Organically Grown Food Taste Better?</a></p>\n\n<p>It's nearly impossible to give a definitive answer of which tastes better. To pile onto the confusion, it's possible that the taste differences touted by some may simply derive from a <a href=\"http://www.sciencedirect.com/science/article/pii/S0950329313000141\">\"health halo\"</a>.</p>\n\n<p><strong>Genetically Modified Organisms</strong></p>\n\n<p>In response to the scares involved with pesticides in general, people began to research methods to minimize the amount of pesticide used. Basically, DNA from an external source is inserted into a plant so that the plant inherits some desirable traits. This allowed plants to develop natural immunities to certain bacteria and produce more or bigger produce. Over time, people became scared of GMOs as too good to be true. For the most part, scientists agree that GMOs pose no greater risk than conventional food (<a href=\"http://www.sciencedirect.com/science/article/pii/S0306919210000254\">Expert evaluations from Europe found no verifiable toxic or deleterious effects from GM foods and crops</a>). There are still legitimate concerns about using GMOs, such as allergy development in humans, toxicity levels of naturally produced pesticides in the plant, and <a href=\"http://civileats.com/2015/03/24/study-links-widely-used-pesticides-to-antibiotic-resistance/\">antibiotic resistance</a> of bacteria, but for the most part these are tested before distribution. Public wariness may be influenced by <a href=\"http://www.aaas.org/news/aaas-board-directors-legally-mandating-gm-food-labels-could-%E2%80%9Cmislead-and-falsely-alarm\">labels and commercialism.</a></p>\n\n<p><a href=\"http://www.fao.org/organicag/oa-faq/oa-faq6/en/\"><strong>Secondary Effects of Organic Farming</strong></a></p>\n\n<p>Organic farming is good for the environment in the sense that it often leads to less pollution. Pesticides on crops often run-off into streams and rivers, interfering and even hurting local wildlife, but with organic pesticides, the chemicals decompose faster before they can cause massive change to their environment. There may be other potential benefits, but to feed the immense population that exists on earth, many debate whether organic farming is truly sustainable. </p>\n\n<p><strong>\"Healthier\" depends on the context of the food:</strong> </p>\n\n<p>How much pesticide is being used? How much exposure becomes a detriment? Does it have long-term consequences? What are the loopholes that producers are using?</p>\n\n<p>So when you say \"organic\" and \"conventional\" it really depends on the process, producer, and product- all of which need to be studied in more detail to develop solid claims. </p>\n\n<p><strong>Citations:</strong></p>\n\n<p>History of Pesticides:</p>\n\n<ul>\n<li><p><a href=\"http://agrochemicals.iupac.org/index.php?option=com_sobi2&amp;sobi2Task=sobi2Details&amp;catid=3&amp;sobi2Id=31\">IUPAC - History of Pesticide Use</a></p></li>\n<li><p><a href=\"http://people.oregonstate.edu/~muirp/pesthist.htm\">Oregon State - History of Pesticide Use</a></p></li>\n<li><p><a href=\"http://ipm.ncsu.edu/safety/factsheets/pestuse.pdf\">Pesticide Usage in the United States: History, Benefits, Risks, and Trends</a></p></li>\n<li><p><a href=\"http://www.toxipedia.org/display/toxipedia/DDT\">Toxipedia - DDT</a></p></li>\n</ul>\n\n<p>GMOs</p>\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_organism\">Wikipedia - Genetically Modified Organism</a></li>\n</ul>\n\n<p>Secondary Effects of Organic Farming:</p>\n\n<ul>\n<li><a href=\"http://www.fao.org/organicag/oa-faq/oa-faq6/en/\">FAO - What are the environmental benefits of organic agriculture?</a></li>\n</ul>\n\n<p>Modern Pesticide Usage:</p>\n\n<ul>\n<li><p><a href=\"http://annals.org/article.aspx?articleid=1355685\">Stanford Researchers - Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review</a></p></li>\n<li><p><a href=\"http://www.health.harvard.edu/blog/organic-food-no-more-nutritious-than-conventionally-grown-food-201209055264\">Harvard - Organic food no more nutritious than conventionally grown food</a></p></li>\n<li><p><a href=\"http://med.stanford.edu/news/all-news/2012/09/little-evidence-of-health-benefits-from-organic-foods-study-finds.html\">Stanford - Little evidence of health benefits from organic foods, study finds</a></p></li>\n<li><p><a href=\"http://www.safefruitsandveggies.com/sites/default/files/organic-report.pdf\">Pesticide Use Regulations on ORGANIC Fruit and Vegetable Farms</a></p></li>\n<li><p><a href=\"http://freakonomics.com/2010/10/20/pesticide-politics/\">Pesticide Politics</a></p></li>\n<li><p><a href=\"http://www.science20.com/agricultural_realism/muddled_debate_about_pesticide_and_gm_crops-101857\">Science 20 - The Muddled Debate About Pesticide and GM Crops</a></p></li>\n</ul>\n", "score": 28 }, { "answer_id": 609, "body": "<p>In Mathematics, the <em>Annals of Mathematics</em> is the most sought after journal to have your research accept to. The article of research on this topic I am presenting was published in the <em>Annals of Internal Medicine</em>. However, I don't know if it carries the same weight. If it does, then we can rest assure that this research was meticulously scrutinized and still was able to earn a spot in the journal.</p>\n\n<p>Dr.s Crystal Smith-Spangler, Margaret L. Brandeau, Hau Lui, Patricia Schirmer, Ingram Olkin, and Dean Bravata along with Grace E. Hunter, Clay Bavinger, Maren Pearson, Vandana Sundaram, and Christopher came to the conclusion that </p>\n\n<blockquote>\n <p>Published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticides residues and antibiotic-resistant bacteria [<a href=\"https://wikis.uit.tufts.edu/confluence/download/attachments/51457571/Are+Organic+Foods+Safer+or+Healthier+Than+Conventional+Alternatives.pdf\">1</a>].</p>\n</blockquote>\n\n<p>in Are Organic Foods Safer or Healthier Than Conventional Alternatives? A Systematic Review. </p>\n\n<p>This was a non-funded study so sponsorship bias shouldn't play a role in the outcome of their work. The researchers collected data from MEDLINE, EMBASE, CAD Direct, Agricola, TOXNET, Cochrane Library, and bibliographies of retrieved articles from 1966 to 2011.</p>\n\n<p>The studies findings on Vitamin and Nutrient Levels by Food Origin:</p>\n\n<ul>\n<li>Vitamins\n<ul>\n<li>They did not find significant differences in the vitamin content of organic and conventional plant of animal products</li>\n</ul></li>\n<li>Nutrients\n<ul>\n<li>Out of the 11 nutrients reported only 2 were significantly higher in organic compared to conventional.\n<ul>\n<li>Phosphorous but the removal of one study rendered the effect size insignificant.</li>\n<li>Omega-3 fatty acids in milk and chicken</li>\n</ul></li>\n</ul></li>\n</ul>\n\n<hr>\n\n<ul>\n<li>Contaminants\n<ul>\n<li>Pesticides: detectable pesticides residues were found in 7% of organic produces and 38% of conventional produces. Organic was 30% less likely to have pesticide residue but the results statistically heterogeneous due variable levels of detection in the studies. Additionally, only three studies reported contamination exceeding maximum allowed limits.</li>\n<li>Bacterial\n<ul>\n<li>E. Coli: 7% organic; 6% conventional which is not a statistically significant difference</li>\n<li>Campylobacter in chicken: 67% organic; 64% conventional</li>\n<li>Salmonella in chicken: 35% organic; 34% conventional</li>\n<li>E. Coli in pork: 65% organic; 49% conventional</li>\n<li>Listeria monocytogenes: 3% organic; 4% conventional</li>\n</ul></li>\n</ul></li>\n<li>Antibiotic Resistance: the risk of isolating bacteria resistant to three or more antibiotics was 33% higher in conventional chicken and pork. Bacteria from retail chicken and pork had a 35% lower risk of resistance to ampicillin but the removal of one study rendered it statistically insignificant. However, of the remaining bacteria, greater resistance among bacteria from conventional methods was statistically insignificant.</li>\n<li>Fungal Toxin and Heavy Metal\n<ul>\n<li>Ochratoxin: no difference</li>\n<li>Deoxynivalenol: lower risk in organic</li>\n<li>Cadmium or lead: no difference</li>\n</ul></li>\n</ul>\n\n<p>Moreover, the researchers found publication bias in many of the articles over the 45 year period. In the discussion, the researchers write:</p>\n\n<blockquote>\n <p>Consumers purchase organic foods for many reasons. Despite the widespread perception that organically produced foods are more nutritious than conventional alternatives, we did not find robust evidence to support this perception. Only phosphorous demonstrated superiority in organic foods... although it is unlikely to be clinically significant because near-total starvation is needed to produce dietary phosphorous deficiency.</p>\n</blockquote>\n\n<p>The researchers also admit to their own publication bias:</p>\n\n<blockquote>\n <p>Studies were heterogeneous and limited in number, and publication bias may be present. </p>\n</blockquote>\n\n<p>Finally, the Mayo Clinic appears to stand by the research given in this article [<a href=\"https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/organic-food/art-20043880?reDate=20042015&amp;pg=1\">2</a>].</p>\n\n<h2>Definitions</h2>\n\n<ol>\n<li>Statistically heterogeneous: the ideals were not fully met</li>\n</ol>\n", "score": 9 }, { "answer_id": 591, "body": "<p>The more healthy can be defined in terms of nutritional value, sensory quality, and food safety.</p>\n\n<p>As we know the potential long-term health effects of exposure to pesticides can include: cancer, neurotoxic effects and many more^{<a href=\"https://en.wikipedia.org/wiki/Health_effects_of_pesticides#Long-term_effects\" rel=\"nofollow noreferrer\">wiki</a>}, because the pesticides needs to be toxic to kill pests. However under the FQPA, EPA has the authority to ensure that all pesticides meet the safety standards by setting permittable <em>tolerance</em> levels and it's testing carcinogenicity of chemicals as part of <a href=\"http://toxnet.nlm.nih.gov/cpdb/index.html\" rel=\"nofollow noreferrer\">the Carcinogenic Potency Project</a>.</p>\n\n<p>Washing and peeling conventional fruits and vegetables has only limited effect by reducing the levels of pesticides only from the surface as per USDA test data^{<a href=\"http://envirocancer.cornell.edu/FactSheet/Pesticide/fs24.consumer.cfm\" rel=\"nofollow noreferrer\">1999</a>}, but some plants can absorb pesticides systemically^{<a href=\"http://www.ewg.org/foodnews/faq.php#question_9\" rel=\"nofollow noreferrer\">EWG</a>}.</p>\n\n<p>Older studies comparing different type of foods were inconsistent. For example <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/11833635\" rel=\"nofollow noreferrer\">study from 2002</a> showed no strong evidence that organic and conventional foods differ in concentrations of various nutrients and microbiological contamination.</p>\n\n<p>The more recent study from 2006 of comparison of chemical composition and nutritional value of organically and conventionally grown plant showed that <strong>organic crops contain a significantly higher amount of certain antioxidants</strong> (vitamin C, polyphenols and flavonoids), higher dry matter content and minerals with lower level of pesticide residues, nitrate and some heavy metal contaminations. Therefore there is is a relationship between these two plant production systems and the nutritional composition of crops^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/17297755\" rel=\"nofollow noreferrer\">2006</a>}.</p>\n\n<blockquote>\n <p>Consequently, it can be concluded that organically produced plant derived food products have <strong>a higher nutritional value, including antioxidants than conventional ones</strong>. Furthermore, due to the fact that there is a <strong>lower level of contamination</strong> in organic crops, the risk of diseases caused by contaminated food is significantly reduced.</p>\n</blockquote>\n\n<p>This was confirmed by <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/24968103\" rel=\"nofollow noreferrer\">meta-analysis of 343 studies in 2014</a>.</p>\n\n<blockquote>\n <p>In conclusion, <strong>organic crops, on average, have higher concentrations of antioxidants, lower concentrations of Cd and a lower incidence of pesticide residues</strong> than the non-organic comparators across regions and production seasons.</p>\n \n <p>Additionally, the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd.</p>\n</blockquote>\n\n<p>The summary of this meta-study and antioxidant activity in ORG/CONV food can be shown in the following figures:</p>\n\n<p><img src=\"https://i.stack.imgur.com/4IfZH.jpg\" alt=\"Results of the standard unweighted and weighted meta-analyses for antioxidant activity\"></p>\n\n<p><img src=\"https://i.stack.imgur.com/Q5c9El.jpg\" alt=\"Results of the standard unweighted and weighted meta-analyses for different crop types/products for antioxidant activity\"></p>\n\n<p>^{Image source: Br J Nutr. 2014 Sep 14; 112(5): 794–811, <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141693/figure/fig3/\" rel=\"nofollow noreferrer\">Fig. 3</a> &amp; <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141693/figure/fig4/\" rel=\"nofollow noreferrer\">Fig. 4</a>}</p>\n\n<hr>\n\n<p>Based on above we can say that organic foods are more healthy than the conventional ones, because of:</p>\n\n<ul>\n<li><p>significant differences of minerals and vitamins:</p>\n\n<ul>\n<li>a higher nutritional value,</li>\n<li>higher antioxidant concentrations (vitamin C, polyphenols and flavonoids),</li>\n</ul></li>\n<li>lower incidence of pesticide residues,</li>\n<li>lower concentration of toxic/heavy metals (around 4 times less).</li>\n</ul>\n\n<p>However it can vary on agronomic practices/protocols and <a href=\"https://en.wikipedia.org/wiki/Soil_contamination\" rel=\"nofollow noreferrer\">soil pollution</a> which can affect crop composition.</p>\n\n<p>^{See also: <a href=\"https://en.wikipedia.org/wiki/Organic_food#Chemical_composition\" rel=\"nofollow noreferrer\">Organic food: Chemical composition</a> &amp; <a href=\"https://en.wikipedia.org/wiki/Pesticide_residue\" rel=\"nofollow noreferrer\">Pesticide residue</a> at Wikipedia}</p>\n", "score": 4 } ]

[ "diet", "nutrition" ]

[ { "answer_id": 361, "body": "<p>This has been a controversial dispute for a long time and it can involve a lot of personal opinion, but I will try to answer this as scientifically as possible.</p>\n<p>There hasn't been any viable evidence that vaccines do cause autism. Several different theories have been proposed on why vaccines could cause autism, such as the ingredient in some vaccines thimerosal being harmful, but these have all been disproved by many different experiments.</p>\n<p>Many reliable sources such as the <a href=\"http://www.cdc.gov/vaccinesafety/concerns/autism/\" rel=\"noreferrer\">CDC¹</a> says that there is no link between autism an vaccines. A <a href=\"https://www.ncbi.nlm.nih.gov/books/NBK190024/\" rel=\"noreferrer\">2011 report²</a> from the Institute of Medicine that tested 8 different vaccines on both adults and children showed that the vaccines are very safe.</p>\n<blockquote>\n<p>A <a href=\"http://www.jpeds.com/article/S0022-3476(13)00144-3/pdf\" rel=\"noreferrer\">2013 CDC study³</a> added to the research showing that vaccines do not cause ASD. The study looked at the number of antigens (substances in vaccines that cause the body’s immune system to produce disease-fighting antibodies) from vaccines during the first two years of life. The results showed that the total amount of antigen from vaccines received was the same between children with ASD and those that did not have ASD.</p>\n</blockquote>\n<p>The CDC has also funded many other studies on vaccine ingredients and their links to autism, especially <a href=\"http://www.cdc.gov/vaccinesafety/Concerns/thimerosal/thimerosal_faqs.html\" rel=\"noreferrer\">thimerosal⁴</a>, a mercury-based ingredient used in some vaccines. These studies have shown &quot;no link between thimerosal-containing vaccines and ASD, as well as no link between the measles, mumps, and rubella (MMR) vaccine and ASD in children.&quot;</p>\n<p><a href=\"http://www.cdc.gov/vaccinesafety/00_pdf/CDCStudiesonVaccinesandAutism.pdf\" rel=\"noreferrer\">Full list of CDC studies on the link between vaccines and autism⁵</a></p>\n<p>These are pretty convincing, but you can't just rely on one source, right?</p>\n<hr />\n<p><a href=\"http://cid.oxfordjournals.org/content/48/4/456.full\" rel=\"noreferrer\">An issue in the Oxford Journal⁶</a> also shows how even though there have been many claims that vaccines do cause autism, there aren't any studies that help support this claim.</p>\n<blockquote>\n<p>A worldwide increase in the rate of autism diagnoses—likely driven by broadened diagnostic criteria and increased awareness—has fueled concerns that an environmental exposure like vaccines might cause autism. Theories for this putative association have centered on the measles-mumps-rubella (MMR) vaccine, thimerosal, and the large number of vaccines currently administered. However, both epidemiological and biological studies fail to support these claims.</p>\n</blockquote>\n<p><a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(99)01239-8/abstract\" rel=\"noreferrer\">One study that took place in the UK from 1979-1992⁷</a> found that even though there was an increase in cases of autism, there was no jump in the amount of cases when the measles-mumps-rubella (MMR) vaccine, another controversial vaccine, was introduced in 1988.</p>\n<p><a href=\"http://pediatrics.aappublications.org/content/113/2/259.abstract?ijkey=dc1d00324fa8cd6bb885c9cb3ab0e919d0b62a53&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">A 2003 study in metropolitan Atlanta⁸</a>, Georgia compared the ages that the MMR vaccine was given in children with autism against the age that children without autism received it. The results were that the proportion of time that children were vaccinated in both control groups was similar.</p>\n<p>The Oxford Journal entry mentioned many other studies that tested the link between MMR vaccines and autism and there has been no plausible evidence.</p>\n<p>The other vaccine ingredient that is also said to cause autism is thimerosal, which I mentioned before. The Oxford Journal issue also shows studies about this link.</p>\n<p><a href=\"http://pediatrics.aappublications.org/content/112/3/604.abstract?ijkey=e453250183c05a382ba493c5ffcfbd44ed3fac79&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">A study in Finland⁹</a> helped show that there wasn't a link between thimerosal and autism. In fact, cases of autism increased in 1992 after thimerosal-containing vaccines were discontinued.</p>\n<p><a href=\"http://pediatrics.aappublications.org/content/114/3/577.abstract?ijkey=02f2f424eae1686eeaa627cd2e939a39a0bbf3b4&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">Another study in the UK¹⁰</a> also disproved the theory that thimerosal causes autism. They actually found that thimerosal-containing vaccines might even have a beneficial effect in children.</p>\n<p>There have also been many other studies that invalidate the link between thimerosal and autism.</p>\n<p>One last theory that has been proposed is that multiple vaccines being administered to a child simultaneously can weaken their immune system and cause autism. This theory is flawed for several reasons.</p>\n<p><a href=\"http://pediatrics.aappublications.org/content/109/1/124.full#sec-16\" rel=\"noreferrer\">This article¹¹</a> used data from many studies and found that vaccines do not overwhelm and weaken an infant's immune system. Infants are able to respond well to the many vaccines that are given to them.</p>\n<p><a href=\"http://archpedi.jamanetwork.com/article.aspx?articleid=515726\" rel=\"noreferrer\">Another study¹²</a> found that vaccines did not weaken the immune system to any diseases. They were unable to find consistent relationship between infectious diseases and immunization.</p>\n<hr />\n<p>All of this scientific evidence leaves one question left to be answered.</p>\n<p><strong>Why do any people believe that vaccines cause autism?</strong> (this part will get some more opinion then you may like, but it is necessary)</p>\n<p><a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(97)11096-0/abstract\" rel=\"noreferrer\">A fraudulent 1998 study¹³</a> by Andrew Wakefield and colleagues was one of the main reasons that this controversy over vaccines and autism began. It <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136032/\" rel=\"noreferrer\">used falsified data¹⁴</a> to support their claim that the MMR vaccine caused developmental problems and other autism symptoms. This study has since been retracted as it was demonstrated to be false. Dr. Wakefield, a physician in the UK, was struck off the Medical Registry due to his participation in this fraud.</p>\n<p><a href=\"http://www.webmd.com/brain/autism/searching-for-answers/vaccines-autism\" rel=\"noreferrer\">WebMD¹⁵</a> also talks about why there are still some people that believe that vaccines are the cause of autism.</p>\n<blockquote>\n<p>And when something bad happens to a child, people demand to know what or whom is to blame. &quot;Parents are clamoring for a cause,&quot; says David Tayloe, MD, a pediatrician in Greensboro, N.C., and president-elect of the American Academy of Pediatrics (AAP).</p>\n<p>&quot;It's a terrible condition. It upsets families, and it upsets me.&quot; But all the fear and anger about vaccines is misplaced, he says. &quot;There's just nothing there.&quot;</p>\n</blockquote>\n<p>It seems most people who claim that vaccines cause autism are just looking for something to blame for what is happening to children. Many parents may become angry when they find out their child has autism, and they put that anger against vaccines.</p>\n<p>There are some logical arguments that people may present, such as changing of their child's behavior after receiving vaccines. This is mostly coincidence, as most children are vaccinated around the same time autism symptoms begin to appear (usually 12-18 months)^{<a href=\"https://www.nichd.nih.gov/health/topics/autism/conditioninfo/Pages/symptoms-appear.aspx\" rel=\"noreferrer\">16</a>}. Other than this and some of the arguments mentioned earlier, there is almost no reason to believe that vaccines cause autism.</p>\n<hr />\n<p>^{[<a href=\"http://www.cdc.gov/vaccinesafety/concerns/autism/\" rel=\"noreferrer\">1</a>] <a href=\"http://www.cdc.gov/vaccinesafety/concerns/autism/\" rel=\"noreferrer\">CDC - Vaccines Do Not Cause Autism</a>}</p>\n<p>^{[<a href=\"https://www.ncbi.nlm.nih.gov/books/NBK190024/\" rel=\"noreferrer\">2</a>] <a href=\"https://www.ncbi.nlm.nih.gov/books/NBK190024/\" rel=\"noreferrer\">Adverse Effects of Vaccines: Evidence and Causality</a>}</p>\n<p>^{[<a href=\"http://www.jpeds.com/article/S0022-3476(13)00144-3/pdf\" rel=\"noreferrer\">3</a>] <a href=\"http://www.jpeds.com/article/S0022-3476(13)00144-3/pdf\" rel=\"noreferrer\">Increasing Exposure to Antibody-Stimulating Proteins and Polysaccharides in Vaccines Is Not Associated with Risk of Autism</a>}</p>\n<p>^{[<a href=\"http://www.cdc.gov/vaccinesafety/Concerns/thimerosal/thimerosal_faqs.html\" rel=\"noreferrer\">4</a>] <a href=\"http://www.cdc.gov/vaccinesafety/Concerns/thimerosal/thimerosal_faqs.html\" rel=\"noreferrer\">CDC - Frequently Asked Questions About Thimerosal</a>}</p>\n<p>^{[<a href=\"http://www.cdc.gov/vaccinesafety/00_pdf/CDCStudiesonVaccinesandAutism.pdf\" rel=\"noreferrer\">5</a>] <a href=\"http://www.cdc.gov/vaccinesafety/00_pdf/CDCStudiesonVaccinesandAutism.pdf\" rel=\"noreferrer\">CDC - Vaccines and Autism: A Summary of CDC Conducted or Sponsored Studies</a>}</p>\n<p>^{[<a href=\"http://cid.oxfordjournals.org/content/48/4/456.full\" rel=\"noreferrer\">6</a>] <a href=\"http://cid.oxfordjournals.org/content/48/4/456.full\" rel=\"noreferrer\">Vaccines and Autism: A Tale of Shifting Hypotheses</a>}</p>\n<p>^{[<a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(99)01239-8/abstract\" rel=\"noreferrer\">7</a>] <a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(99)01239-8/abstract\" rel=\"noreferrer\">Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association</a>}</p>\n<p>^{[<a href=\"http://pediatrics.aappublications.org/content/113/2/259.abstract?ijkey=dc1d00324fa8cd6bb885c9cb3ab0e919d0b62a53&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">8</a>] <a href=\"http://pediatrics.aappublications.org/content/113/2/259.abstract?ijkey=dc1d00324fa8cd6bb885c9cb3ab0e919d0b62a53&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">Age at First Measles-Mumps-Rubella Vaccination in Children With Autism and School-Matched Control Subjects: A Population-Based Study in Metropolitan Atlanta</a>}</p>\n<p>^{[<a href=\"http://pediatrics.aappublications.org/content/112/3/604.abstract?ijkey=e453250183c05a382ba493c5ffcfbd44ed3fac79&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">9</a>] <a href=\"http://pediatrics.aappublications.org/content/112/3/604.abstract?ijkey=e453250183c05a382ba493c5ffcfbd44ed3fac79&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">Thimerosal and the Occurrence of Autism: Negative Ecological Evidence From Danish Population-Based Data</a>}</p>\n<p>^{[<a href=\"http://pediatrics.aappublications.org/content/114/3/577.abstract?ijkey=02f2f424eae1686eeaa627cd2e939a39a0bbf3b4&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">10</a>] <a href=\"http://pediatrics.aappublications.org/content/114/3/577.abstract?ijkey=02f2f424eae1686eeaa627cd2e939a39a0bbf3b4&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">Thimerosal Exposure in Infants and Developmental Disorders: A Prospective Cohort Study in the United Kingdom Does Not Support a Causal Association</a>}</p>\n<p>^{[<a href=\"http://pediatrics.aappublications.org/content/109/1/124.full#sec-16\" rel=\"noreferrer\">11</a>] <a href=\"http://pediatrics.aappublications.org/content/109/1/124.full#sec-16\" rel=\"noreferrer\">Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?</a>}</p>\n<p>^{[<a href=\"http://archpedi.jamanetwork.com/article.aspx?articleid=515726\" rel=\"noreferrer\">12</a>] <a href=\"http://archpedi.jamanetwork.com/article.aspx?articleid=515726\" rel=\"noreferrer\">DTP Immunization and Susceptibility to Infectious Diseases</a>}</p>\n<p>^{[<a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(97)11096-0/abstract\" rel=\"noreferrer\">13</a>] <a href=\"http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(97)11096-0/abstract\" rel=\"noreferrer\">RETRACTED: Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children</a>}</p>\n<p>^{[<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136032/\" rel=\"noreferrer\">14</a>] <a href=\"http://www.webmd.com/brain/autism/searching-for-answers/vaccines-autism\" rel=\"noreferrer\">The MMR vaccine and autism: Sensation, refutation, retraction, and fraud</a>}</p>\n<p>^{[<a href=\"http://www.webmd.com/brain/autism/searching-for-answers/vaccines-autism\" rel=\"noreferrer\">15</a>] <a href=\"http://www.webmd.com/brain/autism/searching-for-answers/vaccines-autism\" rel=\"noreferrer\">WebMD - Autism-Vaccine Link: Evidence Doesn't Dispel Doubts</a>}</p>\n<p>^{[<a href=\"https://www.nichd.nih.gov/health/topics/autism/conditioninfo/Pages/symptoms-appear.aspx\" rel=\"noreferrer\">16</a>] <a href=\"https://www.nichd.nih.gov/health/topics/autism/conditioninfo/Pages/symptoms-appear.aspx\" rel=\"noreferrer\">When do children usually show symptoms of autism spectrum disorder (ASD)?</a>}</p>\n", "score": 60 }, { "answer_id": 565, "body": "<p>You have already gotten an excellent answer on the scientific evidence for the autism-vaccination link (namely, that there isn't one). I would however like to address this part of your question directly, as an academic epidemiologist:</p>\n\n<blockquote>\n <p>Could there be a conspiracy in the pharmaceutical industry to cover up\n a link?</p>\n</blockquote>\n\n<p>No.</p>\n\n<p>It is a relatively common tactic in the various denial communities (vaccines, HIV, climate change, etc.) to posit that a major conspiracy exists to hide the truth, and thus explain away the utter lack of evidence for their position. But one should consider what that kind of conspiracy would actually entail.</p>\n\n<p>First, a number of researchers into vaccine safety are <em>not</em> paid by pharmaceutical companies. Which means they don't particularly have any financial incentive to play along.</p>\n\n<p>Second, some of the scientific evidence for the lack of a link between autism and vaccines emerges from birth cohorts in countries with a national health registry, <a href=\"http://archpedi.jamanetwork.com/article.aspx?articleid=1919642#Results\">such as this study</a>. The authors report no pharmaceutical funding (nor would they need it for a registry study), so for this study a conspiracy would not only have to involve researchers who are not compensated, but the suborning of an entire national health registry.</p>\n\n<p>Finally, even absent financial incentives, a conspiracy to hide the truth is actively counter to the incentives that researchers <em>do</em> have. Null results, like \"nope, vaccines still not associated with autism...\" are not exactly amazing results. Controversial ideas that turn out to be true, like the link between HPV and cancer, even if they're an uphill battle, win people <a href=\"https://www.vch.ca/media/public_health_nobel_winning_hpv.pdf\">Nobel Prizes</a>. Actually figuring out the causal mechanism of autism? That's a potentially career changing result. Getting an entire <em>field</em> and the healthcare systems of entire countries to take a pass in favor of pharmaceutical profits that those researchers don't get a share in? That's well outside the realm of possibility.</p>\n", "score": 29 }, { "answer_id": 15728, "body": "<p>Perhaps the question should be asked, <strong><em>can vaccines prevent autism?</em></strong></p>\n\n<blockquote>\n <p>One fact of note is that postnatal infections with the vaccine-targeted infectious agents, including measles, mumps, and rubella, are not known to cause autism, although autistic features have been reported in children with congenital rubella syndrome (Chess, 1971); one study reported the use of mathematical modeling and epidemiological data to conclude that MMR immunization had been associated with prevention of substantial numbers of cases of congenital rubella syndrome and associated autism in the period 2001–2010 in the United States (Berger et al., 2011). </p>\n</blockquote>\n\n<p><em>Adverse Effects of Vaccines: Evidence and Causality.</em> <a href=\"https://www.ncbi.nlm.nih.gov/books/NBK190017/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/books/NBK190017/</a></p>\n", "score": 11 } ]

[ "vaccination", "autism" ]

[ { "answer_id": 736, "body": "<p>Most dentists - for <em>most</em> procedures - aim for a <em>painless</em> experience. If there is reason to keep some pain sensation intact, the dentist will inform you, and ask at appropriate intervals if you can feel pain.</p>\n\n<p>The efficacy of lidocaine and other local anesthetics depends on how closely your nerve distribution comes to the norm (they will inject the environs of the \"normal\" anatomical position of the nerve), how much anesthetic is injected, whether there are local factors which alter the local tissue pH (e.g. presence of an abscess or infection), how quickly it is removed from the site, etc.</p>\n\n<blockquote>\n <p>Is this feedback that the dentist can use to detect issues with the actual work as he goes along, or would the only purpose of reporting it be to try to get him to do something to mitigate it, for the sake of my immediate experience?</p>\n</blockquote>\n\n<p>Local anesthetics prevent pain sensation, but not vibration or pressure, which themselves can be unpleasant. Hypothetically, a dental procedure which should be painless with anesthesia can be carried out equally well whether the patient feels pain or not, so if you are stoic, feeling pain and not telling your dentist will not likely affect the outcome of that procedure. However, informing the dentist helps them to know if your anatomy is different (valuable information for the next time they need to do a similar local or regional block, your response to the anesthetic used (they might try another anesthetic or approach in the future), or if there might be an unseen infection altering the pH (and efficacy) of the anesthetic. Therefore it is probably wise to let your dentist know what you're feeling. They can reassess the situation, then offer you relief of some kind: a painless injection (the second injection into an already partially anesthetized region is truly painless), nitrous oxide (a gas), or other.</p>\n\n<p>I would liken this for most instances to suturing a laceration. There is <em>never</em> a time when I wish the patient to feel pain while I'm addressing the repair. I address what I see. If a patient feels pain, I want to know that and address the situation.</p>\n\n<p>_{<a href=\"http://www.cda-adc.ca/jcda/vol-68/issue-9/546.pdf\">An Update on Local Anesthetics in Dentistry</a>} </p>\n", "score": 33 }, { "answer_id": 1569, "body": "<p>It can absolutely give the dentist information which will help him identity potential problems. I recently had a root canal. It was a two-visit procedure, and on the first day, he drilled out the nerve fibers, tissue, and pulp, then placed a temporary crown over the tooth. </p>\n\n<p>The second visit was supposed to be a simple matter of removing the temporary crown, filling the tooth, and inserting the permanent crown. When he began to work, it was quite painful. He was shocked, and immediately set about trying to determine the cause of the problem. </p>\n\n<p>He spotted a bit of nerve fiber he had missed the first time, then completed the procedure. </p>\n\n<p>In this case, the fact I was even able to feel pain was an indication that he had overlooked something earlier in the process. If I hadn't told him about the pain, another procedure would have been necessary.</p>\n", "score": 8 } ]

[ "pain", "dentistry" ]

[ { "answer_id": 1278, "body": "<p>Great question! I think it's answerable as an overview, but please know this is only the tip of the iceberg.*</p>\n\n<p><strong>Summary</strong>: Yes, we have deficits of certain blood products in certain locations at certain times that affect patient care. However, a small percentage of blood product does expire unused (because it wasn't the <em>right</em> product [see background] in the <em>right</em> place at the <em>right</em> time).</p>\n\n<p><strong>A little background</strong> </p>\n\n<p>Donated blood is not usually transfused into a patient as whole blood. Instead, it's broken down into several components which are transfused in different clinical scenarios. The issues of storage and supply are different for each component. The components are:</p>\n\n<ul>\n<li>Plasma, and derivatives</li>\n<li>Red Blood Cells (RBCs)</li>\n<li>Platelets</li>\n<li>Granulocytes (rarely transfused)</li>\n</ul>\n\n<p>These different components require different storage conditions, so they are separated as soon as possible after donation.</p>\n\n<p><strong>OP's first question</strong>:</p>\n\n<blockquote>\n <p>First, do we ever have a blood deficit, situations where someone who could have been saved in a hospital dies because there wasn't blood to treat them?</p>\n</blockquote>\n\n<p>Yes. Well, actually your question is impossible to answer. :-) We could never know whether someone could-have-been-saved with a transfusion nor whether someone who received a transfusion would-have-died. Those are hypothetical constructs that are interesting to think about but are not compatible with research. </p>\n\n<p>However, we <em>can</em> ask whether there is evidence that blood supply on a clinical level is limited, for instance: </p>\n\n<ul>\n<li>doctors are requesting products that aren't available for patients; </li>\n<li>doctors are requesting fewer products than they think would be ideal for a particular patient because of a blood bank shortage; </li>\n<li>elective surgeries are being postponed; or </li>\n<li>blood banks are substituting products that may have a slightly increased risk of complications due to less-than-ideal immune compatibility.</li>\n</ul>\n\n<p>All of these are more nuanced than they seem, but to some degree all do occur. </p>\n\n<p>Quoting from a <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=17465938\">paper in the journal Transfusion entitled <em>How do I manage a blood shortage in a transfusion service?</em></a>:</p>\n\n<blockquote>\n <p>Although there are more than 16 million blood donations per year provided to more than 4 million recipients, blood shortages have recurred for decades [...] twice every year. Anyone with any experience at blood centers or transfusion services is quite accustomed to these expected shortages.</p>\n</blockquote>\n\n<p>He further notes that this problem is likely to worsen because the requirement for transfusions (all types) is increasing at a rate of 5-7% per year while donations are not matching that increase.</p>\n\n<p>The first thing that happens when there is a blood bank shortage usually involves the Transfusion Medicine specialist in the blood bank having a conversation with every doctor who orders the blood product that is limited. Together they determine whether a smaller amount of product or a deferment in transfusion might be clinically appropriate/acceptable. </p>\n\n<p>The distinction between those last two words &mdash; <code>appropriate|accetable</code> &mdash; is the key to whether clinical care is actually being compromised. In many cases, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/26019707\">clinicians indeed are requesting product beyond what is recommended in published guidelines</a>, because they feel that the patient's condition warrants it due to some special circumstance. It seems likely that at least a small percentage of the time, the clinician was right, but this can never be proven.</p>\n\n<p>It is also the case that <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf\">elective surgeries are sometimes postponed for this reason</a> (see chart 8-1, p 43), although it's rare. </p>\n\n<p><strong>Another question</strong></p>\n\n<blockquote>\n <p>Related, if we don't run a deficit then what happens to my excess blood?... is it used for medical research?</p>\n</blockquote>\n\n<p>Although localized shortages of particular products do occur and are disruptive, it is true that a small percentage of the products expire unused. In the U.S., this was estimated at 14% of supply in 1989 and had fallen to 5.2% in 2011, per <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf\">a report from the US Dept Health and Human Services</a>, the most recent data available I've found. These are complicated and nuanced data that this format does not allow complete explanation of (and I myself am not completely familiar with), but please read <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf\">the linked HHS report</a> if interested.</p>\n\n<p>As for what happens to the excess - it's probably discarded, although I can't prove that. Regarding your question about research: In addition to being sub-optimal because it's old, the blood was originally collected from human donors. Such research would be subjected to IRB requirements for protection of human subjects. This would likely require researchers to obtain permission from donors (/subjects) at the time of donation to use the product for research. This may happen in localized settings, but I know of no large-scale project.</p>\n\n<hr>\n\n<p>_{\n* I limit this discussion to the U.S. While I realize the weaknesses &mdash; inadequacy, really &mdash; of that approach, this is the healthcare system where I was able to locate data, the O.P. is apparently asking about the U.S. situation (Red Cross), and I am most familiar with the clinical situation here. If another answer can offer a more global perspective, please do.\n}</p>\n", "score": 31 } ]

[ "blood" ]

[ { "answer_id": 138, "body": "<p>In short, and according to <a href=\"http://healthysleep.med.harvard.edu/healthy/about\">the WGBH Educational Foundation and the Harvard Medical School Division of Sleep Medicine</a>:</p>\n\n<ul>\n<li><p>Lack of sleep can, in the short term, \"affect judgment, mood, ability to learn and retain information, and may increase the risk of serious accidents and injury\"</p></li>\n<li><p>In the long term, it may \"lead to a host of health problems including obesity, diabetes, cardiovascular disease, and even early mortality\". (We are speaking about an actual sleep deprivation here)</p></li>\n</ul>\n\n<p>They have published a complete set of articles about that, <a href=\"http://healthysleep.med.harvard.edu/healthy/matters/consequences\">the entry point is here</a>.</p>\n", "score": 28 }, { "answer_id": 332, "body": "<p>I would also add that if you're consistently getting 4-5 hours of sleep (instead of about 8) then it's counterproductive for studying. Aside from affecting your ability to concentrate, there's also the effect on memory, especially memory consolidation for instance. </p>\n\n<p>As a grad student, I know that it's a constant challenge balancing sleep and studying, but I would still urge you to consider this.</p>\n\n<p>See a review here for example</p>\n\n<p>Rasch, Björn and Jan Born. <a href=\"http://physrev.physiology.org/content/93/2/681\">About Sleep's Role in Memory.</a> Physiol Rev. 2013 Apr; 93(2): 681–766.\ndoi: 10.1152/physrev.00032.2012</p>\n", "score": 15 } ]

[ "sleep" ]

[ { "answer_id": 20980, "body": "<p>The definition of mortality rate that you've given does not match any practical definition I'm familiar with.*</p>\n\n<p>When people talk about the mortality rate of a disease, what they <em>usually</em> mean is the <a href=\"https://en.wikipedia.org/wiki/Case_fatality_rate\" rel=\"noreferrer\">case fatality rate</a> or the <a href=\"https://www.cdc.gov/csels/dsepd/ss1978/lesson3/section3.html\" rel=\"noreferrer\">death-to-case ratio</a>, which is simply defined as <em>N</em>_d / <em>N</em>_i, where <em>N</em>_d is the number of deaths attributed to the disease over a given time period and <em>N</em>_i is the total number of new cases of the disease observed during the same time period. By this definition, the current case fatality rate of 2019-nCov according to your quoted figures is 362 / 17491 ≈ 2.07%.</p>\n\n<p>(The <a href=\"https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6\" rel=\"noreferrer\">tracker</a> seems to have been updated since you asked your question, and now lists a total of 20679 confirmed cases and 427 deaths, for a CFR of 427 / 20679 ≈ 2.06%.)</p>\n\n<p>^{*) As a theoretical definition of the mortality rate <em>in the long run</em>, when all infected patients have either died or recovered, it can sort of make sense. But then it becomes equivalent to the usual definition of the case fatality rate.}</p>\n\n<hr>\n\n<p>To compare this with your definition of \"mortality rate\" (as <em>N</em>_d / (<em>N</em>_d + <em>N</em>_r), where <em>N</em>_r is the number of individuals who have recovered from the disease), we need to start by observing that there's no single universal and unambiguous definition of what \"recovering from a disease\" means. Commonly used definitions tend to be something like \"no symptoms for <em>X</em> days\" and/or \"viral load below <em>N</em> particles per mL for <em>X</em> days\" or simply \"whenever a doctor declares that you're healthy again and lets you out of the hospital\".</p>\n\n<p>Now, let's say that we're using a (somewhat) objective definition of recovery like \"no detectable symptoms for two days\". The first observation is that any epidemic first observed less than two days ago would, according to your definition, inevitably have a mortality rate of 100% simply because none of the people infected so far would have had time to be considered definitely recovered yet. (That is assuming that at least one person had died from the infection; otherwise both the numerator and the denominator would be zero, and the rate thus undefined.)</p>\n\n<p>Further, even after some of the earliest cases have been symptom-free long enough to be counted as recovered, your definition would still yield a highly upwards biased estimate of the \"true\" long-term fatality rate during the early phase of the epidemic, when the number of new cases per day is still increasing. This is because, for most infectious diseases, any deaths typically occur when the disease is at its most severe state, whereas those who survive the disease will then experience a gradual decline in symptoms as their immune system succeeds in halting and reversing the progress of the infection.</p>\n\n<hr>\n\n<p>For an illustrative example, let's consider a hypothetical disease with a theoretical 1% long-term average CFR — that is to say, exactly 1% of all (recognizably) infected patients will die of the disease. Let's further assume that this disease typically takes two days to progress from the initial onset of recognizable symptoms to the state of maximum severity, which is when most of the deaths occur. After this, assuming that the patient survives, the symptoms gradually decline over the following three days. As remission is possible (but rare), doctors will generally consider a patient recovered only after showing no symptoms for at least two days. Thus, a typical case would progress as follows:</p>\n\n<blockquote>\n <p>onset of symptoms → increasing symptoms (2 days) → peak severity → declining symptoms (3 days) → no symptoms → observation (2 days) → officially recovered (total time: approx. 7 days from onset)</p>\n</blockquote>\n\n<p>or, for the 1% of patients for whom the disease is fatal:</p>\n\n<blockquote>\n <p>onset of symptoms → increasing symptoms (2 days) → death (total time: approx. 2 days from onset)</p>\n</blockquote>\n\n<p>Now, let's assume that, during the early period of an epidemic when the infection is still spreading exponentially, the number of new cases increases by a factor of 10 every three days. Thus, during this period, the number of new cases, recoveries and deaths per day might grow approximately as follows (assuming for the sake of the example that exactly 1%, rounded down, of the patients diagnosed on each day will die two days later):</p>\n\n<pre><code> | cases | recovered | deaths | | | \nday | new | total | new | total | new | total | Nd / Ni | Nd/(Nd+Nr) |\n----+-------+-------+-------+-------+-------+-------+---------+------------+\n 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 2 | 2 | 3 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 3 | 5 | 8 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 4 | 10 | 18 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 5 | 20 | 38 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 6 | 50 | 88 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 7 | 100 | 188 | 0 | 0 | 0 | 0 | 0.00% | N/A |\n 8 | 200 | 388 | 1 | 1 | 0 | 0 | 0.00% | 0.0% |\n 9 | 500 | 888 | 2 | 3 | 1 | 1 | 0.11% | 25.0% |\n 10 | 1000 | 1888 | 5 | 8 | 2 | 3 | 0.16% | 27.3% |\n 11 | 2000 | 3888 | 10 | 18 | 5 | 8 | 0.21% | 30.8% |\n 12 | 5000 | 8888 | 20 | 38 | 10 | 18 | 0.20% | 32.1% |\n</code></pre>\n\n<p>As you can see from the table above, naïvely calculating the case fatality rate as (total number of deaths) / (total number of cases) during this exponential growth period does underestimate the true long-term CFR by a factor of (in this case) about 5 due to the two-day lag time between infection and death. On the other hand, using your formula of (total deaths) / (total deaths + recovered) would <em>overestimate</em> the true CFR by a factor of about 30!</p>\n\n<p>Meanwhile, let's assume that, after the first 12 days, the growth of the epidemic saturates at 10,000 new cases per day. Now the total numbers will look like this:</p>\n\n<pre><code> | cases | recovered | deaths | | | \nday | new | total | new | total | new | total | Nd / Ni | Nd/(Nd+Nr) |\n----+-------+-------+-------+-------+-------+-------+---------+------------+\n 13 | 10000 | 18888 | 50 | 88 | 20 | 38 | 0.20% | 30.2% |\n 14 | 10000 | 28888 | 99 | 187 | 50 | 88 | 0.30% | 32.0% |\n 15 | 10000 | 38888 | 198 | 385 | 100 | 188 | 0.48% | 32.8% |\n 16 | 10000 | 48888 | 495 | 880 | 100 | 288 | 0.59% | 24.7% |\n 17 | 10000 | 58888 | 990 | 1870 | 100 | 388 | 0.66% | 17.2% |\n 18 | 10000 | 68888 | 1980 | 3850 | 100 | 488 | 0.71% | 11.2% |\n 19 | 10000 | 78888 | 4950 | 8800 | 100 | 588 | 0.74% | 6.3% |\n 20 | 10000 | 88888 | 9900 | 18700 | 100 | 688 | 0.77% | 3.5% |\n 21 | 10000 | 98888 | 9900 | 28600 | 100 | 788 | 0.80% | 2.7% |\n</code></pre>\n\n<p>As you can see, the two measures of mortality rate do eventually start converging as the growth of the epidemic slows down. In fact, in the long run, as the majority of patients either recover or die, they do both end up converging to the \"true\" long-term case fatality rate of 1%. But by then, the epidemic will be basically over.</p>\n\n<p>There are various ways to obtain a more accurate estimate of the long-term fatality rate even during the early exponential growth phase of an epidemic. One such method would be to look at the outcomes of a single cohort of patients diagnosed at the same time. For our hypothetical example epidemic, looking e.g. at just the 1000 patients diagnosed on day 10, we could get an accurate estimate of the CFR by day 12 simply by dividing the 10 deaths <em>within that cohort</em> by the total number of patients in the cohort. Furthermore, observing multiple cohorts would give us a pretty good idea of how long after diagnosis we would need to wait before the estimated case fatality rate for each cohort gets close to its final true value.</p>\n\n<p>Unfortunately carrying out this kind of cohort analysis for 2019-nCov would require more detailed information than the tracker you've linked to provides. Even the <a href=\"https://docs.google.com/spreadsheets/d/1UF2pSkFTURko2OvfHWWlFpDFAr1UxCBA4JLwlSP6KFo/edit?usp=sharing\" rel=\"noreferrer\">time series spreadsheet</a> the tracker links to doesn't directly provide such detailed cohort data, although it might be possible to obtain better estimates from it by making some more or less reasonable assumptions about the typical progress of the disease.</p>\n\n<hr>\n\n<p><strong>Addendum:</strong> A few preliminary cohort studies of the kind I describe above do appear to have already been published for 2019-nCoV.</p>\n\n<p>In particular, <a href=\"https://doi.org/10.1016/S0140-6736(20)30185-9\" rel=\"noreferrer\">\"A novel coronavirus outbreak of global health concern\"</a> by Wang <em>et al.</em> and <a href=\"https://doi.org/10.1016/S0140-6736(20)30183-5\" rel=\"noreferrer\">\"Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China\"</a> by Huang <em>et al.</em>, both published on January 24 in <em>The Lancet</em>, note that, out of the first 41 patients diagnosed with 2019-nCoV before Jan 2, 2020 in Wuhan, six had died (and 28 had been discharged, leaving seven hospitalized) by Jan 22, giving a case fatality rate of 14.6% in this cohort.</p>\n\n<p>However, they do advise treating this figure with due caution, noting a number of reasons (besides just the small number of cases examined) why it may not fully reflect the eventual long-term CFR:</p>\n\n<blockquote>\n <p>\"<em>However, both of these</em> [CFR] <em>estimates</em> [of 14.6% from the 41 patient cohort and of 2.9% from all 835 cases confirmed at the time of writing] <em>should be treated with great caution because not all patients have concluded their illness (ie, recovered or died) and the true number of infections and full disease spectrum are unknown. Importantly, in emerging viral infection outbreaks the case-fatality ratio is often overestimated in the early stages because case detection is highly biased towards the more severe cases. As further data on the spectrum of mild or asymptomatic infection becomes available, one case of which was documented by Chan and colleagues, the case-fatality ratio is likely to decrease.</em>\"</p>\n</blockquote>\n\n<p>There's also a later paper titled <a href=\"https://doi.org/10.1016/S0140-6736(20)30211-7\" rel=\"noreferrer\">\"Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study\"</a> by Chen <em>et al.</em>, published on Jan 30, that examines a cohort of 99 patients diagnosed between Jan 1 to Jan 20 and reports a CFR of 11% within this cohort. However, the study only followed these patients up to Jan 25, by which time more than half of them (57 out of 99) still remained hospitalized.</p>\n", "score": 47 }, { "answer_id": 20972, "body": "<p>The equation you use for mortality is only really useful in the very long term for a known disease, when most cases have resolved.</p>\n\n<p>It's not very informative in the short-term, when the vast majority of total cases are neither deaths nor recoveries.</p>\n\n<p>Right now, the vast majority of people diagnosed have a mild illness and are very unlikely to die, but it takes a long time for them to be considered in the \"recovered\" category. Additionally, many of those who have died are particularly vulnerable. From WHO:</p>\n\n<blockquote>\n <p>As with other respiratory illnesses, infection with 2019-nCoV can cause mild symptoms including a runny nose, sore throat, cough, and fever. It can be more severe for some persons and can lead to pneumonia or breathing difficulties. More rarely, the disease can be fatal. Older people, and people with pre-existing medical conditions (such as, diabetes and heart disease) appear to be more vulnerable to becoming severely ill with the virus.</p>\n</blockquote>\n\n<p>Estimates for mortality that you see in the news might instead be based on deaths/cases, or are based on expert comparisons to past epidemic coronavirus strains and knowledge of the typical course of the illness.</p>\n\n<p>Additionally, we don't know how accurate the numbers are, especially for cases. There may be many more mild cases that go unreported.</p>\n\n<p>There won't be good estimates of the actual mortality rate until more time has passed, and even in that case it is unlikely that a single number will be very informative. Instead, the risk will vary by age and other factors. Good sources for information, like the WHO, don't report mortality rates: they are only reporting cases and deaths at this time.</p>\n\n<p>Some good sources for further information:</p>\n\n<p><a href=\"https://www.who.int/emergencies/diseases/novel-coronavirus-2019\" rel=\"noreferrer\">https://www.who.int/emergencies/diseases/novel-coronavirus-2019</a></p>\n\n<p><a href=\"https://www.cdc.gov/coronavirus/2019-nCoV/summary.html\" rel=\"noreferrer\">https://www.cdc.gov/coronavirus/2019-nCoV/summary.html</a></p>\n\n<p><a href=\"https://www.nhs.uk/conditions/wuhan-novel-coronavirus/\" rel=\"noreferrer\">https://www.nhs.uk/conditions/wuhan-novel-coronavirus/</a></p>\n", "score": 20 }, { "answer_id": 20977, "body": "<p>I'd like to chime in with an explanation of <em>what exactly</em> is wrong with the calculation offered in the question, rather than just saying \"it's a wrong formula\". Understanding the \"whys\" of the fallacy is important. So I'll try to answer your question from the math point of view.</p>\n\n<p><strong>TL;DR: The root cause of the fallacy is that recovery takes much longer that death.</strong></p>\n\n<blockquote>\n <p><code>(Nd / (Nd + Nr)) * 100 = 41%</code><br>\n where: Nd is the total number of deaths,<br>\n Nr is the total number of full recoveries.</p>\n</blockquote>\n\n<p>That formula (and the logic behind it) is correct as long as <code>Nd</code> and <code>Nr</code> both refer to <strong>the same fixed group of people</strong>. That is, if we had picked <code>N</code> infected people, waited for them <em>all</em> to reach the final state (recovery or death), and put those <code>Nr</code> and <code>Nd</code> to that formula above - then yes, it would give the statistical mortality rate in that group.</p>\n\n<p>However, the current counts of recovery/death outcomes do not refer to <em>the same group</em>. <code>Nd</code> in each WHO report refers to the group of all people infected thus far since the start of the outbreak. But the final outcome of <em>all</em> people in that group is yet unknown. Daily <code>Nr</code> refers only to a subgroup of all those infected (excluding those unknowns), see? So you can't take <code>Nd</code> and <code>Nr</code> from a WHO report and put those numbers to that formula - that would be apples and oranges...</p>\n\n<p>To illustrate this point, consider a grossly simplified imaginary situation:<br>\nthere's a disease which may lead to death on the 3rd day, while the rest of infected people will fully recover on the 15th day. In that case, <code>Nd</code> in the official report would encompass all people infected 3 days ago and before, while <code>Nr</code> would encompass all people infected 15 days ago and before. Given the high flow of new confirmed cases coming each day, the difference between those two groups is huge: it is all those people infected in 12 days!</p>\n\n<p>In our real case that difference is far greater than <code>Nr</code> and <code>Nd</code> combined, which means the error from ignoring that difference renders the calculation totally useless. (Well, it's useful as an absolute upper limit, but no more).</p>\n", "score": 14 }, { "answer_id": 21002, "body": "<p>According to earlier answers, in this early phase of 2019-nCoV, Nd/(Nd+Nr) is an overestimator, and Nd/Nc is an underestimator. </p>\n\n<p>Since the currently bantered about rate matches the underwestimator Nd/Nc, you are correct that 2019-nCoV is more 'dangerous' than commonly claimed. I used quotes because dangerous a squirmy term.</p>\n\n<p>Noting that Nd/Nc equals Nd/(Nd+Nr) after the epidemic is over, a better estimate would be to track the two quotients over time, and extrapolate their curves to the point they meet. That would still be a biased estimator, but less so than either on it's own. I'm guessing there are more sophisticated estimators with less bias, and I've posted that question here:</p>\n\n<p><a href=\"https://medicalsciences.stackexchange.com/questions/21001/what-is-a-sophisticated-estimate-of-the-2019-ncov-fatality-rate\">What is a sophisticated estimate of the 2019-nCoV fatality rate?</a></p>\n", "score": 4 }, { "answer_id": 21771, "body": "<p>I understand what you're trying/hoping to do here, but the correction method you try to apply is unsuitable. You need to explicitly account for the time delays to deaths <em>and</em> consider a confined population of cases <em>or</em> try to infer from a closed sample a correction factor to apply to the open-ended/ongoing epidemic. Such a study was recently <a href=\"https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.12.2000256\" rel=\"nofollow noreferrer\">published</a> <em>based</em> on the Diamond Princess (cruise ship) cases, using the information collected therein to correct (in this paper) the data on China.</p>\n\n<blockquote>\n <p>In real time, estimates of the case fatality ratio (CFR) and infection fatality ratio (IFR) can be biased upwards by under-reporting of cases and downwards by failure to account for the delay from confirmation to death. Collecting detailed epidemiological information from a closed population such as the quarantined Diamond Princess cruise ship in Japan can produce a more comprehensive description of asymptomatic and symptomatic cases and their subsequent outcomes. Our aim was to estimate the IFR and CFR of coronavirus disease (COVID-19) in China, using data from passengers of the Diamond Princess while correcting for delays between confirmation and death and for the age structure of the population.</p>\n</blockquote>\n\n<p><a href=\"https://i.stack.imgur.com/mOofi.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/mOofi.png\" alt=\"enter image description here\"></a></p>\n\n<blockquote>\n <p>During an outbreak, the so-called naive CFR (nCFR), i.e. the ratio of reported deaths date to reported cases to date, will underestimate the true CFR because the outcome (recovery or death) is not known for all cases, assuming all cases are detected. We can estimate the true denominator for the CFR (i.e. the number of cases with known outcomes) by accounting for the delay from confirmation to death. We assumed that the delay from confirmation to death followed the same distribution as the estimated time from hospitalisation to death, based on data from the COVID-19 outbreak in Wuhan, China, between 17 December 2019 and 22 January 2020, accounting for underestimation in the data as a result of as-yet-unknown disease outcomes [...]</p>\n \n <p>To adjust the CFR to account for delay to outcome, we use the method developed in <a href=\"https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0006852\" rel=\"nofollow noreferrer\">Nishiura et. al (2009)</a> where case and death incidence data are used to estimate the number of cases with known outcomes, i.e. cases where the resolution, death or recovery, is known to have occurred:</p>\n</blockquote>\n\n<p><a href=\"https://i.stack.imgur.com/fdGoq.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/fdGoq.png\" alt=\"enter image description here\"></a></p>\n\n<blockquote>\n <p>where <em>c_t</em> is the daily case incidence at time <em>t</em>, (with time measured in calendar days), <em>f_t</em> is the proportion of cases with delay <em>t</em> between onset or hospitalisation and death; <em>u_t</em> represents the underestimation of the known outcomes and is used to scale the value of the cumulative number of cases in the denominator in the calculation of the cCFR. Given that asymptomatic infections are typically not reported, especially during an ongoing outbreak of a novel infection, this correction is normally used to calculate the cCFR. However, because of the high level of testing on the cruise ship, we were able to use this correction to calculate the corrected IFR (cIFR). After that, we used the measured proportions of asymptomatic to symptomatic cases on the Diamond Princess to scale the cIFR to estimate the cCFR. [...]</p>\n \n <p><strong>We estimated that the all-age cIFR on the Diamond Princess was 1.3% (95% confidence interval (CI): 0.38–3.6) and the cCFR was 2.6% (95% CI: 0.89–6.7).</strong> However, as the age distribution on the ship was skewed towards older individuals (mean age: 58 years), we also report age-stratified estimates. Using the age distribution of cases and deaths on the ship to estimate for only individuals 70 years and older, the cIFR was 6.4% (95% CI: 2.6–13) and the cCFR was 13% (95% CI: 5.2–26). The 95% CI were calculated with an exact binomial test, with death count and either cases or known outcomes (depending on whether it was an interval for the naive or corrected estimate).</p>\n \n <p>Using an approach similar to <a href=\"https://projecteuclid.org/download/pdfview_1/euclid.ss/1421330546\" rel=\"nofollow noreferrer\">indirect standardisation</a>, we used the age-stratified nCFR estimates reported in a large study in China to calculate the expected number of deaths of people on board the ship in each age group, (assuming this nCFR estimate in the standard population was accurate). This produced a total of 15.15 expected deaths, which corresponds to a nCFR estimate of 5% (15.15/301) for the Diamond Princess, which falls within the top end of our 95% CI. As our cCFR for Diamond Princess was 2.6% (95% CI: 0.89–6.7), this suggests we need to multiply the nCFR estimates in China by a factor 52% (95% CI: 14–100) to obtain the correct value. <strong>As the raw overall nCFR reported in the data from China was 2.3%, this suggests the cCFR in China during that period was 1.2% (95% CI: 0.3–3.1) and the IFR was 0.6% (95% CI: 0.2–1.7)</strong>. Based on cases and deaths reported in China up to 4 March 2020, the nCFR calculation was considerably higher than the cCFR we estimate here (based on data taken from [8], nCFR = 2,984/80,422 = 3.71% (95% CI: 3.58–3.84)). The confidence intervals calculated for China using an indirect standardisation method reflect the uncertainty in the Diamond Princess estimates, as it is carried forward in the scaling.</p>\n</blockquote>\n\n<p>As you can see, if one does this correction properly, the \"death rate\" (cCFR) for Covid-19 is actually lower (than the nCFR).</p>\n\n<p>If the above is too dense/technical of an explanation, the <em>Nature</em> news <a href=\"https://www.nature.com/articles/d41586-020-00885-w\" rel=\"nofollow noreferrer\">coverage of it</a>:</p>\n\n<blockquote>\n <p>Another team used data from the ship to estimate that the proportion of deaths among confirmed cases in China, the case fatality rate (CFR), was around 1.1% — much lower than the 3.8% estimated by the World Health Organization (WHO).</p>\n \n <p><strong>The WHO simply divided China’s total number of deaths by the total number of confirmed infections</strong>, says Timothy Russell, a mathematical epidemiologist at the London School of Hygiene and Tropical Medicine. <strong>That method does not take into account that only a fraction of infected people are actually tested, and so it makes the disease seem more deadly than it is</strong>, he says.</p>\n \n <p>By contrast, Russell and his colleagues used data from the ship — where almost everyone was tested, and all seven deaths recorded — and combined it with more than 72,000 confirmed cases in China, making their CFR estimate more robust. [...]</p>\n \n <p>The group also estimates that the infection fatality rate (IFR) in China — the proportion of all infections, including asymptomatic ones, that result in death — is even lower, at roughly 0.5%. The IFR is especially tricky to calculate in the population, because some deaths go undetected if the person didn’t show symptoms or get tested.</p>\n</blockquote>\n\n<p>(Nature news says the [latter] paper had not been peer-reviewed/published, but in the meantime it has been published by <em>Eurosurveillance</em>, the same journal that had published the 1st Diamond Princess paper.)</p>\n\n<p>I should also noted that an 8th death was reported <a href=\"https://www.ship-technology.com/news/covid-19-diamond-princess-cruise-ship-eighth-death/\" rel=\"nofollow noreferrer\">much later</a> (March 20) in relation to the Diamond Princess. It probably doesn't substantially change the conclusions of that paper (which included only the 7 reported deaths you see in the graph.)</p>\n", "score": 1 } ]

[ "virus", "infectious-diseases", "death", "covid-19" ]

[ { "answer_id": 447, "body": "<p>Alcohol is a psychoactive drug that acts as a central nervous system depressant.</p>\n\n<p>Drinking under-age increases alcohol risks in later life. Research shows the brain keeps developing well into the twenties, during which time it continues to establish important communication connections and further refines its function and studies show that young people who drink heavily may put themselves at risk for a range of potential health problems.</p>\n\n<p>Extreme alcohol consumption can cause memory loss, loss of coordination and <a href=\"http://www.nhs.uk/Conditions/alcohol-poisoning/Pages/Introduction.aspx\" rel=\"noreferrer\">alcohol poisoning</a>, in some cases can be fatal.</p>\n\n<p>Health risks associated with drinking include:</p>\n\n<ul>\n<li><p>brain effects,</p>\n\n<p>Alcohol interferes with communication between nerve cells and all other cells limiting the ability to think clearly.</p>\n\n<p>First alcohol affects the forebrain responsible for motor coordination and decision making. Secondly it knocks out the midbrain, so you lose control over emotions and you've more chances of black outs.</p>\n\n<p><img src=\"https://i.stack.imgur.com/jmq6qm.jpg\" alt=\"How alcohol attacks the brain\"></p>\n\n<p>^{Image credits: <a href=\"http://immortalalcoholic.blogspot.co.uk/2011/12/rileys-brain-damage.html\" rel=\"noreferrer\">The Immortal Alcoholic</a>}</p>\n\n<blockquote>\n <p>Research has shown that animals fed alcohol during this critical developmental stage continue to show long-lasting impairment from alcohol as they age^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12638993\" rel=\"noreferrer\">2002</a>}. Subtle changes in the brain may be difficult to detect but still have a significant impact on long-term thinking and memory skills.^{<a href=\"http://pubs.niaaa.nih.gov/publications/AA67/AA67.htm\" rel=\"noreferrer\">NIH</a>}</p>\n</blockquote></li>\n<li><p>liver effects,</p>\n\n<p>Every time you drink, your liver has to filter it out of your blood and a lot of alcohol over a short period of time (<a href=\"https://en.wikipedia.org/wiki/Blood_alcohol_content\" rel=\"noreferrer\">BAC</a>) won't give enough time for the body to process it all.</p>\n\n<p>In addition persons below the age of 25 and women may process alcohol more slowly^{<a href=\"https://en.wikipedia.org/wiki/Blood_alcohol_content#Metabolism_and_excretion\" rel=\"noreferrer\">wiki</a>}.</p>\n\n<blockquote>\n <p>Elevated liver enzymes, indicating some degree of liver damage, have been found in some adolescents who drink alcohol^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11584156\" rel=\"noreferrer\">2001</a>}.</p>\n \n <p>Young drinkers who are overweight or obese showed elevated liver enzymes even with only moderate levels of drinking^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10839867\" rel=\"noreferrer\">2000</a>}.</p>\n</blockquote></li>\n<li><p>growth and endocrine effects,</p>\n\n<p>Consuming alcohol largely affects the body's endocrine system resulting in changes of various hormone levels which can disrupt a normal growth.</p>\n\n<blockquote>\n <p>Drinking alcohol during puberty period of rapid growth and development may upset the critical hormonal balance necessary for normal development of organs, muscles, and bones. Studies in animals also show that consuming alcohol during puberty adversely affects the maturation of the reproductive system^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11910704\" rel=\"noreferrer\">2001</a>}.</p>\n</blockquote>\n\n<p>See: <a href=\"https://en.wikipedia.org/wiki/Alcohol_and_cortisol\" rel=\"noreferrer\">Alcohol and cortisol</a> at Wikipedia</p></li>\n</ul>\n\n<p>^{Source: <a href=\"http://pubs.niaaa.nih.gov/publications/AA67/AA67.htm\" rel=\"noreferrer\">Underage Drinking at NIAAA</a>}</p>\n", "score": 20 } ]

[ "side-effects", "alcohol", "pediatrics" ]

[ { "answer_id": 60, "body": "<p>High consumption of sugar can up the risk of diabetes, but it is not the only contributing factor. There have been studies that have shown that sugar-sweetened drinks (mainly soda) have increased the probability of type 2 diabetes.<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23620057\">¹</a> There is a less subtle way that sugar can cause diabetes, which is by weight gain.<a href=\"http://ajcn.nutrition.org/content/76/5/911.full.pdf+html\">²</a> Obesity has been shown to cause diabetes<a href=\"http://www.medicinenet.com/script/main/art.asp?articlekey=39840\">³</a> and too much sugar can cause obesity, so technically sugar can cause obesity.</p>\n\n<p>In conclusion, sugar is fine in moderation (as most things are) and usually it won't cause diabetes. There are some links between the two though.</p>\n\n<hr>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23620057\">1</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23620057\">Consumption of sweet beverages and type 2 diabetes incidence in European adults: results from EPIC-InterAct.</a>}</p>\n\n<p>^{[<a href=\"http://ajcn.nutrition.org/content/76/5/911.full.pdf+html\">2</a>] <a href=\"http://ajcn.nutrition.org/content/76/5/911.full.pdf+html\">Fructose, weight gain, and the insulin resistance syndrome</a>}</p>\n\n<p>^{[<a href=\"http://www.medicinenet.com/script/main/art.asp?articlekey=39840\">3</a>] <a href=\"http://www.medicinenet.com/script/main/art.asp?articlekey=39840\">Why Does Obesity Causes Diabetes?</a>}</p>\n", "score": 22 }, { "answer_id": 12754, "body": "<p>Consumption of carbohydrates is necessary to sustain life and mental health. Eating or drinking carbs stresses the body both when consuming too much or too little. Today's diabetic diet do include carbohydrates. </p>\n\n<p>For a little background, the pancreas serves two functional purposes. It provides the endocrine hormones that balance the sugar available in the blood stream. For the endocrine function, it produces insulin and glucagon from the Beta cells. Insulin is the catalyst for cells to pull in sugar from the blood. Glucagon tells the liver to dump glycogen to raise up blood sugar. The glucagon is dumped when the pituitary signals the adrenal glands to go into fight-or-flight mode. It boosts the available energy. Drinking simple sugars like the ones in soft drinks is an easily metabolized sugar, and it makes the pancreas work extra hard. At the same time, if the person has insulin resistance, the pancreas has to pump out even more to get the sugar from the blood into cells. Eventually the pancreas just stops functioning when it is worked too hard.</p>\n\n<p>The second function of the pancreas is exocrine, and it produces enzymes to help the body digest food and absorb vitamins. One of the enzymes also aids in the digestion of carbohydrates. </p>\n\n<p>So to make a long story short, yes, consuming high amounts of sugar may increase your risk of diabetes, especially type 2. However, the bigger risks factors, for diabetes and the potential of pancreatic cancer, are stress, alcohol consumption and eating red meats. </p>\n\n<p>Here is a link to the American Diabetes Association answering your very <a href=\"http://www.diabetes.org/diabetes-basics/myths/?loc=db-slabnav\" rel=\"nofollow noreferrer\">question</a>. Here is more information about how to treat your pancreas with <a href=\"https://www.pancan.org/facing-pancreatic-cancer/diet-and-nutrition/diabetes-and-pancreatic-cancer/\" rel=\"nofollow noreferrer\">respect</a>. The pancreas will demand respect eventually, and working with it helps to ease many complications of disease.</p>\n", "score": 4 } ]

[ "diabetes", "sugar" ]

[ { "answer_id": 10, "body": "<p>Both. Human cells largely exhibit a phenomenon called <em>senescence</em> - they just give up and die after they reach a certain age via a biochemical mechanism called <em><a href=\"http://www.ncbi.nlm.nih.gov/books/NBK26873/\">apoptosis</a></em>. The outer limit of survivability for human cells is generally understood to be in the 100-120 year range. One of the things that makes a cancer cell cancerous is the deactivation of the signals for apoptosis, making the cell effectively immortal.</p>\n\n<p>At the same time, most illnesses, particularly the \"lifestyle illnesses\" (diabetes, hypertension, hypercholesterolemia) so common today, do induce some changes which shorten lifespan.</p>\n\n<p>The most significant changes which extended human life were the development of (a) sanitation and (b) antibiotics. These together dramatically reduced death by infectious disease. Removal of early death from infection exposed these diseases of late-life and lifestyle.</p>\n", "score": 25 }, { "answer_id": 1056, "body": "<p>The claim of modern medicine being responsible for longer lifespans is of course a statistical claim, i.e. the average/net effect. Thus your second assertion does not follow logically. Though it is an interesting point.</p>\n\n<p>Diseases, both now and in the past, do not have 100% mortality rates. If you followed the ebola outbreak you'd have heard stories of survivors are quite common. The same is true with measles, the common cold, lung infections, etc. When we find a cure for a disease the lifespan statistic increases. This is because those people who would have died survive instead, NOT because infected people avoid long-term collateral damage that would have taken a few years of their 'original' lifespan. At least that is the current predominant view of things.</p>\n\n<p>Consider the following:</p>\n\n<ul>\n<li>Diabetes decreases individual lifespan, ergo the average lifespan also decreases if enough people get diabetes.</li>\n<li>The common cold does not decrease individual lifespan, yet it still contributes to a lower average lifespan because it may be fatal in weak individuals.</li>\n</ul>\n\n<p>So we could say (almost) every illness shortens the <em>average</em> lifespan, but not every illness shortens <em>individual</em> lifespan.</p>\n", "score": 12 } ]

[ "life-expectancy", "disease", "statistics" ]

[ { "answer_id": 366, "body": "<p>There are lots of things you can do to be a responsible and considerate individual. Props for even asking this question!</p>\n\n<ol>\n<li><p>Cover your cough to prevent air-borne transmission with the inner part of your arm or your shoulder- whichever come into contact with other people less.</p></li>\n<li><p>Wash your hands with water and soap regularly for at least 20 seconds. That means before every meal and bathroom trip at least! Try as hot as you can bare so that it kills the bacteria. Carry hand sanitizer or some antibiotic wipes in case you don't have access to a sink or water.</p></li>\n<li><p>Rest and recovery (refer to anongoodnurse below) will build up antibodies. Try to get some sleep on your own and hold back on curling up with another person to avoid getting them sick too. <a href=\"http://www.webmd.com/sleep-disorders/features/healing-power-sleep\" rel=\"nofollow\">Be sure to change your sheets regularly as well</a>.</p></li>\n<li><p>Don't touch your face. Take caution to avoid eyes, nose, mouth, particularly.</p></li>\n<li><p>Use and carry tissues or napkins. Discard after use, wipe, or even just dabs. If you keep dabbing and leaving them on a surface, you'll risk contamination.</p></li>\n<li><p>Take a hot shower after you get home everyday. Doing so minimizes any other threatening particles that you may have acquired throughout the day.</p></li>\n<li><p>Don't share food or drinks with anyone. Anything your mouth touches will be contaminated and may sicken others.</p></li>\n<li><p>If you play a woodwind, try a decongestant so that you don't accidentally sneeze on a fellow band member and so that you can properly channel your breath.</p></li>\n</ol>\n\n<p>Side notes- \nIf the hot water starts drying out your skin, use a moisturizer.</p>\n\n<p>Feel better soon!</p>\n\n<p><a href=\"http://wwwnc.cdc.gov/travel/page/infectious-diseases\" rel=\"nofollow\">http://wwwnc.cdc.gov/travel/page/infectious-diseases</a></p>\n", "score": 9 }, { "answer_id": 449, "body": "<p>I'd like to offer a different perspective.</p>\n\n<p><strong>DaveL's answer is helpful if</strong> you absolutely have to carry on being a \"productive\" person and attend critical events for your career or life in general, all those recommendations DaveL offered will <em>reduce</em> the amount of people you'll infect, but chances are <em>you'll infect people anyway</em> because many diseases are infectious since before you show symptoms and you don't need to sneeze to spread it, talking can spread some viruses too, (e.g. the seasonal influenza is contagious since before you even know you are infected<a href=\"http://www.cdc.gov/flu/about/disease/spread.htm\" rel=\"noreferrer\">⁽¹⁾</a>). </p>\n\n<blockquote>\n <p>[...] flu viruses are spread mainly by droplets made when people with flu cough, sneeze <strong>or talk</strong>.\n [...] Most healthy adults may be able to infect other people beginning <strong>1 day before symptoms develop</strong> and up to 5 to 7 days after becoming sick. Children may pass the virus for longer than 7 days. Symptoms start 1 to 4 days after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. <strong>Some people can be infected with the flu virus but have no symptoms</strong>. During this time, those persons may still spread the virus to others.</p>\n</blockquote>\n\n<p>The <strong>social aspect</strong> is why people are <em>thanking you for even asking</em>. So from a social perspective, DaveL's recommendations are also helpful if you want others to <em>perceive</em> you're <em>trying</em> not to get them infected, but in reality some people will know you should have stayed home because many people around you <em>will</em> get infected<a href=\"http://www.cdc.gov/flu/about/disease/spread.htm\" rel=\"noreferrer\">⁽¹⁾</a> (but most importantly, you should stay home to get better). </p>\n\n<blockquote>\n <p>People with flu can spread it to others up to about 6 feet away.</p>\n</blockquote>\n\n<h3>First of all, you need the assistance of a professional to get properly diagnosed.</h3>\n\n<p>You need to know why you have this \"common cold\" symptoms, so your treatment is adequate for just having a common cold or something a bit more serious or a lot more dangerous, many illnesses display symptoms of the common cold (e.g. the flu, but the list is big).<a href=\"http://www.webmd.com/cold-and-flu/cold-guide/flu-cold-symptoms\" rel=\"noreferrer\">⁽²⁾</a></p>\n\n<blockquote>\n <p>Several hundred different viruses may cause your cold symptoms.</p>\n</blockquote>\n\n<p>In the mean time and while you get properly diagnosed, IMHO any disease that has the potential to be airborne infectious can be somewhat mitigated and contained following the procedures, precautions and advice given by CDC to contain and deal with the flu. So I will elaborate on that particular case (again, I can't stress this enough, <strong>ask for professional advice</strong>, this answer should only broaden your general sense of how to avoid contagion for you and for others to some degree).</p>\n\n<h3>Stay home if sick, or get vaccinated every season before you get sick (flu only).</h3>\n\n<ol>\n<li>People will appreciate that you stood home <strong>better</strong> than sneezing or coughing \"with the inner part of your arm\" (which by the way is more ritual than safe practice, it is better to fully cover your mouth and nose<a href=\"http://www.cdc.gov/flu/protect/covercough.htm\" rel=\"noreferrer\">⁽³⁾</a>). </li>\n<li>If you are the type of person who can't afford to stay home if you catch the flu, then <strong>the more reason</strong> you should get vaccinated every season<a href=\"http://www.cdc.gov/flu/protect/vaccine/index.htm\" rel=\"noreferrer\">⁽⁴⁾</a> (Getting vaccinated won't protect you against anything and everything but it will protect you from a broad range of flu type viruses). </li>\n</ol>\n\n<h3>1. About Staying home.<a href=\"http://www.cdc.gov/flu/protect/stopgerms.htm\" rel=\"noreferrer\">⁽⁵⁾</a></h3>\n\n<p>You don't <strong>\"have to\"</strong> attend anything that's not critical, attend your health and well being, that is critical. Staying home will dramatically reduce the amount of possible subjects to be infected, in this case your family, so stay home and follow all hygienic recommendations.</p>\n\n<ul>\n<li>Ventilate your house and specially your room, if you have a window to\nthe street, open that (unless it is raining outside).</li>\n<li>Change your sheets and blankets as regular as possible (every 2-3\ndays until 5 days after you recovered, 7 days for children). Do it\nwhen you're alone and everyone else went to work/school. If you have\nboth washing and drying machines, great, if not, at least take them\nout to the sun, <em>do not</em> keep infected used blankets inside your\nhome.</li>\n</ul>\n\n<blockquote>\n <p>If possible, stay home from work, school, and errands when you are sick. You will help prevent others from catching your illness.</p>\n</blockquote>\n\n<h3>2. About Getting Vaccinated.<a href=\"http://www.cdc.gov/flu/protect/keyfacts.htm\" rel=\"noreferrer\">⁽⁶⁾</a> (flu only)</h3>\n\n<p>The best prevention is not to get sick at all.\nIf you're not sick then you're not contagious.</p>\n\n<blockquote>\n <p>The single best way to prevent the flu is to get a flu vaccine each season. The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. There are several flu vaccine options for the 2014-2015 flu season. </p>\n</blockquote>\n\n<h3>Some additional info.</h3>\n\n<p>Virus that are so commonly transmitted like the flu are not going away anytime soon. Unless all potential hots/carriers get vaccinated at the same time repeatedly season after season until all types (A, B &amp; C types)<a href=\"http://www.cdc.gov/flu/about/viruses/types.htm\" rel=\"noreferrer\">⁽⁷⁾</a> of influenza viruses die with no viable hosts to replicate and evolve on. </p>\n\n<blockquote>\n <p>There are three types of influenza viruses: A, B and C. Human influenza A and B viruses cause seasonal epidemics of disease almost every winter in the United States. The emergence of a new and very different influenza virus to infect people can cause an influenza pandemic. Influenza type C infections cause a mild respiratory illness and are not thought to cause epidemics.</p>\n</blockquote>\n\n<p>Those viable hosts include more than 7 billion human beings and who knows how many animals that can carry along the virus and help it keep evolving<a href=\"http://www.cdc.gov/flu/about/viruses/transmission.htm\" rel=\"noreferrer\">⁽⁸⁾</a></p>\n\n<p><img src=\"https://i.stack.imgur.com/prX5d.png\" alt=\"a graphic table depicting the kind of animals affected by different strands of influenza; which include humans, poultry, pigs, and to less degree other animals including bats \"></p>\n\n<h3>And most importantly, consult your GP.</h3>\n\nReference index.\n\n<p>_{\n1. <a href=\"http://www.cdc.gov/flu/about/disease/spread.htm\" rel=\"noreferrer\">How Flu Spreads</a>\n2. <a href=\"http://www.webmd.com/cold-and-flu/cold-guide/flu-cold-symptoms\" rel=\"noreferrer\">Flu or Cold Symptoms?</a>\n3. <a href=\"http://www.cdc.gov/flu/protect/covercough.htm\" rel=\"noreferrer\">Cover Your Cough</a>\n4. <a href=\"http://www.cdc.gov/flu/protect/vaccine/index.htm\" rel=\"noreferrer\">Preventing Seasonal Flu With Vaccination</a>\n5. <a href=\"http://www.cdc.gov/flu/protect/stopgerms.htm\" rel=\"noreferrer\">Stopping the Spread of Germs at Home, Work &amp; School</a>\n6. <a href=\"http://www.cdc.gov/flu/protect/keyfacts.htm\" rel=\"noreferrer\">Key Facts About Seasonal Flu Vaccine</a>\n7. <a href=\"http://www.cdc.gov/flu/about/viruses/types.htm\" rel=\"noreferrer\">Types of Influenza Viruses</a>\n8. <a href=\"http://www.cdc.gov/flu/about/viruses/transmission.htm\" rel=\"noreferrer\">Transmission of Influenza Viruses from Animals to People</a>\n}</p>\n", "score": 5 }, { "answer_id": 367, "body": "<p>A cold can be spread through:</p>\n\n<ul>\n<li>direct contact (via airborne droplets) – if you sneeze or cough, tiny droplets of fluid containing the cold virus are launched into the air and can be breathed in by others</li>\n<li>indirect contact – if you sneeze onto a door handle and someone else touches the handle a few minutes later, they may catch the cold virus if they then touch their mouth or nose.</li>\n</ul>\n\n<p>These things can help you to prevent it from spreading:</p>\n\n<ul>\n<li><strong>wash your hands regularly</strong> and properly, particularly after touching your nose or mouth and before handling food,</li>\n<li><strong>always sneeze and cough into tissues</strong> as this will help to prevent the virus-containing droplets from your nose and mouth entering the air where they can infect others; throw away used tissues immediately and wash your hands,</li>\n<li><strong>clean surfaces regularly</strong> to keep them free of germs,</li>\n<li><strong>use your own cup</strong>, plates, cutlery and kitchen utensils,</li>\n<li><strong>use disposable paper towels</strong> to dry your hands and face, rather than shared towels and always dispose of the paper towels after you have finished using them,</li>\n<li>use disposable devices that <strong>cover your mouth</strong> and nose with scarf, veil, face shields or surgical mask while sitting with people which will provide minimal protection from viruses for other people around.</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/conditions/Cold-common/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">Cold, common: Introduction</a> and <a href=\"http://www.nhs.uk/conditions/cold-common/pages/prevention-old.aspx\" rel=\"nofollow noreferrer\">Preventing a common cold</a> at NHS}</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"https://health.stackexchange.com/q/417/114\">How long is someone infectious after a cold?</a></li>\n<li><a href=\"https://health.stackexchange.com/q/452/114\">Effect of the common cold on the immune system</a></li>\n</ul>\n", "score": 3 } ]

[ "common-cold" ]

[ { "answer_id": 7673, "body": "<p>For most people, it is better to sleep <em>with</em> a pillow according to the latest research.</p>\n\n<ul>\n<li>Sleeping without a pillow <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24248001\" rel=\"noreferrer\">increases interocular pressure</a> which is considered a risk for glaucoma patients. </li>\n<li>Sleeping on your side without a pillow increases your risk of osteoarthritis in the neck. If you sleep on your side, your cervical spine bends to the bed. This pinches the openings of the spine (the foramina) and causes bones to push and rub against each other. That friction and pressure causes bone to erode and grow which can create the bone spurs you can often see on cervical x-rays of patients. A pillow raises the head and straightens the spine. <a href=\"https://i.stack.imgur.com/VW1td.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/VW1td.jpg\" alt=\"cervical spine with a pillow\"></a></li>\n<li>Sleeping on your back without a pillow changes your neck angle from its normal daily position. When standing, your neck also has a certain curve to it. If you sleep on your back, that curve is also distorted. To simulate the natural curve of the neck, researchers found that about <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/26512267\" rel=\"noreferrer\">10cm of pillow is needed</a>. </li>\n</ul>\n\n<p>In general, studies suggest that sleeping with a pillow improves sleep quality and fits more physiologically and mechanically with the natural curve of the cervical spine. Even the Egyptians over 3,000 years ago used pillows. Here is King Tutankhamen's headrest around which his pillow linens were wrapped.</p>\n\n<p><a href=\"https://i.stack.imgur.com/iEdV8.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/iEdV8.jpg\" alt=\"Tut&#39;s pillow\"></a></p>\n\n<p>You can read additional <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=sleep%20without%20pillow\" rel=\"noreferrer\">studies here through PubMed</a>.</p>\n", "score": 16 } ]

[ "sleep", "spine", "position" ]

[ { "answer_id": 76, "body": "<p>Caffeine metabolism has to do with your genetic makeup. The slower you metabolize caffeine, the more effect it will have on you. The cause for the differences that people have in how fast they metabolize caffeine has to depend on the CYP1A2 gene. Variants of this gene can cause you to metabolize faster or slower. The C allele variant in the AHR gene, which controls the turning on and off the the CYP1A2 gene, is common in people who have a high metabolism for caffeine. You probably do not have this variant. That with a few other factors that depend on variants in your DNA are the reason that caffeine has a strong effect on you.</p>\n\n<hr>\n\n<p>^{<a href=\"http://www.gbhealthwatch.com/Trait-Caffeine-Consumption.php\">Caffeine Consumption</a>}</p>\n", "score": 19 }, { "answer_id": 231, "body": "<p>All caffeinated beverages like coffee (even decaffeinated) and soft drinks give short bursts of energy, temporarily raise blood pressure, and reduces blood flow to inactive limbs.</p>\n\n<p>Soon after you drink coffee (containing caffeine), it’s absorbed through the small intestine and dissolved into the bloodstream and it’s able to penetrate the blood-brain barrier and enter the brain.</p>\n\n<p>Your sensitivity really depends on your body tolerance threshold (e.g. renal threshold for blood) and your average daily intake, in other words it's determined by the efficiency of the human body to process and metabolize caffeine. It's usually to do with person’s unique DNA which determines to what degree a given amount of caffeine will affect a person (as described in the other answer).</p>\n\n<p>See also: <a href=\"https://coffee.stackexchange.com/questions/464/what-are-the-side-effects-of-drinking-too-much-coffee\">What are the side effects of drinking too much coffee?</a></p>\n", "score": 5 } ]

[ "caffeine", "drug-metabolism", "energy", "shake-tremble-fidget" ]

[ { "answer_id": 307, "body": "<p>I think a missing bit of information that might help you get a better sense of this practice is: <strong>steroids are miracle drugs.</strong> </p>\n\n<p>OK, that was in jest - no miracles here. Truth be told, though, if there is a single class of drugs that has added more <a href=\"http://en.wikipedia.org/wiki/Quality-adjusted_life_year\">quality-adjusted life-years</a> to human history than any other, steroids must be competing with just a few antibiotic classes for that title.</p>\n\n<p>To make clear what we’re talking about, the term “steroid” as a label for drugs generally refers to <a href=\"http://en.wikipedia.org/wiki/Glucocorticoid\">glucocorticoids</a> (GCs) - drugs that act like cortisol, an endogenous steroid hormone. Commonly used GCs include:</p>\n\n<ul>\n<li><strong>Short acting</strong>: hydrocortisone, cortisone</li>\n<li><strong>Intermediate-acting</strong>: prednisone, prednisolone, mehthylprednisolone, triamcinolone</li>\n<li><strong>Long-acting</strong>: betamethasone, dexamethasone, paramethasone</li>\n</ul>\n\n<p>Your question poses a specific example of one indication for steroids but seems to be asking about the use of these drugs more generally. As others have brought up, any decision about drug treatment involves weighing the <a href=\"http://en.wikipedia.org/wiki/Risk%E2%80%93benefit_ratio\"><strong>risk-benefit ratio</strong></a>.</p>\n\n<h2>Benefits</h2>\n\n<p>Although going through the efficacy data for various conditions is beyond the scope of this answer, I list a sampling of the common indications for GC treatment, and in the concluding paragraph I will provide specific efficacy data for arthritis. </p>\n\n<ul>\n<li><p><strong>Replacement therapy</strong>: due to either primary adrenal insufficiency (<a href=\"http://www.mayoclinic.org/diseases-conditions/addisons-disease/basics/definition/con-20021340\">Addison’s disease</a>) or secondary/tertiary insufficiency (at the level of the hypothalamus or pituitary. </p></li>\n<li><p><strong>Inflammatory conditions</strong> (deep breath in): asthma, eczema, inflammatory bowel disease, allergic rhinitis/sinusitis, eosinophilic anything, inflammatory arthritis, anaphylaxis, septic shock (in very specific circumstances), polymyalgia rheumatica, polyarteritis nodosa, temporal arteritis, minimal change glomerulonephritis, autoimmune hemolytic anemia, urticaria, autoimmune hepatitis</p></li>\n<li><p><strong>Other things that aren’t (necessarily) obviously inflammatory</strong>: increased intracranial pressure, intractable nausea, acute leukemia, sarcoidosis, cluster headaches, dermatomyositis</p></li>\n</ul>\n\n<h2>Risks</h2>\n\n<p>First, please note that a few of the indications for GC require only a very brief burst of high-dose GC. In this time course, these drugs actually very few serious side effects (psychiatric effects and hyperglycemia are exceptions, but rarely outweigh the benefit). Over the longer term, however, supra-physiologic doses of GC have an array of adverse effects that fall into a few categories:</p>\n\n<ul>\n<li><p><strong>Suppression of the hypothalamus-pituitary-adrenal (HPA) axis</strong>: Exogenous GCs suppress the hypothalamic pathway that stimulates the adrenal gland, resulting in adrenal atrophy. This means that if the exogenous GC is abruptly discontinued, <a href=\"http://www.nlm.nih.gov/medlineplus/ency/article/000357.htm\">adrenal crisis</a> can ensue. The rule of thumb I learned was that >3 weeks treatment with >10 mg prednisone (or equivalent) can cause HPA suppression. As a result, GC treatment that meets these criteria is generally ended with a taper, allowing the adrenal to regenerate, whereupon it can resume normal function.<br><br>\nThis side effect is usually a non-issue if the medication is tapered correctly. Therefore, the benefits of treatment will generally outweigh the risks.</p></li>\n<li><p><strong>Cushing’s syndrome</strong>: This term is generally applied to the constellation of symptoms occuring with chronic administration of supra-physiologic doses of GC. <br> </p>\n\n<ul>\n<li>Hyperglycemia </li>\n<li>Hypertension </li>\n<li>Psychiatric effects: insomnia, precipitation of mania or psychosis in susceptible individuals</li>\n<li>Salt retention¹</li>\n<li>Decreased bone mineral density</li>\n<li>Weight gain: generally in a pattern characterized by central adiposity and peripheral muscle atrophy</li>\n<li>Increased intra-ocular pressure</li>\n</ul></li>\n</ul>\n\n<p>So, after all that:</p>\n\n<blockquote>\n <p>Why do doctors prescribe steroid tablets though they knew the side effect?</p>\n</blockquote>\n\n<p>Because the benefit outweighs the risk.² For the example you gave &mdash; arthritis³ &mdash; the best paper I found was a <a href=\"http://rheumatology.oxfordjournals.org/content/48/7/807.long\">meta-analysis</a> that used a statistical method that compares the <a href=\"http://en.wikipedia.org/wiki/Number_needed_to_treat\">number needed to treat</a> (NNT) with the <a href=\"http://en.wikipedia.org/wiki/Number_needed_to_harm\">number needed to harm</a> (NNH) for long-term (>1 year) treatment of rheumatoid arthritis. The ratio there NNH/NNT was 0.25, which is considered “good.” I’ll let you read their methods if you’d like the details. For further reading on this methodology and insights into how we quantitatively assess the comparison between risks and benefits, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=20412543\">this article by Guo et al.</a> provides some good bedtime reading.</p>\n\n<hr>\n\n<p>_{\n<strong>Notes</strong>:\n}<br>\n_{\n1. This is actually a mineralocoricoid rather than a GC effect, only present for those GCs whose receptor specificity overlaps, most prominently the short-acting agents hydrocortisone and cortisone.\n} </p>\n\n<p>_{\n2. Usually. Steroids are probably over-used in some settings because most people know that steroids tend to “make everybody feel better.” They can be an easy way to make patients happy if the side effects aren’t fully appreciated. Thus (in case you needed me to tell you!), your question is a valid one.\n}<br><br>\n_{\n3. I’m assuming here rheumatoid arthritis, because this is the most common type of arthritis for which steroids are appropriate. For the more common osteo-“arthritis” &mdash; a.k.a. degenerative joint disease &mdash; I’m sure steroids would make patients feel better, but the benefit there <em>rarely</em> outweighs the risk.</p>\n\n<h2>}</h2>\n\n<p>_{\n<strong>References:</strong>\n} <br>\n_{\nGuo JJ, Pandey S, Doyle J, Bian B, Lis Y, Raisch DW. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=20412543\"><em>A review of quantitative risk-benefit methodologies for assessing drug safety and efficacy-report of the ISPOR risk-benefit management working group.</em></a> Value Health. 2010 Aug;13(5):657-66.\n} </p>\n\n<p>_{\nLiu D, Ahmet A, Ward L, Krishnamoorthy P, Mandelcorn ED, Leigh R, Brown JP, Cohen A, Kim H. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=A+practical+guide+to+the+monitoring+and+management+of+the+complications+of+systemic+corticosteroid+therapy\"><em>A practical guide to the monitoring and management of the complications of systemic corticosteroid therapy.</em></a> Allergy Asthma Clin Immunol. 2013 Aug 15;9(1):30.\n} </p>\n\n<p>_{\nMycek RJ, Harvey RA, Champe PC. <em>Pharmacology</em>. Lippincotts’s Illustrated Reviews, 2nd Ed. Lippincott, 1997: 272-276.\n} </p>\n\n<p>_{\nRavindran V, Rachapalli S, Choy EH.Rheumatology (Oxford). <a href=\"http://rheumatology.oxfordjournals.org/content/48/7/807.long\">Safety of medium- to long-term glucocorticoid therapy in rheumatoid arthritis: a meta-analysis.</a> 2009 Jul;48(7):807-11.\n}</p>\n\n<hr>\n", "score": 30 }, { "answer_id": 151, "body": "<p>This is a very good question.</p>\n\n<p>Simply put: among doctors we call them <em>wonder drugs</em> or <em>life saving drugs</em>. In a number of emergencies, such as severe drug reactions, life-threatening asthma or allergies, or inflammatory conditions (such as your example of arthritis), no other drugs act like steroids. They act quickly and effectively, reducing inflammation and decreasing allergic responses, opening swollen airways, etc. They are used because they are so effective.</p>\n\n<p>Steroids do have side effects; they can cause kidney stones, decrease bone density, may cause diabetes, nervous system related diseases and many more, but only when used continuously for more than 3 to 6 months or so. Usually, however, steroids are only used until the patient is out of danger or experiences relief of their sudden severe pain. </p>\n\n<p>Steroids are not alien to our bodies; they are naturally produced by the adrenal gland, which lies above kidney. Therefore they are unlike paracetamol (which we take for fever) and other drugs which are synthetic (not natural). By giving steroids to patients, we are just strengthening a natural response our bodies attempt to mount. </p>\n\n<p>I suggest you not take any steroid for more than 3 months, and only under a doctor's supervision. Your doctor can advise you of any alternatives to steroids if available.</p>\n", "score": 6 }, { "answer_id": 190, "body": "<p>The reason drugs with adverse side effects are prescribed are </p>\n\n<ol>\n<li>Generally the benefits outweigh the risk,</li>\n<li>Every side effect that was discovered during trials, no matter how rare, must be listed, and</li>\n<li>Hopefully the FDA in the US or the similar administration in the other countries did their due diligence in order to protect consumers from drug companies.</li>\n</ol>\n\n<p>Doctors only prescribe untested drugs to terminal ill patients who sign numerous waivers in order to take them. So on average, a patient should only rarely experience the side effects and usually the milder ones will present; however, some people will present with the more serious adverse reactions. </p>\n\n<p>Additionally, if any side effect does present itself, the patient should consult their physician since alternatives may be available.</p>\n", "score": 2 } ]

[ "medications", "steroids", "side-effects" ]

[ { "answer_id": 13714, "body": "<h2>We do not know</h2>\n\n<p>That's a bit unsatisfying as an answer, but it's the truth. Vaping is around for somewhat 13 years (<a href=\"http://articles.latimes.com/2009/apr/25/world/fg-china-cigarettes25\" rel=\"noreferrer\">invented in 2003</a>), but the international breakthrough was so recent that no long term studies have been conducted with meaningful results. </p>\n\n<p>This is all there is to it. Feel free to read extracts from the studies below to get a broader understanding of how complicated and convoluted research in this area is.</p>\n\n<hr>\n\n<p><strong>Sources stating it's at least healthier than tobacco cigarettes</strong> </p>\n\n<p><em><a href=\"http://journals.sagepub.com/doi/10.1177/0194599814536847\" rel=\"noreferrer\">Electronic Nicotine Delivery Systems (“E-cigarettes”)</a></em> \nPaul Truman Harrell, PhD, Vani Nath Simmons, PhD, John Bernard Correa, Tapan Ashvin Padhya, MD, Thomas Henry Brandon, PhD<br>\nOtolaryngology-Head and Neck Surgery Vol 151, Issue 3, pp. 381 - 393<br>\nFirst published date: June-04-2014 , DOI: 10.1177/0194599814536847</p>\n\n<blockquote>\n <p>E-cigarettes currently vary widely in their contents and are sometimes inconsistent with labeling. <strong>Compared to tobacco cigarettes, available evidence suggests that e-cigarettes are often substantially lower in toxic content, cytotoxicity, associated adverse effects, and secondhand toxicity exposure.</strong> Data on the use of e-cigarettes for quitting smoking are suggestive but ultimately inconclusive.</p>\n</blockquote>\n\n<p><em><a href=\"https://www.karger.com/Article/FullText/360220#\" rel=\"noreferrer\">Estimating the Harms of Nicotine-Containing Products Using the MCDA Approach</a></em>. Nutt D, J, Phillips L, D, Balfour D, Curran H, V, Dockrell M, Foulds J, Fagerstrom K, Letlape K, Milton A, Polosa R, Ramsey J, Sweanor D, Eur Addict Res 2014;20:218-225</p>\n\n<blockquote>\n <p><strong>Findings</strong>: Weighted averages of the scores provided a single, overall score for each product. Cigarettes (overall weighted score of 100) emerged as the most harmful product, with small cigars in second place (overall weighted score of 64). After a substantial gap to the third-place product, pipes (scoring 21), all remaining products scored 15 points or less.<br>\n <strong>Interpretation</strong>: Cigarettes are the nicotine product causing by far the most harm to users and others in the world today. <strong>Attempts to switch to non-combusted sources of nicotine should be encouraged as the harms from these products are much lower.</strong></p>\n</blockquote>\n\n<p><em><a href=\"http://journals.lww.com/co-otolaryngology/pages/articleviewer.aspx?year=2015&amp;issue=10000&amp;article=00004&amp;type=abstract\" rel=\"noreferrer\">Preventing or reducing smoking-related complications in otologic and neurotologic surgery.</a></em> Golub, Justin S.; Samy, Ravi N. Otolaryngology &amp; Head &amp; Neck Surgery: October 2015 - Volume 23 - Issue 5 - p 334–340\ndoi: 10.1097/MOO.0000000000000184</p>\n\n<blockquote>\n <p>Cigarette smoking negatively influences otologic surgery results, mostly because of tobacco combustion byproducts. Counseling and, if needed, pharmacologic measures to reduce smoking are recommended. E-cigarettes that deliver nicotine in water vapor may be safer than tobacco smoking. Our review contributes to the discussion of how the trends of e-cigarette use and marijuana legalization will unfold in the future to affect our patients’ outcomes.</p>\n</blockquote>\n\n<p><em><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350653/\" rel=\"noreferrer\">Electronic cigarettes: patterns of use, health effects, use in smoking cessation and regulatory issues.</a></em> Rahman MA, Hann N, Wilson A, Worrall-Carter L. Tobacco Induced Diseases. 2014;12(1):21. doi:10.1186/1617-9625-12-21.</p>\n\n<blockquote>\n <p>The literature search revealed 37 relevant articles. Findings suggest that e-cigarettes are mostly used by middle-aged current smokers, particularly males, to help them for quitting or for recreation. E-cigarettes contain very low levels of multiple toxic substances such as formaldehyde and acrolein, <strong>but these levels are many times lower than those found in cigarettes. They were found to have effectiveness in aiding smoking cessation to a limited degree.</strong> Debate continues regarding regulating their use for cessation versus heavy restrictions to control recreational use on the basis that it perpetuates nicotine addiction.</p>\n</blockquote>\n\n<hr>\n\n<p><strong>Sources stating it's as bad as nicotine patches or worse when looking for a substitute to cigarettes</strong> </p>\n\n<p><em><a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196(14)00989-6/abstract\" rel=\"noreferrer\">Counseling Patients on the Use of Electronic Cigarettes</a></em>. Jon O. Ebbert, MD, Amenah A. Agunwamba, ScD, MPH, Lila J. Rutten, PhD, MPH. Mayo Clinic Proceedings. January 2015, Volume 90, Issue 1, Pages 128–134.</p>\n\n<blockquote>\n <p>Clear evidence about the safety of e-cigarettes is <strong>lacking, and laboratory experiments and case reports suggest these products may be associated with potential adverse health consequences</strong>. The effectiveness of e-cigarettes for smoking cessation is <strong>modest and appears to be comparable to the nicotine patch combined with minimal behavioral support</strong>. Although a role for e-cigarettes in the treatment of tobacco dependence may emerge in the future, the potential risk of e-cigarettes outweighs their known benefit as a recommended tobacco treatment strategy by clinicians. Patients should be counseled on the known efficacy and potential risks of e-cigarettes.\n <a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196(14)00989-6/abstract\" rel=\"noreferrer\">http://www.mayoclinicproceedings.org/article/S0025-6196(14)00989-6/abstract</a></p>\n</blockquote>\n\n<hr>\n\n<p><strong>Sources stating it's unclear whether it can be used for tobacco cessation</strong></p>\n\n<p><em><a href=\"http://annals.org/aim/article/2443060/behavioral-pharmacotherapy-interventions-tobacco-smoking-cessation-adults-including-pregnant-women\" rel=\"noreferrer\">Behavioral and Pharmacotherapy Interventions for Tobacco Smoking Cessation in Adults, Including Pregnant Women: U.S. Preventive Services Task Force Recommendation Statement.</a></em> Siu AL. Ann Intern Med. 2015;163:622–634. doi: 10.7326/M15-2023</p>\n\n<blockquote>\n <p>The USPSTF concludes that the current evidence is <strong>insufficient to recommend electronic nicotine delivery systems for tobacco cessation in adults</strong>, including pregnant women. The USPSTF recommends that clinicians direct patients who smoke tobacco to other cessation interventions with established effectiveness and safety.\n <a href=\"http://annals.org/aim/article/2443060/behavioral-pharmacotherapy-interventions-tobacco-smoking-cessation-adults-including-pregnant-women\" rel=\"noreferrer\">http://annals.org/aim/article/2443060/behavioral-pharmacotherapy-interventions-tobacco-smoking-cessation-adults-including-pregnant-women</a></p>\n</blockquote>\n\n<hr>\n\n<h2>Further reading</h2>\n\n<ul>\n<li><a href=\"https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/457102/Ecigarettes_an_evidence_update_A_report_commissioned_by_Public_Health_England_FINAL.pdf\" rel=\"noreferrer\">E-cigarettes: an evidence update. A report commissioned by Public Health England</a></li>\n<li>DrugFacts from DrugAbuse.gov, <a href=\"https://www.drugabuse.gov/publications/drugfacts/cigarettes-other-tobacco-products\" rel=\"noreferrer\">Cigarettes and Other Tobacco Products</a></li>\n<li>The Royal College of Physicians in London: <a href=\"https://www.rcplondon.ac.uk/projects/outputs/nicotine-without-smoke-tobacco-harm-reduction-0\" rel=\"noreferrer\">Nicotine without smoke: Tobacco harm reduction</a></li>\n<li>FDA Rule about Tobacco Products <a href=\"https://www.federalregister.gov/documents/2016/05/10/2016-10685/deeming-tobacco-products-to-be-subject-to-the-federal-food-drug-and-cosmetic-act-as-amended-by-the\" rel=\"noreferrer\">(<em>Deeming Tobacco Products To Be Subject to the Federal Food, Drug, and Cosmetic Act, as Amended by the Family Smoking Prevention and Tobacco Control Act; Restrictions on the Sale and Distribution of Tobacco Products and Required Warning Statements for Tobacco Products</em>)</a></li>\n</ul>\n\n<hr>\n\n<p><a href=\"https://i.stack.imgur.com/5G4Pz.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/5G4Pz.png\" alt=\"enter image description here\"></a>\n<strong>References of the image</strong></p>\n\n<ul>\n<li>(28 April 2015). \"E-cigarettes: Considerations for the otolaryngologist.\". International journal of pediatric otorhinolaryngology. DOI:10.1016/j.ijporl.2015.04.032. PMID 25998217.</li>\n<li>(2014). \"Science and Electronic Cigarettes\". Journal of Addiction Medicine 8 (4): 223–233. DOI:10.1097/ADM.0000000000000049. PMID 25089952. PMC: 4122311. ISSN 1932-0620.</li>\n<li>(2016). \"Corneoscleral Laceration and Ocular Burns Caused by Electronic Cigarette Explosions\". Cornea 35 (7): 1015–1018. DOI:10.1097/ICO.0000000000000881. PMID 27191672. PMC: 4900417. ISSN 0277-3740.</li>\n<li>Grana, R (13 May 2014). \"E-cigarettes: a scientific review.\". Circulation 129 (19): 1972–86. DOI:10.1161/circulationaha.114.007667. PMID 24821826. PMC: 4018182.</li>\n<li>Ebbert, Jon O. (2015). \"Counseling Patients on the Use of Electronic Cigarettes\". Mayo Clinic Proceedings 90 (1): 128–134. DOI:10.1016/j.mayocp.2014.11.004. PMID 25572196. ISSN 00256196.</li>\n<li>Orellana-Barrios, Menfil A. (2015). \"Electronic cigarettes-a narrative review for clinicians\". The American Journal of Medicine. DOI:10.1016/j.amjmed.2015.01.033. PMID 25731134. ISSN 00029343.</li>\n<li>(2017). \"E-Cigarettes and Smoking Cessation: A Primer for Oncology Clinicians\". Clin J Oncol Nurs. DOI:10.1188/17.CJON.54-63. PMID 28107337.</li>\n</ul>\n\n<p>Author of the Image: Mikael Häggström<br>\nImage Source: <a href=\"https://en.wikipedia.org/wiki/File:Adverse_effects_of_vaping_(raster).png#Summary\" rel=\"noreferrer\">Wikipedia</a></p>\n", "score": 29 }, { "answer_id": 13724, "body": "<p>The question might need isolation into two parts: </p>\n\n<ol>\n<li>Nicotine addiction vs. inhaling combusted natural products </li>\n<li>Cessation and the mere use of vaped products.</li>\n</ol>\n\n<p>There should be little doubt that <em>not</em> habitually inhaling nitrosamines and aldehydes is probably better than doing so. In the end, however, the suggestion is equivalent to \"eating boiled steak is healthier than grilled steak\" - for the very same plethora of chemicals that give flavor, but are the result of combustion - whether fine Turkish tobacco or Kobe beef. I'll still take mine rare and blackened, please.</p>\n\n<p>Also, tempering the large research cited on <a href=\"https://health.stackexchange.com/a/13714\">Narusan-in-coma's answer</a> with the thought that \"vaping\" has created a whole large group of younger people that would not otherwise \"smoke\" burning tobacco, <em>the ultimate effects, as Narusan-in-coma points out, are not known.</em> Nor is research at all simple, as most \"vapor\" folks will not vape Frutopia Fun Blend #7 for decades, inhaling god-knows-what flavoring chemicals, with repeated long-term exposure and dosing.</p>\n\n<p>It can only be concluded that the combustion products are eliminated (or reduced by magnitudes). If <em>those</em> are considered Enemy #1, then one could make the leap to \"healthier\". But only with that assumption in place, and forsaking all others.</p>\n\n<p>\"Substitution\" presumes a nicotine addiction already in place. The health effects of nicotine addiction <em>by itself</em> (without combustion and environmental factors) have not been proven or even justified well in my mind. In fact, tests in rats have shown that nicotine alone may not be addictive at all. Which right or wrong proves <em>nothing</em>.</p>\n\n<p>I worked for many years with a renown DABT toxicologist, building devices to smoke cigarettes in a precise way, and deliver \"precision\" cigarette smoke to lab animals like rodents and lagomorphs. Not just for \"cancer\" type research, but psychology and performance physiology studies as well. In fact, the nicotine and tar content have to be measured constantly and accurately by tobacco companies, for the required labeling, since tobacco is a natural product and can vary from season to season. So I would say that I know a little something about this topic. Very very little.</p>\n\n<p>A mere living will eventually lead to death. Of this, and only this, I am certain.</p>\n\n<p><strong>On Edit:</strong> Cites added to demonstrate some of the claims I made, and to comply with this stack's guidelines. Note that I am not trying to <em>prove</em> anything; I merely demonstrated a \"path\" to a conculsion of \"healthier\" (vaping vs. smoking) - with the provisio assumption that <em>combustion</em> products represent the bulk of the health risk compared to mere nicotene in water vapor. It is only with this grand assumption one could come to a \"healthier\" conclusion. The last cite is an interesting one that suggests the most meaningful \"answer\" to the OP question, within the framework of my assertions.</p>\n\n<p><strong>Summary source detailing the inconsistent results in animal testing demonstrating nicotene alone, devoid of other environmental factors, is addictive in of itself:</strong></p>\n\n<blockquote>\n <p><strong>Effects of nicotine in experimental animals and humans: an update on addictive properties</strong></p>\n \n <p>Nicotine, a psychoactive component of tobacco,\n appears to play a major role in tobacco dependence, but reinforcing\n effects of nicotine have often been difficult to demonstrate directly\n in controlled studies with laboratory animals or human subjects: <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2687081/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2687081/</a></p>\n</blockquote>\n\n<p><strong>Sources alluding that aldehydes and nitrosamines are some of the most signifigant carcinogenic / COPD causal chemicals in burning tobacco:</strong></p>\n\n<blockquote>\n <p><strong>It is time to regulate carcinogenic tobacco-specific nitrosamines in cigarette tobacco</strong></p>\n \n <p>... immediate regulation of the carcinogenic tobacco-specific\n nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and\n N’-nitrosonornicotine (NNN) in cigarette tobacco as a logical path to\n cancer prevention. NNK and NNN, powerful carcinogens in laboratory\n animals, have been evaluated as “carcinogenic to humans” by the\n International Agency for Research on Cancer. \n <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4135519/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4135519/</a> </p>\n \n <p><strong>Critical role of aldehydes in cigarette smoke-induced acute airway inflammation.</strong></p>\n \n <p>Cigarette smoking (CS) is the most important risk factor for COPD,\n which is associated with neutrophilic airway inflammation. We\n hypothesize, that highly reactive aldehydes are critical for\n CS-induced neutrophilic airway\n inflammation:<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23594194\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/23594194</a></p>\n \n <p><strong>E-cigarettes generate high levels of aldehydes only in “dry puff” conditions</strong> </p>\n \n <p>...reports, accompanied by huge media campaigns, stating that e-cigarettes generate many times higher levels of carcinogenic\n aldehydes compared to tobacco cigarettes. We have always responded\n that such findings were the result of severe overheating of the\n device, which the vapers identify and avoid. We have repeatedly\n referred to the dry puff phenomenon as an explanation of these\n findings...:\n <a href=\"http://www.ecigarette-research.org/research/index.php/research/research-2015/210-ald\" rel=\"noreferrer\">http://www.ecigarette-research.org/research/index.php/research/research-2015/210-ald</a></p>\n</blockquote>\n", "score": 8 } ]

[ "smoking", "e-cigarette-vape" ]

[ { "answer_id": 22938, "body": "<p>The seasonal coronaviruses attach exclusively to cells with a ciliated epithelium.</p>\n<blockquote>\n<p>Coronaviruses invade the respiratory tract via the nose. After an incubation period of about 3 days, they cause the symptoms of a common cold, including nasal obstruction, sneezing, runny nose, and occasionally cough (Figs. 60-1 and 60-2). The disease resolves in a few days, during which virus is shed in nasal secretions. There is some evidence that the respiratory coronaviruses can cause disease of the lower airways but it is unlikely that this is due to direct invasion. Other manifestations of disease such as multiple sclerosis have been attributed to these viruses but the evidence is not clear-cut.</p>\n<p>Studies in both organ cultures and human volunteers show that <strong>coronaviruses are extremely fastidious and grow only in differentiated respiratory epithelial cells</strong>. Infected cells become vacuolated, show damaged cilia, and may form syncytia. Cell damage triggers the production of inflammatory mediators, which increase nasal secretion and cause local inflammation and swelling. These responses in turn stimulate sneezing, obstruct the airway, and raise the temperature of the mucosa.</p>\n</blockquote>\n<p>So, the mechanism of infection is such that they only attack the upper airways.</p>\n<p>The SARS-CoV-2 is totally different. It attaches to the ACE2 surface receptor which is found deep in alveolar pneumocytes. Their damage causes loss of surfactant in the alveoli, the collapse of these air cells that perform oxygen exchange and subsequently ARDS.</p>\n<p>So, seasonal coronaviruses give you a runny nose but don't kill. SARS-CoV-2 collapses the air sacs that allow oxygenation to occur.</p>\n<p><a href=\"https://www.ncbi.nlm.nih.gov/books/NBK7782/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/books/NBK7782/</a></p>\n", "score": 34 }, { "answer_id": 22964, "body": "<p>I should add here that there <a href=\"https://www.hindawi.com/journals/criid/2018/6796839/\" rel=\"nofollow noreferrer\">has been</a> a case of ARDS reported for the alphacoronavirus 229E (i.e. a \"common cold\" coronavirus) in 2018. But ARDS occurrences are of course, much less common in these \"common colds\" than in Covid-19 infections. The case report for 229E discusses the few other such occurrences:</p>\n\n<blockquote>\n <p>HCoV-229E has been associated with bronchitis, acute exacerbations of COPD, and pneumonia in infants, children, and elderly persons with underlying illnesses [11–13]. Life-threatening infections have only been described in immunocompromised patients [7, 8], but the correlation of HCoV-229E with LRTI in healthy adult individuals is uncertain [9]. An adult patient with pneumonia tested positive for HCoV-229E has been described in a study conducted in rural Thailand, but it is not made clear if other comorbidities were present [14]. Nine Italian patients hospitalized with LRTI have also been tested positive for HCoV-229E; however, their age is not specified [15]. Αlthough numerous studies have tentatively linked 229E infections to severe respiratory tract illness over many years, no study controlling for age and underlying illness has demonstrated an epidemiologic association between infection with HcoV-229E in healthy adults and any illness other than the common cold. Furthermore, <strong>no case of HCoV-229E-associated ARDS has been reported in immunocompetent adults.</strong> Only a few cases of pulmonary infection and ARDS have been described in a 76-year-old woman infected with the closely related alpha coronavirus HCoV-NL63 [16] and in a 39-year-old woman with poorly controlled DM and infected with the beta coronavirus HCoV-OC43.</p>\n</blockquote>\n\n<p>For severely immunocompromised patients however, there have been cases of 229E infection, triggering pneumonia e.g. as reported in (the papers referenced from the prviousone):</p>\n\n<ul>\n<li><a href=\"https://academic.oup.com/cid/article/37/7/929/422314\" rel=\"nofollow noreferrer\">\"Coronavirus 229E-Related Pneumonia in Immunocompromised Patients\"</a>\n\n<blockquote>\n <p>Here we report 2 well-documented cases of pneumonia related to coronavirus 229E, each with a different clinical presentation.</p>\n</blockquote></li>\n<li>or <a href=\"https://journal.chestnet.org/article/S0012-3692(16)35674-4/fulltext\" rel=\"nofollow noreferrer\">\"Coronavirus Pneumonia Following Autologous Bone Marrow Transplantation for Breast Cancer\"</a>\n\n<blockquote>\n <p>Rarely has coronavirus been linked, either by serology or nasal wash, to pneumonia. We report a case of a young woman who, following treatment for stage IIIA breast cancer using a high-dose chemotherapy regimen followed by autologous bone marrow and stem cell transplantation, developed respiratory failure and was found to have coronavirus pneumonia as diagnosed by electron microscopy from BAL fluid. </p>\n</blockquote></li>\n</ul>\n\n<p>But this is like a handful of cases in toto (for 229E).</p>\n\n<p>The ARDS case cited/mentioned in that (first) paper for NL63 was <a href=\"https://www.atsjournals.org/doi/full/10.1164/rccm.201506-1239LE\" rel=\"nofollow noreferrer\">reported in 2016</a>. This was also diagnosed by <a href=\"https://en.wikipedia.org/wiki/Bronchoalveolar_lavage\" rel=\"nofollow noreferrer\">BAL</a> + electron microscopy. This latter paper also suggests that in immunocompromised patients NL63 may be a bit more problematic (than 229E):</p>\n\n<blockquote>\n <p>In 2010, a case of fatal HCoV-NL63 pulmonary infection during the late-engraftment phase was reported (6). An Australian study reported that 2% of patients presenting to the hospital because of respiratory symptoms tested positive for HCoV-NL63, and 81% of these patients were diagnosed with lower respiratory tract disease; all of them required admission to the hospital, 56% had an abnormal chest xray, and one immunocompromised patient died, yet none of these patients had ARDS (7).</p>\n</blockquote>\n", "score": 5 } ]

[ "covid-19", "infection", "common-cold", "coronavirus", "sars-cov-2" ]

[ { "answer_id": 29280, "body": "<p>Race and ethnicity are risk factors in many diseases. Examples include, but are not limited to, cystic fibrosis and spinal muscular atrophy.</p>\n<p>There is also an epidemiological purpose of collecting this information. It is important to know if some disease is affecting some races or some ethnicities disproportionately. This is how it was found out that race or ethnicity <strong>is</strong> a risk factor in certain diseases in the first place.</p>\n<p><strong>RFERENCES:</strong></p>\n<p><em>Sheets L, Johnson J, Todd T, Perkins T, Gu C, Rau M. Unsupported labeling of race as a risk factor for certain diseases in a widely used medical textbook. Acad Med. 2011 Oct;86(10):1300-3. doi: 10.1097/ACM.0b013e31822bbdb5. PMID: 21869670. : <a href=\"https://pubmed.ncbi.nlm.nih.gov/21869670/\" rel=\"noreferrer\">https://pubmed.ncbi.nlm.nih.gov/21869670/</a></em></p>\n<p><em>McGarry ME, Williams WA 2nd, McColley SA. The demographics of adverse outcomes in cystic fibrosis. Pediatr Pulmonol. 2019;54 Suppl 3(Suppl 3):S74-S83. doi:10.1002/ppul.24434 : <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6857719/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6857719/</a></em></p>\n<p><em>Hendrickson BC, Donohoe C, Akmaev VR, et al. Differences in SMN1 allele frequencies among ethnic groups within North America. J Med Genet. 2009;46(9):641-644. doi:10.1136/jmg.2009.066969: <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729371/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729371/</a></em></p>\n", "score": 64 }, { "answer_id": 29281, "body": "<p>There's a myriad of adjustments that can improve patients' treatment if it's race-informed. As a very small but characteristic example, the 2021 European Society of Cardiology Guidelines for Heart Failure recommend considering hydralazine and isosorbide dinitrate <strong>only</strong> for patients self-identifying as Black.</p>\n<p><a href=\"https://i.stack.imgur.com/rgpgU.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/rgpgU.png\" alt=\"enter image description here\" /></a></p>\n<p>Reference: McDonagh TA et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J. 2021 Sep 21;42(36):3599-3726. doi: 10.1093/eurheartj/ehab368</p>\n", "score": 20 }, { "answer_id": 29285, "body": "<p>Here are some random examples:</p>\n<p><a href=\"https://www.uofmhealth.org/health-library/tv7879\" rel=\"noreferrer\">Ashkenazi Jewish Genetic Diseases</a></p>\n<blockquote>\n<p>Bloom syndrome.</p>\n<p>Canavan disease.</p>\n<p>Cystic fibrosis. Th</p>\n<p>Familial dysautonomia (FD).</p>\n<p>Fanconi anemia.</p>\n<p>Gaucher disease.</p>\n<p>Mucolipidosis IV.</p>\n<p>Niemann-Pick disease (type A).</p>\n<p>Tay-Sachs disease.</p>\n<p>Torsion dystonia.</p>\n</blockquote>\n<p><a href=\"https://en.wikipedia.org/wiki/Medical_genetics_of_Jews#Sephardi_and_Mizrahi_diseases\" rel=\"noreferrer\">Sephardi and Mizrahi Jews diseases</a></p>\n<blockquote>\n<p>Oculocutaneous albinism</p>\n<p>Ataxia telangiectasia</p>\n<p>Creutzfeldt–Jakob disease</p>\n<p>Cerebrotendinous xanthomatosis</p>\n<p>Cystinuria</p>\n<p>Familial Mediterranean fever</p>\n<p>Glycogen storage disease III</p>\n<p>Limb girdle muscular dystrophy</p>\n<p>Tay–Sachs</p>\n<p>11-β-hydroxylase deficiency</p>\n</blockquote>\n<p><a href=\"https://intermountainhealthcare.org/blogs/topics/live-well/2017/07/lactose-intolerance/#:%7E:text=African%20American%20and%20Asian%20ethnicities,they%20need%20for%20the%20day.\" rel=\"noreferrer\">Lactose Intolerance: Millions of Americans Don't Know They Have It</a></p>\n<blockquote>\n<p>African American and Asian ethnicities see a 75% - 95% lactose intolerance rate, while northern Europeans have a lower rate at 18% - 26% lactose intolerance</p>\n</blockquote>\n<p><a href=\"https://pubmed.ncbi.nlm.nih.gov/22643754/\" rel=\"noreferrer\">High lactose tolerance in North Europeans</a></p>\n<blockquote>\n<p>Lactose tolerance is exceptionally widespread in Northern European countries such as Sweden and Finland, with tolerance levels of 74% and 82%, respectively</p>\n</blockquote>\n", "score": 12 }, { "answer_id": 29282, "body": "<p>On a scale from sledgehammer to scalpel, race, as recorded in medical data is closer to sledgehammer in terms of granularity, but hey, sometimes we need sledgehammers (e.g. for broad epidemiological surveys).</p>\n<p>In terms of precision medicine, the promised dream is of identification of genetic idiosyncrasies guiding treatment - for which race is a very rough approximation.</p>\n<p>A counterexample to the utility of race in medicine is the very recent overturning of the use of race in estimated glomerular filtration rate (eGFR) calculation. Recently (as in this year, 2021), the national kidney foundation formed a task force to reassess the inclusion of race in eGFR calculation and recommended NOT including race as a factor.</p>\n<p><a href=\"https://www.kidney.org/news/update-reassessing-inclusion-race-diagnosing-kidney-diseases\" rel=\"nofollow noreferrer\">https://www.kidney.org/news/update-reassessing-inclusion-race-diagnosing-kidney-diseases</a></p>\n", "score": 4 }, { "answer_id": 29295, "body": "<p>The answer to your question can come from many angles. I do not have clinical experience, but I do have regulatory reporting experience.</p>\n<p>In the United States, the CDC runs a program called &quot;Vaccines for Children&quot;. I've had to run reports on demographics of patients many times, specifically for the following VFC criteria located at the link below.</p>\n<p><a href=\"https://www.cdc.gov/vaccines/programs/vfc/providers/questions/qa-flyer-hcp.html\" rel=\"nofollow noreferrer\">https://www.cdc.gov/vaccines/programs/vfc/providers/questions/qa-flyer-hcp.html</a></p>\n<p><strong>VFC Eligibility</strong></p>\n<p>Patients are eligible until they turn 19, if they meet one or more of the following criteria:</p>\n<ul>\n<li>Medicaid-eligible</li>\n<li>Uninsured</li>\n<li><strong>American Indian or Alaska Native (AI/AN)</strong></li>\n<li>Underinsured (Underinsured\nchildren can only be vaccinated at a Federally Qualified Health\nCenter (FQHC) or Rural Health Center (RHC)</li>\n</ul>\n<p>The medical record system I use refers to this data as the patient &quot;Ethnic Group&quot;.</p>\n<p><strong>Below is the relevant CMS regulation that states this information should be collected for those on Medicaid and CHIP. Many organizations will simply ask everyone during registration. If you're uncomfortable, you can simply decline to answer.</strong></p>\n<p><a href=\"https://www.medicaid.gov/medicaid/quality-of-care/quality-improvement-initiatives/quality-of-care-health-disparities/index.html\" rel=\"nofollow noreferrer\">https://www.medicaid.gov/medicaid/quality-of-care/quality-improvement-initiatives/quality-of-care-health-disparities/index.html</a></p>\n<p>*The Affordable Care Act of 2010 (Section 4302) requires the secretary of the Department of Health ad Human Services (HHS) to establish data collection standards for race, ethnicity, sex, primary language, and disability status, and calls for these categories to be consistently collected and reported in all national population health surveys that rely on self-report. Section 4302(b)(1) requires the collection of data on these five demographic characteristics in Medicaid and CHIP, and requires that the collection of these data in Medicaid and CHIP adhere to the data-collection standards developed in 4302(a). *</p>\n", "score": 3 }, { "answer_id": 29297, "body": "<p>When you immigrate to the United States (as I did), one of the first things you notice is that you get asked about your race <em>all the time</em>. Want a loan from your bank, your race is recorded (if you decide not to disclose your race, the bank officer will take a best guess - really) <a href=\"https://www.fdic.gov/resources/bankers/fair-lending/\" rel=\"nofollow noreferrer\">https://www.fdic.gov/resources/bankers/fair-lending/</a>. Apply to university, expect questions about race and ethnicity (<a href=\"https://stanfordmag.org/contents/race-and-admissions\" rel=\"nofollow noreferrer\">https://stanfordmag.org/contents/race-and-admissions</a>). And so on. Much like @Servaes pointed out in the comments, the US questions about race are (at least to me) rare outside of the US.</p>\n<p>The US is burdened with the history of slavery, post-slavery <em>Jim Crow</em> policy and some level of post-Jim-Crow systemic racism. There are now many laws that address and try to correct these injustices. However, in order to do that, they need to measure what's going on. That's the source of many of these questions in the US.</p>\n<p>And, of course, there are the specifics of race as a contributor to the likelihood of genetic conditions that the other answers address (personal example: after my wife's third miscarriage, my wife's Middle Eastern heritage and my French Canadian background suggested a Tay–Sachs test - <a href=\"https://www.ninds.nih.gov/Disorders/All-Disorders/Tay-Sachs-Disease-Information-Page\" rel=\"nofollow noreferrer\">https://www.ninds.nih.gov/Disorders/All-Disorders/Tay-Sachs-Disease-Information-Page</a>).</p>\n", "score": 3 }, { "answer_id": 29301, "body": "<p>In addition to all the fine answers, there are even more clinical reasons for including race in your chart. For one, clinical lab norms and calculations based on the clinical lab values can differ by race. For example, the calculation for Glomerular Filtration Rate, an important indicator of renal function, uses a different formula for African American patients inside the US (<a href=\"https://www.kidney.org/atoz/content/race-and-egfr-what-controversy\" rel=\"nofollow noreferrer\">https://www.kidney.org/atoz/content/race-and-egfr-what-controversy</a>). Note that this is not without controversy, as discussed in the link.</p>\n<p>There are also known biases in the output of pulse oximeters by skin color (<a href=\"https://www.nejm.org/doi/full/10.1056/nejmc2029240\" rel=\"nofollow noreferrer\">https://www.nejm.org/doi/full/10.1056/nejmc2029240</a>). Perhaps a situation can arise where a clinician is making an important therapeutic choice based on the numbers -- like whether a patient needs to be on a ventilator or not -- but isn't at the bedside. It might be nice to have race in the chart to determine how reliable the pulse oximeter numbers may or may not be.</p>\n", "score": 3 } ]

[ "epidemiology", "research", "genetic-predisposition", "race", "ethnicity" ]

[ { "answer_id": 5259, "body": "<blockquote>\n<p>Remember not to drink too soon before or after a meal as the water will dilute the digestive juices</p>\n</blockquote>\n<p>While that claim might <em>sound</em> reasonable at first, I doubt this has any effect you need to consider for your health. There's several reasons for this:</p>\n<ul>\n<li><p>The stomach normally contains about <a href=\"https://www.nlm.nih.gov/medlineplus/ency/article/003883.htm\" rel=\"noreferrer\">20 to 100 milliliters of stomach acid at a pH of around 2 to 3</a>. To change pH by one point, you need to dilute it 1:10. If the stomach contains 50 milliliters at a pH of 2, for example, half a litre is needed to get it up to a pH of 3.</p>\n<p>The effect definitely isn't negligible, but it's less than you might think because stomach acid is a very strong acid. An acid with a pH of 3 or even 4 is still a strong acid, and unlikely to cause problems - the medical condition of <a href=\"http://emedicine.medscape.com/article/170066-overview\" rel=\"noreferrer\">achlorhydria</a> is only diagnosed when the stomach acid pH is greater than 5 in men or 6.8 in women.</p>\n</li>\n<li><p>The stomach is capable of regulating pH if needed - for example, <a href=\"http://m.bja.oxfordjournals.org/content/70/1/6.short\" rel=\"noreferrer\">in a study on preoperative patients</a>, one group was allowed to drink water and one wasn't. The mean water intake was 400 milliliters for the group that was allowed to. The stomach acid in the two groups didn't differ significantly in either volume (which was just 20 milliliters) or acidity.</p>\n</li>\n</ul>\n<blockquote>\n<p>Drink water an hour after the meal to allow the body to absorb the nutrients.</p>\n</blockquote>\n<ul>\n<li><p>Food stays in the stomach for <a href=\"http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/basics/transit.html\" rel=\"noreferrer\">2 to 4 hours</a>, so the recommendation to wait one hour is weird. What's more, food itself contains water and thus does lower the acidity of the stomach - that's normal. Since it can be regulated (see above) it's very doubtful that a bit of water on top is going to screw things up</p>\n</li>\n<li><p>What do these sources think will happen with these nutrients? After the hours in the stomach, there's an additional 3 hours in the small intestine and <strong>30 to 40</strong> hours in the colon for the food. The colon and the stomach do have different roles in digestion, but in general, the digestive tract is pretty good at extracting nutrients from food</p>\n</li>\n</ul>\n<p>As a doctor writes <a href=\"http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/digestion/faq-20058348\" rel=\"noreferrer\">for the Mayo Clinic</a> (yes, I know that link is in your question):</p>\n<blockquote>\n<p>There's no concern that water will dilute the digestive juices or interfere with digestion.</p>\n</blockquote>\n<p>Drink water when you want to drink water. Also, don't trust sites that tell you to drink water to &quot;activate your internal organs&quot; in the morning ;-)</p>\n", "score": 17 } ]

[ "water", "time-of-day", "meal", "drinks", "diluting" ]

[ { "answer_id": 478, "body": "<p>In the blister shown, the likelihood of rupture is decreased because of the thickness of the epidermis on the palm of the hand, so you can leave it alone until the underlying area re-epithelializes. You'll know this is happening because of the decreased pain and the slow reabsorption of the fluid. Eventually you will just peal it off what's left of the blister, finding clean new skin underneath.</p>\n\n<p>But this is a great starting point for an answer about the treatment of blisters in general: is it better to leave them alone, drain the fluid, or de-roof them (take the top of the blister off)?</p>\n\n<p>There is <em>a lot</em> of disagreement about what constitutes the optimal treatment of blisters. Some background might be in order.</p>\n\n<p><img src=\"https://i.stack.imgur.com/2lJIv.jpg\" alt=\"enter image description here\"></p>\n\n<p>Blisters form when the upper layers of the epidermis separate from the lower layers, usually at the level of the stratum spinosum. At that level, the cells (because of proximity to the dermis, which contains the capillaries) have moisture in and between them. When the separation occurs, <em>sterile</em> fluid from the stratum spinosum oozes unopposed into the space between the layers, and a blister forms.</p>\n\n<p>The fluid, similar to plasma, contains molecules which may promote the rapid division which takes place in the stratum basale. This then differentiates into the upper layers of the epidermis and healing by new skin formation.</p>\n\n<blockquote>\n <p>Hydrostatic pressure causes the area of the separation to fill with a fluid that is similar in composition to plasma but has a lower protein level. About 6 hours after formation of the blister, cells in the blister base begin to take amino acids and nucleosides; at 24 hours, there is high mitotic activity in the basal cells; at 48 and 120 hours, new stratum granulosum and stratum corneum, respectively, can be seen.</p>\n</blockquote>\n\n<p>The <em>sterile</em> fluid is a very rich and inviting growth medium for bacteria. For this reason, some people think it should be removed. The denuded skin underneath has lost some of it's protection against infection. For this reason, some think the blister should be left intact. Between these two extremes are those who favor drainage of the fluid leaving the cover intact.</p>\n\n<p>To my thinking (and training), this is the worst option. Poking a hole in the blister, no matter how cleanly it's done, will leave a point of entry for bacteria (it doesn't take much). The bacteria will flourish in the moisture (which will still seep into the space) under the roof of the blister, protected from being washed away. This may (and often does) lead to an infection of the wound.</p>\n\n<p>It's much better to prevent infection than to treat it. </p>\n\n<p>The reasoning of either of the other camps is more supportable. I favor leaving the blister intact as long as possible, giving the underlying wound time to form new stratified protective epidermalis.</p>\n\n<p>Treatment by people in this camp consists of carefully cleaning and disinfecting the surface of the blister and the surrounding skin, and covering it loosely with protective padding, usually gauze, then wrapping the entire thing with gauze wrap. The patient is instructed to check the blister daily; if it \"pops\" or becomes cloudy, the roof must be removed (most people prefer to have this done by a doctor or nurse), the area cleaned to remove any bacteria which might have entered, and a sterile dressing (over a light application of an antibacterial cream) reapplied, and changes daily until healed.</p>\n\n<p>The opposite camp reasons that the blister will break anyway, so get it over with and get the sterile dressing on, then clean and redress (with a light application of an antibacterial cream) daily. Also, if the blister is tense, it may be impeding healing of the base by decreasing blood flow. The problem with this approach is that it hurts more than leaving it alone, and the risk of infection is still greater than if the blister is intact.</p>\n\n<p>Many studies have been done to try to determine the best approach. Common sense plays a role. If the blister is very delicate (as in a large, tense and fragile blister of a burn), or if it looks unstable, I'll remove the roof of the blister. If I think it can be preserved for even one or two days, I'll leave it on. Every day it's left on without infection is a day of healing and decreased pain as new skin is made.</p>\n\n<p>From one paper:</p>\n\n<blockquote>\n <p>There seems to be a paucity of good clinical evidence related to this subject, despite several review articles. The sole paper found involved a small sample, but showed infection rates to be higher if blisters are aspirated or deroofed, and that pain scores were higher in the group that underwent deroofing.</p>\n</blockquote>\n\n<p>From a pain point of view:</p>\n\n<blockquote>\n <p>aspiration appears to result in less pain than deroofing. (See above: also more infection.)</p>\n</blockquote>\n\n<p>The common sense comes in with type, size, and location of blister, reliability of care by the patient or their family, location or level of activity likely to cause rupture, or in the case of hikers' blisters (and others away from medical care), what the best model is to prevent infection while still using the involved area if necessary.</p>\n\n<p>Also changing the scene are the new available protective dressings of deroofed blisters that allow moist healing, non-occlusive protection and visibility of the underlying skin. </p>\n\n<p>_{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2564175/\" rel=\"noreferrer\">Management of burns blisters</a>}<br>\n_{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8570998\" rel=\"noreferrer\">Friction blisters. Pathophysiology, prevention and treatment.</a>} </p>\n", "score": 26 }, { "answer_id": 7, "body": "<p>Generally speaking, it's best to leave blisters undisturbed. Unroofing the blister completely is definitely ill-advised, as it exposes the entire dermis underneath, removing a primary barrier to infection. Cover it loosely with rolled gauze and leave it alone; it will either drain on its own, or reabsorb the fluid over time.</p>\n", "score": 14 }, { "answer_id": 157, "body": "<p>In first aid, we normally leave blisters alone. But there is one exception. In multi day walking events, there is a protocol to treat blisters.</p>\n\n<ol>\n<li>We clean the blister and the skin around in.</li>\n<li>We make it as sterile as possible</li>\n<li>Use a single use sterile needle to make two holes on each of the sides of the blister in walking direction.</li>\n<li>gently empty the blister, while collecting the fluid.</li>\n<li>Clean it again.</li>\n<li>Now you can use the right tape to cover the area. This can be tricky because each wrinkle kan lead to new blisters.</li>\n</ol>\n\n<p>If the blister is open or it contains blood, consult a medical professional.</p>\n", "score": 6 } ]

[ "wound", "removal" ]

[ { "answer_id": 490, "body": "<p>Using headphones at a sufficiently high volume level may cause cause trauma to cochlear structure in the inner ear which gives rise to temporary or permanent hearing impairment or <a href=\"http://en.wikipedia.org/wiki/Hearing_loss\" rel=\"noreferrer\">deafness</a>.</p>\n\n<p>Sound pressure is measured in <a href=\"http://en.wikipedia.org/wiki/Decibel\" rel=\"noreferrer\">decibels</a> and exposure to 75dB (even after long exposure) are usually safe. However, long or repeated to sounds at above 85dB can cause hearing loss. <strong>The louder the sound, the shorter the amount of time it takes for NIHL to happen.</strong></p>\n\n<p>The risk is higher especially in loud places as volume often needs to compete with the background noise. For example, the average sound level on a busy street is about 80dB. In the Airo study, when the outdoor noise was a mere 65dB, listeners raised headphone volume levels to over 80dB^{<a href=\"http://web.archive.org/web/19991117210432/http://hearnet.com/text/mainframe.html\" rel=\"noreferrer\">1997</a>}.</p>\n\n<p>This figure shows the average chosen listening levels for our subjects across the different background noise levels^{<a href=\"http://web.archive.org/web/20080807140756/http://www.hearingconservation.org/docs/virtualPressRoom/FligorIves.pdf\" rel=\"noreferrer\">2006</a>}:</p>\n\n<p><img src=\"https://i.stack.imgur.com/psOnGl.png\" alt=\"Average chosen listening level\"></p>\n\n<p>When we experience sound in our environment (TV, radio, traffic), normally these sounds are at safe levels, however long period of exposure to high sound pressure levels at high volume can be damaging to sensitive structures in the inner ear and cause noise-induced hearing loss (NIHL).</p>\n\n<p>The anatomy of hearing loss (simplified view):</p>\n\n<p><img src=\"https://i.stack.imgur.com/HGCCX.gif\" alt=\"Simplified View of Ear Structure\"></p>\n\n<p>Image credits: <a href=\"http://headwize.com/?page_id=266\" rel=\"noreferrer\">HeadWise</a></p>\n\n<p>Hearing damage from headphones is probably more common than from loudspeakers, even at comparable volumes, due to the close coupling of the transducers to the ears.</p>\n\n<p>Symptoms of hearing damage:</p>\n\n<ul>\n<li>Ringing or buzzing in the ears.</li>\n<li>Difficulty in understanding speech.</li>\n<li>Slight muffling of sounds.</li>\n<li>Difficulty understanding speech in noisy places or places with poor acoustics.</li>\n</ul>\n\n<h3>Recommendations</h3>\n\n<p>The WHO recommends that young people limit the use of personal audio player to one hour a day in an effort to limit exposure to noise.</p>\n\n<p>NIOSH recommends a safe headphone listening volume of 85dB. Although headphones are not sold with SPL meters, they can be purchased separately.</p>\n\n<blockquote>\n <p>One could note of the volume control setting that pumps out 85dB, any music recorded at a higher level would still play back at dangerous levels. The headphones would have to be recalibrated whenever the music changed.</p>\n</blockquote>\n\n<p>While in-the-ear earphones can produce higher sound levels than over-the-ear earphones, they are not necessarily used at higher levels.</p>\n\n<p><img src=\"https://i.stack.imgur.com/lrNwl.jpg\" alt=\"Maximum listening time per day using NIOSH damage-risk criteria.\"></p>\n\n<blockquote>\n <p>The table above shows NIOSH recommended maximum listening time per day, depending on the style of earphones used and the volume control settings on the player. On this chart, the “Isolator” style refers to earphones that have been reported to block out background noise, and “Supra-Aural” style refers to earphones that sit on top of the ear. The final column shows our measurements for the iPod, using the stock earbuds from Apple.</p>\n</blockquote>\n\n<hr>\n\n<p>Here are the average decibel ratings of some familiar sounds:</p>\n\n<ul>\n<li><p>45dB</p>\n\n<ul>\n<li>The humming of a refrigerator.</li>\n</ul></li>\n<li><p>60dB</p>\n\n<ul>\n<li>Normal everyday conversation.</li>\n<li>Ringing telephone.</li>\n<li>Normal piano practice.</li>\n</ul></li>\n<li><p>70dB</p>\n\n<ul>\n<li>Restaurant.</li>\n</ul></li>\n<li><p>80-85dB</p>\n\n<ul>\n<li>Heavy city traffic, alarm clock at 2 feet, factory noise, vacuum cleaner, garbage disposal.</li>\n</ul></li>\n<li><p>90-95dB</p>\n\n<ul>\n<li>Motorcyles.</li>\n<li>Subway trains, motorcycle, workshop tools, lawn mower.</li>\n</ul></li>\n<li><p>100-110dB</p>\n\n<ul>\n<li>An MP3 player at maximum volume.</li>\n<li>Dance club.</li>\n<li>Chain saw, pneumatic drill.</li>\n<li>Timpani &amp; bass drum rolls.</li>\n</ul></li>\n<li><p>120dB</p>\n\n<ul>\n<li>Sirens.</li>\n<li>Symphonic music peak. Rock concert speaker sound, sandblasting, thunderclap.</li>\n</ul></li>\n<li><p>130dB</p>\n\n<ul>\n<li>Jet take off.</li>\n<li>Gunfire.</li>\n</ul></li>\n<li><p>150dB</p>\n\n<ul>\n<li>Firecrackers and firearms.</li>\n<li>Rock music peak.</li>\n</ul></li>\n</ul>\n\n<p>The distance from the source of the sound and period of time are also important factors in protecting your hearing.</p>\n\n<hr>\n\n<p>Read also:</p>\n\n<ul>\n<li><p><a href=\"http://www.who.int/pbd/deafness/activities/IECD_2015_Press_Release_EN.pdf\" rel=\"noreferrer\">1.1 billion people at risk of hearing loss - WHO highlights serious threat posed by exposure to recreational noise</a></p>\n\n<blockquote>\n <p>Data from studies in middle- and high-income countries analysed by WHO indicate that among teenagers and young adults aged 12-35 years, nearly 50% are exposed to unsafe levels of sound from the use of personal audio devices and around 40% are exposed to potentially damaging levels of sound at entertainment venues. Unsafe levels of sounds can be, for example, exposure to in excess of 85 decibels (dB) for eight hours or 100 dB for 15 minutes. </p>\n \n <p>Teenagers and young people can better protect their hearing by keeping the volume down on personal audio devices, wearing earplugs when visiting noisy venues, and using carefully fitted, and, if possible, noise-cancelling earphones/headphones. They can also limit the time spent engaged in noisy activities by taking short listening breaks and restricting the daily use of personal audio devices to less than one hour. With the help of smartphone apps, they can monitor safe listening levels</p>\n</blockquote></li>\n<li><p><a href=\"http://www.asha.org/public/hearing/disorders/causes_adults.htm\" rel=\"noreferrer\">Causes of Hearing Loss in Adults</a> at ASHA</p>\n\n<blockquote>\n <p>Very loud noise can cause permanent hearing loss. This is called noise-induced hearing loss. Listening to loud noise for long periods of time can damage the hair cells in the inner ear. Noise-induced hearing loss usually develops gradually and painlessly. A single exposure to an extremely loud sound such as an explosion can cause a sudden loss of hearing. This is called acoustic trauma.</p>\n</blockquote></li>\n<li><p><a href=\"http://www.nidcd.nih.gov/health/hearing/pages/noise.aspx\" rel=\"noreferrer\">Noise-Induced Hearing Loss</a> at NIDCD</p></li>\n<li><a href=\"http://headwize.com/?page_id=266\" rel=\"noreferrer\">Preventing Hearing Damage When Listening With Headphones</a> <a href=\"http://media.paisley.ac.uk/~campbell/ASP/Preventing%20Hearing%20Damage%20When%20Listening%20With%20Headphones.doc\" rel=\"noreferrer\">(DOC)</a> at HeadWise</li>\n<li><a href=\"http://hearinglossweb.com/\" rel=\"noreferrer\">Hearing Loss Web</a> site</li>\n<li><a href=\"http://web.archive.org/web/20080807140756/http://www.hearingconservation.org/docs/virtualPressRoom/FligorIves.pdf\" rel=\"noreferrer\">(PDF) \"Does earphone type affect risk for recreational noise-induced hearing loss?\"</a> Brian J. Fligor, Sc.D., CCC-A and Terri Ives, Sc.D, 2006</li>\n<li><a href=\"http://web.archive.org/web/20080726181956/http://www.hearingconservation.org/docs/virtualPressRoom/portnuff.htm\" rel=\"noreferrer\">\"Sound Output Levels of the iPod and Other MP3 Players: Is There Potential Risk to Hearing?\"</a> Cory D. F. Portnuff and Brian J. Fligor, Sc.D., CCC-A, 2006</li>\n<li><p><a href=\"https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&amp;p_id=9735\" rel=\"noreferrer\">Occupational noise exposure</a> at OSHA</p>\n\n<blockquote>\n <p>When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, rather than the individual effect of each.</p>\n</blockquote></li>\n<li><p><a href=\"http://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves\" rel=\"noreferrer\">The Fletcher–Munson curves</a> at Wikipedia</p></li>\n</ul>\n", "score": 12 }, { "answer_id": 7574, "body": "<p>The answer to this is really not known. The field of audiology now talks about \"hidden hearing loss\". This is hearing loss than does not show up in clinical tests. <a href=\"http://www.jneurosci.org/content/29/45/14077.full\" rel=\"nofollow\">Kujawa and Liberman (2009)</a> found in animal models that sound exposure that has only a temporary affect on the ability of the animal to detect quick sounds, can do permanent damage.</p>\n\n<p><a href=\"http://journals.lww.com/ear-hearing/Abstract/2012/11000/Digital_Music_Exposure_Reliably_Induces_Temporary.10.aspx\" rel=\"nofollow\">Le Prell et al.</a> looked at this in humans. These are difficult studies to do since you do not want to harm otherwise healthy research subjects. She had subjects listen to music at 94, 99, and 101 dB A for 4 hours. For the 94 dB A group, there was no statistically reliable effects on hearing 15 minutes after stopping the music (ask quick as they could measure anything). For 101 dB A, the effect lasted over a day, but less than a week. It is thought that the 101-dB A 4-hr exposure is safe, but know one really knows yet. Further, the effect of repeated exposures (either before or after recovery) is not known.</p>\n\n<p>What is known is that there is no way to reverse hearing loss. There is no pill you can take. While hearing aids do restore some level of hearing, you should take care of your ears.</p>\n", "score": 3 } ]

[ "hearing" ]

[ { "answer_id": 503, "body": "<p><strong>Surprisingly, no</strong>. Hot water does kill bacteria, but what's comfortable for your hands is also pretty comfortable for bacteria. Most pathogens start to die off around 60°C to 70°C (140°F to 158°F)^{<a href=\"http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-2-the-pre-travel-consultation/water-disinfection-for-travelers\">1</a>}, but water from the \"hot\" tap in a sink is typically below that (40° to 55°C or 104° to 131°F)^{<a href=\"http://news.nationalgeographic.com/news/energy/2013/12/131213-washing-hands-hot-water-wastes-energy-health/\">2</a>}. In order to kill bacteria, the water would have to be way too hot for you to tolerate.</p>\n\n<p>According to National Geographic, in <a href=\"http://news.nationalgeographic.com/news/energy/2013/12/131213-washing-hands-hot-water-wastes-energy-health/\">Washing Hands in Hot Water Wastes Energy</a>:</p>\n\n<blockquote>\n <p>Carrico said that after a review of the scientific literature, her team found \"no evidence that using hot water that a person could stand would have any benefit in killing bacteria.\" Even water as cold as 40°F (4.4°C) appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed, and dried properly.</p>\n</blockquote>\n\n<p>This agrees with the World Health Organization's conclusion^{<a href=\"http://whqlibdoc.who.int/publications/2009/9789241597906_eng.pdf\">3</a>}:</p>\n\n<blockquote>\n <p><strong>Water temperature</strong> -\n Apart from the issue of skin tolerance and level of comfort,\n water temperature does not appear to be a critical factor for\n microbial removal from hands being washed. In contrast, in a\n study comparing water temperatures of 4 °C, 20 °C and 40 °C,\n warmer temperatures have been shown to be very significantly\n associated with skin irritation. The use of very hot water for\n handwashing should therefore be avoided as it increases the\n likelihood of skin damage.</p>\n</blockquote>\n\n<p>There are a number of studies that have looked into water temperature and handwashing and concluded that there is little to no added benefit to washing with hotter water, for example:</p>\n\n<ul>\n<li><p><a href=\"http://onlinelibrary.wiley.com/doi/10.1046/j.1471-5740.2002.00043.x/full\">Water temperature as a factor in handwashing efficacy.</a>. Michaels, B., Gangar, V., Schultz, A., Arenas, M., Curiale, M., Ayers, T. and Paulson, D. (2002), Food Service Technology, 2: 139–149</p></li>\n<li><p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23814480\">The Environmental Cost of Misinformation: Why the Recommendation to Use Elevated Temperatures for Handwashing is Problematic.</a>\nCarrico AR, Spoden M, Wallston KA, Vandenbergh MP.\nInt J Consum Stud. 2013 Jul 1;37(4):433-441. (This study examines <em>beliefs</em> about handwashing and unintended economic or climate effects, rather than water temperature directly.)</p></li>\n</ul>\n\n<h2>It's all about the technique</h2>\n\n<p>The CDC recommends <strong>using soap</strong>, <strong>scrubbing</strong> for at least 20 seconds, and <strong>rinsing</strong> under running water^{<a href=\"http://www.cdc.gov/handwashing/show-me-the-science-handwashing.html\">4</a>}. Based on the currently available scientific literature, it does not recommend using hotter water, as it does not seem to have an effect.</p>\n\n<p>In short, scrubbing and using soap are far more effective for hand-washing than using hot water is.</p>\n", "score": 22 }, { "answer_id": 23011, "body": "<p>They weren't entirely wrong. Saying that warm water kills germs better isn't true, but warm water is good for getting rid of dirt, grime, and oils. It works in the same way as dissolving sugar in water. Heat causes partials to move faster which increases the chance of a collision and therefore the rate at which molecules bond. So in the end, warm water is still the better option even if it doesn't kill germs.\n<a href=\"https://www.chemguide.co.uk/physical/basicrates/introduction.html#top\" rel=\"nofollow noreferrer\">https://www.chemguide.co.uk/physical/basicrates/introduction.html#top</a>\n<a href=\"https://www.chemguide.co.uk/physical/basicrates/temperature.html\" rel=\"nofollow noreferrer\">https://www.chemguide.co.uk/physical/basicrates/temperature.html</a></p>\n", "score": 3 } ]

[ "water" ]

[ { "answer_id": 3095, "body": "<p>Steve Pavlina did an experiment on himself for testing the Polyphasic Sleep. On his blog there is a lot of information about the experiment.\n<a href=\"http://www.stevepavlina.com/blog/2005/10/polyphasic-sleep/\" rel=\"nofollow\">http://www.stevepavlina.com/blog/2005/10/polyphasic-sleep/</a></p>\n\n<p>However, what is written on his blog is not scientific proof, but from his own perspective.</p>\n\n<p>As he wrote on his blog:</p>\n\n<blockquote>\n <p>This is a treasure trove of free information for anyone interested in learning about my trial of polyphasic sleep. To my knowledge these are the most detailed polyphasic sleep logs you’ll be able to find anywhere on the web.</p>\n</blockquote>\n", "score": 3 } ]

[ "sleep" ]

[ { "answer_id": 751, "body": "<p>The typical scenario of a seizure is:</p>\n\n<ol>\n<li>loss of consciousness</li>\n<li>uncontrolled movements</li>\n<li>recovery</li>\n</ol>\n\n<p>The conduct to adopt during each of these phases follows:</p>\n\n<h2>During 1. and 2.</h2>\n\n<p>The person will fall on the ground if standing and may get hurt, either due to the fall or due to the uncontrolled movements that will follow.</p>\n\n<p><strong>The only things you can (and should) do at that stage</strong> are:</p>\n\n<ul>\n<li>If possible, <strong>ease the victim to the floor</strong> when falling, without restricting his/her movements. Be careful for yourself. Do not face the person (you could get punched, and even a thin person is very strong in such cases), stand on his/her back.</li>\n<li><strong>Should the victim wear eyeglasses, remove them carefully</strong>. If you can, carefully loosen clothes or jewellery around the neck.</li>\n<li><strong>Insert a cushion or some folded clothes under the victim's head</strong>. Here again, be careful not being hit and do not restrict the victim's movements.</li>\n<li><strong>Clear the area</strong>: remove any object that can be dangerous for the victim. </li>\n<li><strong>Be calm and reassuring for people around</strong>. Ask them to stay away from the victim, or to go next room should this happen inside a building. Ask at least one to stay at your disposal in case of need. This may be useful later.</li>\n<li><strong>Monitor how long this phase lasts</strong>.</li>\n<li>If you're not aware of the victim's history with seizure, try to find any card or jewellery mentioning it.</li>\n</ul>\n\n<p>There are things <strong>you should absolutely avoid doing</strong> as they would do way more bad than good:</p>\n\n<ul>\n<li><strong>DO NOT hold the victim or restrain his/her movements.</strong> The victim may hurt him/herself, the only thing you should do is to secure the area as much as you can (see above).</li>\n<li><strong>DO NOT insert anything into the victim's mouth.</strong> The victim is NOT going to swallow his/her tongue. </li>\n<li><strong>DO NOT try to make the victim bite anything.</strong> No belt, no pencil, nothing. The victim may bite his/her own tongue, you cannot and should not try to prevent that.</li>\n<li><strong>DO NOT move the victim</strong>, unless there is an immediate, real, and out-of-control danger.</li>\n<li><strong>DO NOT leave the victim on his/her own.</strong> Don't stay too close, though. Be careful for yourself and get ready to do some more securing should this be needed.</li>\n</ul>\n\n<h2>During 3.</h2>\n\n<p>The victim will not necessarily be aware of what happened, and will need time to recover. He/she might be disoriented/confused, and he/she may have lost urine during the previous phase. You should calmly expect both signs.</p>\n\n<p>There are some do's and don't here, as well:</p>\n\n<p><strong>Do:</strong></p>\n\n<ul>\n<li><strong>Gently put the victim in recovery position</strong> (on a side: <a href=\"http://www.nhs.uk/Conditions/Accidents-and-first-aid/Pages/The-recovery-position.aspx\" rel=\"noreferrer\">video and explanations here</a>). </li>\n<li>As long as the victim has not recovered consciousness, <strong>ensure the victim still breathes</strong>. To do this, approach your ear to his/her mouth, while looking at his/her chest, for 10 seconds. This allows you to hear the sound of breathing, feel his/her breath, and see the movements of his/her chest. <strong>Should you perceive none of these that's a medical emergency</strong> (potential cardiac arrest, which is another question¹) - This is quite unlikely to happen but you have to check.</li>\n<li><strong>Without being intrusive</strong>, visually check whether urine seems to appear on the person's clothes. <strong>Failing to determine this is not a problem.</strong></li>\n<li>During the recovery, <strong>speak calmly, be friendly and gentle</strong>. </li>\n<li>Once the victim has regained enough consciousness, <strong>explain what happened and be reassuring</strong>.</li>\n<li><strong>Ask the victim to show his/her tongue, and explain why</strong>. He/she can be hurt without knowing.</li>\n</ul>\n\n<p><strong>Depending on what you know or discovered regarding the victim's history with seizure, and depending on the time the previous phase lasted, you may have to call the medical emergency services</strong>:</p>\n\n<ul>\n<li>Should the last phase (1. + 2.) have lasted more than 5 minutes</li>\n<li>Should this be the first time the person has a seizure</li>\n<li>Should the person have stopped breathing</li>\n<li>Should another loss of consciousness occurs </li>\n<li>Should another series of uncontrolled movements occurs</li>\n<li>Should the person remain disoriented after a few minutes of recovery</li>\n<li>Should the person be aggressive/violent</li>\n<li>Should the person be hurt </li>\n<li>Should the person be a pregnant woman</li>\n<li>Should the person ask you to call the emergency services</li>\n<li>Or <strong>should you have any doubt</strong>, assume you should call the emergency medical services.</li>\n</ul>\n\n<p><strong>When calling the medical emergency services</strong>, </p>\n\n<ul>\n<li>Don't be in a hurry, stay calm.</li>\n<li>Tell your name, phone number, current location,</li>\n<li>Tell this is for a seizure, and tell the victim's gender and age</li>\n<li>Describe the victim's condition, tell what of the above makes you call, tell whether there is a loss of urine or any injury.</li>\n<li>They will guide you. Do whatever they tell you and answer any question.</li>\n<li><strong>Do NOT hang up the phone before instructed to do so</strong></li>\n</ul>\n\n<p><strong>Should no emergency call be needed</strong>, offer some help to the person: </p>\n\n<ul>\n<li>Lead him/her away from any danger, a quiet bench nearby is appropriate should you be outside. </li>\n<li>Offer him/her to call a friend, a relative or a cab.</li>\n<li>In the US, and probably in some other countries, it's illegal to drive within 6 months after having had an unexplained seizure (not caused by eclampsia, hypoxia, head injury, etc.). Should this be the case, you don't have to force the person not to drive, but you can strongly discourage it.</li>\n</ul>\n\n<p><strong>Don't:</strong></p>\n\n<ul>\n<li><strong>Don't speak fast</strong> or act in any way that could frighten the victim. Keep in mind the recovery phase is a slow process during which the victim feels dizzy and confused.</li>\n<li><strong>Don't propose water or food before complete recovery or if you had to call the medical emergency services.</strong> In this last case, ask them whether you can propose anything.</li>\n</ul>\n\n<hr>\n\n<p>^{1- Being nonresponsive and not breathing triggers the <a href=\"http://en.wikipedia.org/wiki/Cardiopulmonary_resuscitation\" rel=\"noreferrer\">CPR process</a>. It is not described here as it is a question on its own.}</p>\n\n<hr>\n\n<p>References:</p>\n\n<ul>\n<li><a href=\"https://www.google.fr/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=4&amp;cad=rja&amp;uact=8&amp;sqi=2&amp;ved=0CFcQFjAD&amp;url=http%3A%2F%2Fwww.interieur.gouv.fr%2Fcontent%2Fdownload%2F36645%2F277100%2Ffile%2FPSC1_version%25201.1.1.pdf&amp;ei=-Vo_VcHwF_Cf7gbIx4CIBg&amp;usg=AFQjCNEy-sRV1JA6qrwjNaMT2Hk6_9D7ZA&amp;sig2=L5jX6wAjZl4xKxzvI8YF-w&amp;bvm=bv.91665533,d.bGQ\" rel=\"noreferrer\">Premiers Secours civiques 1</a> (First-aid guidelines for general public), Ministry of Interior, France</li>\n<li><a href=\"http://www.cdc.gov/epilepsy/basics/first_aid.htm\" rel=\"noreferrer\">First-aid for seizures</a>, Centers for Disease Control and Prevention, Atlanta, USA</li>\n<li><a href=\"https://www.epilepsy.org.uk/info/firstaid\" rel=\"noreferrer\">What to do when someone has a seizure</a>, the British Epilepsy Action Charity, Leeds, UK </li>\n</ul>\n", "score": 26 } ]

[ "first-aid", "neurology", "seizure" ]

[ { "answer_id": 18234, "body": "<p>The previous answer does not refer to clinical studies so I thought I would have a look.</p>\n\n<p>TLDR; the clinical studies I've seen suggest not to rinse with water after brushing.\n<hr>\nAccording to <a href=\"https://doi.org/10.1007/s41894-018-0025-5\" rel=\"noreferrer\">Doméjean, et al. (2018)</a>, you should not rinse after brushing.</p>\n\n<blockquote>\n <p>For maximizing the topical effect of the fluoride toothpaste, patients should be encouraged to spit out excess toothpaste and not rinse with water after brushing (<a href=\"https://doi.org/10.1007/s41894-018-0025-5\" rel=\"noreferrer\">Doméjean, et al. 2018</a>).</p>\n</blockquote>\n\n<p><a href=\"https://doi.org/10.1159/000016540\" rel=\"noreferrer\">Ashley, et al. (1999)</a> looked at the DMFT (Decayed, Missing or Filled Teeth) levels for rinsing with water and no rinsing, and the DMFT levels were lower amongst those who rinsed by other methods or did not rinse after brushing. However, those who claimed not to rinse had a lower mean DMFT than the other subjects, which was <em>\"on the borderline of significance\"</em>.</p>\n\n<blockquote>\n <p>The mean DMFT of the 1,137 subjects who rinsed with a cup or beaker of water after brushing was significantly higher (mean 3.97, SD 3.74) than those who rinsed by other methods or did not rinse (mean 3.61, SD 3.79, p= 0.012, table 1). This represents a 9% difference in DMFT when compared with those who did not use a beaker. The 69 (2%) who claimed not to rinse had a lower mean DMFT (2.91, SD 3.24) than the other subjects, which was on the borderline of significance (p= 0.063) (<a href=\"https://doi.org/10.1159/000016540\" rel=\"noreferrer\">Ashley, et al. 1999</a>)</p>\n</blockquote>\n\n<p>So to answer your question</p>\n\n<blockquote>\n <p>Should we rinse with water after brushing our teeth?</p>\n</blockquote>\n\n<p>Looking at the DMFT levels after rinsing with water compared to not, and looking at <a href=\"https://doi.org/10.1007/s41894-018-0025-5\" rel=\"noreferrer\">Doméjean, et al. (2018)</a>, <strong>the clinical studies suggest not to rinse with water after brushing</strong></p>\n\n<h2>References</h2>\n\n<p>Ashley, P. F., Attrill, D. C., Ellwood, R. P., Worthington, H. V., &amp; Davies, R. M. (1999). Toothbrushing habits and caries experience. <em>Caries research, 33</em>(5), 401-402. doi: <a href=\"https://doi.org/10.1159/000016540\" rel=\"noreferrer\">10.1159/000016540</a></p>\n\n<p>Doméjean, S., Muller-Bolla, M., &amp; Featherstone, J. D. (2018). Caries preventive therapy. <em>Clinical Dentistry Reviewed, 2</em>(1), 14. doi: <a href=\"https://doi.org/10.1007/s41894-018-0025-5\" rel=\"noreferrer\">10.1007/s41894-018-0025-5</a></p>\n", "score": 7 }, { "answer_id": 21184, "body": "<h2>Summary:</h2>\n\n<ul>\n<li>Not rinsing after tooth brushing may somewhat increase the effectiveness of fluoridated toothpaste, but the evidence is inconsistent and the effect can vary greatly among individuals.</li>\n<li><a href=\"http://www.oralanswers.com/rinse-after-brushing/\" rel=\"nofollow noreferrer\">One possible explanation</a> for inconsistent effect: not rinsing after brushing appears to be only beneficial if you are at a high risk of getting cavities.</li>\n<li>Researchers and dental experts usually do not mention any time to wait before rinsing.</li>\n<li><a href=\"https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1741-2358.2001.00015.x\" rel=\"nofollow noreferrer\">Some authors</a> recommend a single brief slurry rinse. This can remove the toothpaste from the tongue and cheeks and greatly reduce the unpleasant aftertaste of the toothpaste, while still keeping the fluoride on the teeth.</li>\n</ul>\n\n<h2>Evidence:</h2>\n\n<p><strong>1)</strong> <a href=\"https://www.researchgate.net/publication/224005110_Post-brushing_rinsing_for_the_control_of_dental_caries_Exploration_of_the_available_evidence_to_establish_what_advice_we_should_give_our_patients\" rel=\"nofollow noreferrer\">Post-brushing rinsing for the control of dental caries: exploration of the available \nevidence to establish what advice we should give our patients, British Dental Journal, 2012</a></p>\n\n<p>The opinion of participants of the 2012 meeting between the authors and other \nexperts in the UK:</p>\n\n<blockquote>\n <p>Rinsing with water after brushing with fluoride toothpaste can reduce\n the benefit of fluoride toothpaste.</p>\n \n <p>Post-tooth brushing rinsing behaviours have the potential to <strong>either\n reduce or enhance the effectiveness of fluoride toothpaste</strong> and show\n <strong>wide variation in the general population.</strong> There is a lack of\n high-quality evidence to support definitive guidance in this area.</p>\n</blockquote>\n\n<p><strong>2)</strong> <a href=\"https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1741-2358.2001.00015.x\" rel=\"nofollow noreferrer\">The influence of rinsing routines on fluoride retention after toothbrushing (Gerodontology, 2001)</a>:</p>\n\n<blockquote>\n <p>It is suggested that for maximal effect, brushing with fluoride\n toothpaste should be followed by <strong>one brief slurry rinse,</strong> at the\n convenience and comfort of the patient/user.</p>\n</blockquote>\n\n<p><strong>3)</strong> <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12399689\" rel=\"nofollow noreferrer\">Prospective study of the effect of post-brushing rinsing behaviour on dental caries (Caries Research, 2002)</a></p>\n\n<blockquote>\n <p>A 3-year clinical trial of daily supervised brushing with fluoride\n toothpaste at school was used to test the effect of post-brushing\n rinsing with water on caries increment. A total of 407 children, mean\n age 11.8 years, attending three schools in Kaunas, Lithuania were\n enrolled following informed consent of the children and their parents.\n Caries was recorded at baseline and annually for 3 years. During the\n study, children in two schools (A and B) performed daily supervised\n brushing with a 1,500-ppm fluoride toothpaste. <strong>Children in school A\n rinsed their mouths thoroughly with a beaker of water after\n toothbrushing whereas children in school B were only permitted to spit\n out once after brushing.</strong> Furthermore, the children in these schools\n were supplied with toothpaste and toothbrushes for use at home and in\n school. A third school (C), without daily brushing and without supply\n of toothpaste, served as control. Compliance with the protocol was\n consistently better in school B. After 3 years 276 children were\n available for examination. Three-year DMFS increments, including\n non-cavitated lesions (mean, 95% CI), were: school A, 6.8 (5.3; 8.3);\n school B, 6.2 (4.6; 7.8), and school C, 12.4 (10.6; 14.1). Mean\n increments for schools A and B did not differ significantly but were\n both significantly lower than those of school C (p&lt; 0.001). It is\n concluded that post-brushing <strong>rinsing with water, under the\n conditions of this study, does not significantly affect the caries\n reducing effect of a fluoride toothpaste.</strong></p>\n</blockquote>\n\n<p><strong>4)</strong> <a href=\"https://www.karger.com/Article/Abstract/16540\" rel=\"nofollow noreferrer\">Toothbrushing habits and caries experience (Caries Research, 1999)</a></p>\n\n<blockquote>\n <p>The mean DMFT of the 1,137 subjects who rinsed with a cup or beaker of\n water after brushing was significantly higher (mean <strong>3.97</strong>, SD 3.74)\n than those who rinsed by other methods or did not rinse (mean <strong>3.61</strong>, SD\n 3.79, p= 0.012, table 1). This represents a 9% difference in DMFT when compared with those who did not use a beaker. The 69 (2%) who claimed\n not to rinse had a lower mean DMFT (2.91, SD 3.24) than the other\n subjects, which was on the borderline of significance (p= 0.063).</p>\n</blockquote>\n", "score": 2 }, { "answer_id": 2016, "body": "<p>Rising removes the material the toothbrush detached. I see no reason NOT to rinse. The main use of tooth paste is actually to provide a suspension where the food and other particles can be incorporated during brushing. If you don't rinse, they will deposit again.</p>\n\n<p>Source: <a href=\"https://www.choice.com.au/health-and-body/dentists-and-dental-care/dental-products/articles/toothpaste-whats-the-difference\" rel=\"nofollow\">https://www.choice.com.au/health-and-body/dentists-and-dental-care/dental-products/articles/toothpaste-whats-the-difference</a> \"Tartar is the build-up of hardened plaque that can lead to gum disease. Although regular brushing can minimise its build-up, tartar can only be properly removed by a dentist. Of the toothpastes we looked at, almost all contain a tartar suspension agent – the most common being pyrophosphates and xanthan gum – designed to suspend tartar particles in saliva and prevent them from clinging to teeth.\"</p>\n\n<p>Other source: <a href=\"http://www.stab-iitb.org/newton-mirror/askasci/chem03/chem03188.htm\" rel=\"nofollow\">http://www.stab-iitb.org/newton-mirror/askasci/chem03/chem03188.htm</a></p>\n", "score": 0 } ]

[ "toothbrush", "toothpaste", "fluoride", "gargling-gargle", "rinsing-mouth" ]

[ { "answer_id": 13739, "body": "<p>Products high in calcium and magnesium should not be taken at the same time as antibiotics of the tetracycline (tetracycline, doxicycline, etc.) class, and milk should also be avoided with the quinolone class. They have the ability to bind the antibiotic in the gut, decreasing absorption. <strong>There is no reason to avoid dairy products while taking other antibiotics</strong> (such as the penicillin class, the one you're taking. The clavulanic acid is to increase it's strength against certain bacteria.) If the antibiotic package insert (or the pharmacists's instruction sheet) states it should be taken on an empty stomach, take it with water. But what you eat when you eat is your choice.</p>\n\n<p>Some doctors believe that milk products cause increased production or thickening of secretions, and that's a problem if you have a middle ear infection. If there is fluid in the middle ear, especially infected fluid, you want the fluid to drain out of the middle ear via the eustacian tube into the back of your throat. So, the thinking that milk makes mucus worse means recommending a decrease in milk products.</p>\n\n<p>Is that thinking correct? Probably not. Milk does not affect mucous production or quality.</p>\n\n<p>In one study of 60 volunteers,</p>\n\n<blockquote>\n <p>We conclude that no statistically significant overall association can be detected between milk and dairy product intake and symptoms of mucus production in healthy adults, either asymptomatic or symptomatic, with rhinovirus infection.</p>\n</blockquote>\n\n<p>This has been confirmed in other studies as well. In a subset of asthmatic patients, cessation of milk consumption improved symptomatology, but this is thought to be due to an allergy to a component of milk.</p>\n\n<hr>\n\n<p>The advice to eat yogurt is in all likelihood an attempt to reduce the risk of C. diff (aka Antibiotic Associated Diarrhea), which is present with any antibiotic. Antibiotics upset gut flora. Live culture yogurt has some beneficial gut bacteria species. However, this, too, depends on the yogurt. Probiotics <em>are</em> helpful, but many yogurts are monocultures and/or don't contain enough bacteria to make a difference to the gut. Some do, however. So, the advice to eat yogurt is good; it may not help, but it might. Look for yogurt with live cultures (plural).</p>\n\n<p>One meta analysis looked at research done on this very topic (which is hot in medicine right now.)</p>\n\n<blockquote>\n <p>Antibiotic-associated diarrhoea can be attributed in part to imbalances in intestinal microflora. Therefore, probiotic preparations are used to prevent this diarrhoea. </p>\n</blockquote>\n\n<p>It concluded,</p>\n\n<blockquote>\n <p>The results suggest a strong benefit of probiotic administration on antibiotic-associated diarrhoea, but further data are needed. The evidence for beneficial effects is still not definitive. Published studies are flawed by the lack of a placebo design and by peculiar population features.</p>\n</blockquote>\n\n<p>Personally, whenever I put patients on antibiotics, I also <em>prescribed</em> two yogurt brands, one serving of one in the morning and another serving of the second in the evening. The brands I recommended were shown to have sufficient CFUs (colony forming units) of several important beneficial gut inhabitants. (There weren't any single yogurt brand that had the big five.)</p>\n\n<p>_{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/2154152\" rel=\"noreferrer\">Relationship between milk intake and mucus production in adult volunteers challenged with rhinovirus-2.</a>}<br>\n_{<a href=\"http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2036.2002.01318.x/full\" rel=\"noreferrer\">Meta-analysis: the effect of probiotic administration on antibiotic-associated diarrhoea</a>} </p>\n", "score": 37 }, { "answer_id": 13736, "body": "<p>This is most commonly a precaution to prevent Mal-absorption. Milk has copious amounts of calcium which bond with the antibiotic in the gut. Once the tetracycline (antibiotic) bonds, it creates a neutral environment for food to digest in. Once the calcium bonds with mil it breaks down the antibiotic as well as the stomach acid used to break it down.This will not only cause Mal-absorption of nutrients through your G.I. tract, but will also keep your body from breaking down the medication as efficiently or at all. Gastroparesis in combination with tetracycline is also sometimes reported, dairy products could exacerbate this, but this was out of an old medical journal, I don't know the validity of that so take it with a grain of salt.. High calcium foods should be avoided while on treatment. </p>\n\n<p>There's the breakdown of why you shouldn't take them in combination.</p>\n\n<p>Here's more information on what to avoid and why.</p>\n\n<p><a href=\"https://medlineplus.gov/druginfo/meds/a682098.html\" rel=\"noreferrer\">https://medlineplus.gov/druginfo/meds/a682098.html</a></p>\n", "score": 6 } ]

[ "medications", "gastroenterology", "antibiotics", "milk", "gut-microbiota-flora" ]

[ { "answer_id": 413, "body": "<p>Overall, there has been inconsistent data on the effects of using zinc lozenges to treat the common cold. Most studies have also been done on children, which may lead to more uncertainty about its effects on adults, but some of the studies I will mention have been tested on adults. </p>\n\n<p>One study showed the effects of using zinc to prevent the common cold in schoolchildren. They found that between the two groups they studied (one took zinc sulfate tablets, the other placebos) that the zinc-supplemented group had less of a chance of getting the cold. They concluded that zinc supplements have a beneficial effect on children.^{<a href=\"http://ijp.tums.ac.ir/index.php/ijp/article/viewArticle/928\" rel=\"nofollow noreferrer\">1</a>}</p>\n\n<p>Another study (done by the same researchers as the second study I linked to) tested the effects of zinc lozenges on treating cold symptoms. They found that taking zinc lozenges within 24 hours of first getting cold symptoms may reduce the length of the cold. They do not give any firm recommendation though, because of insufficient data. They also mention the same side-effects as above.^{<a href=\"http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001364.pub4/abstract\" rel=\"nofollow noreferrer\">2</a>} This study is also backed up by other similar study which found that zinc lozenges reduced the duration of colds by about 7 days, again with only minor side effects such as bad taste and mouth irritation.^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/6367635\" rel=\"nofollow noreferrer\">3</a>} Other similar reports' results showed that zinc lozenges not only reduce the duration of colds, but also the severity.^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18279051?dopt=Abstract\" rel=\"nofollow noreferrer\">4</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15496046?dopt=Abstract\" rel=\"nofollow noreferrer\">5</a>}</p>\n\n<p>Some studies say that zinc lozenges do not have any noteworthy therapeutic effect in treating the common cold.^{<a href=\"http://aac.asm.org/content/31/8/1183.abstract?ijkey=c54e7d9e7cfc347b5eb4aca02fe68276ebe7863b&amp;keytype2=tf_ipsecsha\" rel=\"nofollow noreferrer\">6</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11073753?dopt=Abstract\" rel=\"nofollow noreferrer\">7</a>}</p>\n\n<p><strong>Should you take zinc lozenges?</strong></p>\n\n<p>No studies have provided sufficient information to prove or disprove beneficial effects of taking zinc lozenges to prevent and treat the common cold. The consumption of zinc lozenges doesn't present any dangerous or deadly effects, unless you consider bad taste and nausea deadly. As of now, experts recommend talking to your doctor to decide if taking zinc \nlozenges is right for you.^{<a href=\"http://www.mayoclinic.org/diseases-conditions/common-cold/expert-answers/zinc-for-colds/faq-20057769\" rel=\"nofollow noreferrer\">8</a>}</p>\n\n<p><strong>What is the best type of zinc lozenge to take?</strong></p>\n\n<p>Well first, as I said above, there is no conclusive evidence. There is also no definite best type of zinc lozenge to take. Of the studies that showed positive results, zinc gluconate was used the most, but zinc sulfate and zinc acetate were also shown to be effective. Of the trials that showed no noteworthy effect, zinc gluconate was also the most tested type, but zinc acetate also showed no effect. According to <a href=\"http://www.webmd.com/cold-and-flu/cold-guide/zinc-lozenges-cold-remedy#2\" rel=\"nofollow noreferrer\">WebMD</a>, researchers are still trying to figure out which type of zinc lozenge is the best.</p>\n\n<p><strong>Risks of taking zinc supplements</strong></p>\n\n<p>Taking zinc lozenges hasn't been shown to produce any major side-effects. Sometimes, people taking them may experience bad taste in their mouth and possibly nausea. Nasal spray, as you mentioned is also not good. It may even cause loss of smell.</p>\n\n\n\n<hr>\n\n<p>^{[<a href=\"http://ijp.tums.ac.ir/index.php/ijp/article/viewArticle/928\" rel=\"nofollow noreferrer\">1</a>] <a href=\"http://ijp.tums.ac.ir/index.php/ijp/article/viewArticle/928\" rel=\"nofollow noreferrer\">Effects of Zinc Supplementation in Occurrence and Duration of Common Cold in School Aged Children during Cold Season: a Double-Blind Placebo-Controlled Trial</a>}</p>\n\n<p>^{[<a href=\"http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001364.pub4/abstract\" rel=\"nofollow noreferrer\">2</a>] <a href=\"http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001364.pub4/abstract\" rel=\"nofollow noreferrer\">Zinc for the common cold</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/6367635\" rel=\"nofollow noreferrer\">3</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/6367635\" rel=\"nofollow noreferrer\">Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18279051?dopt=Abstract\" rel=\"nofollow noreferrer\">4</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18279051?dopt=Abstract\" rel=\"nofollow noreferrer\">Duration and severity of symptoms and levels of plasma interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor, and adhesion molecules in patients with common cold treated with zinc acetate.</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15496046?dopt=Abstract\" rel=\"nofollow noreferrer\">5</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15496046?dopt=Abstract\" rel=\"nofollow noreferrer\">Efficacy of zinc against common cold viruses: an overview.</a>}</p>\n\n<p>^{[<a href=\"http://aac.asm.org/content/31/8/1183.abstract?ijkey=c54e7d9e7cfc347b5eb4aca02fe68276ebe7863b&amp;keytype2=tf_ipsecsha\" rel=\"nofollow noreferrer\">6</a>] <a href=\"http://aac.asm.org/content/31/8/1183.abstract?ijkey=c54e7d9e7cfc347b5eb4aca02fe68276ebe7863b&amp;keytype2=tf_ipsecsha\" rel=\"nofollow noreferrer\">Two randomized controlled trials of zinc gluconate lozenge therapy of experimentally induced rhinovirus colds.</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11073753?dopt=Abstract\" rel=\"nofollow noreferrer\">7</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11073753?dopt=Abstract\" rel=\"nofollow noreferrer\">Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds.</a>}</p>\n\n<p>^{[<a href=\"http://www.mayoclinic.org/diseases-conditions/common-cold/expert-answers/zinc-for-colds/faq-20057769\" rel=\"nofollow noreferrer\">8</a>] <a href=\"http://www.mayoclinic.org/diseases-conditions/common-cold/expert-answers/zinc-for-colds/faq-20057769\" rel=\"nofollow noreferrer\">Will taking zinc for colds make my colds go away faster?</a>}</p>\n\n<p>^{<a href=\"http://www.webmd.com/cold-and-flu/cold-guide/zinc-lozenges-cold-remedy#2\" rel=\"nofollow noreferrer\">WebMD - Zinc for Colds: Lozenges &amp; Nasal Sprays</a>}</p>\n", "score": 21 }, { "answer_id": 724, "body": "<p>I put a lot of trust in the <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23775705\" rel=\"nofollow\">Cochrane Collaboration's answer</a> for just about any question they answer. @michaelpri cited their answer to this question, and I think it is worth posting as a separate answer:</p>\n\n<blockquote>\n <p>Zinc administered within 24 hours of onset of symptoms reduces the duration of common cold symptoms in healthy people but some caution is needed due to the heterogeneity of the data. As the zinc lozenges formulation has been widely studied and there is a significant reduction in the duration of cold at a dose of ≥ 75 mg/day, for those considering using zinc it would be best to use it at this dose throughout the cold. Regarding prophylactic zinc supplementation, currently no firm recommendation can be made because of insufficient data. When using zinc lozenges (not as syrup or tablets) the likely benefit has to be balanced against side effects, notably a bad taste and nausea.</p>\n</blockquote>\n", "score": 3 } ]

[ "treatment", "common-cold" ]

[ { "answer_id": 5048, "body": "<p>I've written on this subject a few times, but the most <a href=\"https://health.stackexchange.com/questions/4456/in-a-viral-infection-which-symptoms-are-caused-by-the-virus-itself-and-which-s/4528#4528\">relevant question</a> ended up being closed, and the other is on <a href=\"https://biology.stackexchange.com/questions/21507/why-dont-we-develop-immunity-against-common-cold/21802#21802\">Bio.SE</a>, so I will mostly focus on tailoring the information there to the specifics of this question.</p>\n\n<p>If you look at ether of my previous answers, you will note the first thing we need to establish is what is causing the common cold. From the body of evidence coming from the <a href=\"http://www.hindawi.com/journals/jrm/2014/469393/\" rel=\"noreferrer\">US</a> and <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22321179\" rel=\"noreferrer\">China</a> I believe the answer to that is <a href=\"https://en.wikipedia.org/wiki/Rhinovirus\" rel=\"noreferrer\">HRV</a> followed by <a href=\"https://en.wikipedia.org/wiki/Human_respiratory_syncytial_virus\" rel=\"noreferrer\">RSV</a>.</p>\n\n<p>Your immune system is actually <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26557722\" rel=\"noreferrer\">directly attacked</a> by two of the proteins RSV makes when it infects cells (NS1 and NS2). This knowledge is actually linked to a pretty cool <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25249281\" rel=\"noreferrer\">vaccine idea</a> for RSV. Thus I think it quite appropriate to think that active RSV infections weaken your immune system.</p>\n\n<p>Looking at the very good epidemiology data coming from China (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3750056/\" rel=\"noreferrer\">here's another example</a> in addition to the first), it seems that the rate of co-infection, that is something else besides these two viruses infecting the patient, is quite high, particularity with RSV. This would imply that other pathogens take advantaged of a \"weakened\" immune system in an RSV infection.</p>\n\n<p>It's less clear with HRV, but that might just be because of how amazingly common HRV infections are. It <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23806456\" rel=\"noreferrer\">seems</a> as though HRV induces a good <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/24767874\" rel=\"noreferrer\">immune response</a>, in <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26122508\" rel=\"noreferrer\">healthy patients</a>, but it was still commonly found with other pathogens present (though not in rates as high as RSV). There is not a clear mechanism for HRV if it is in fact weakening the immune system (which actually might be better described as a \"distracted\" immune system in this case).</p>\n\n<p>As for what you can do? Not a whole lot once symptoms show up. Contrary to whatever ads you may see, even some <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/10543583\" rel=\"noreferrer\">poor un-blinded trials</a>, taking vitamin C is <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25010554\" rel=\"noreferrer\">not going to help</a> after you <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23440782\" rel=\"noreferrer\">already have the cold</a>. Even the <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/17636648\" rel=\"noreferrer\">prophylactic benefit</a> seems to only be in certain cases, and I want to strongly discourage megadosing vitamin C, which in most cases does nothing helpful (and can <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/7008359\" rel=\"noreferrer\">cause problems</a> of it's own).</p>\n\n<p>Staying hydrated is always a good option, as is washing your hands and coughing/sneezing into your elbow to prevent infecting others. Other than that, you can hope for any of the vaccine candidates currently be researched to actually work, or that one of the small molecule inhibitors (anti-viral drugs) to actually be safe.</p>\n", "score": 5 } ]

[ "immune-system", "common-cold", "infection" ]

[ { "answer_id": 1845, "body": "<p>I think the comment made by Carpetsmoker is important in this context.</p>\n\n<p>Some may find surprising (at least I did) that actually fluoride toothpaste is not clearly superior to fluoride containing mouth rinses according to a <a href=\"http://www.cochrane.org/CD002780/ORAL_one-topical-fluoride-toothpastes-or-mouthrinses-or-gels-or-varnishes-versus-another-for-preventing-dental-caries-in-children-and-adolescents\" rel=\"nofollow noreferrer\">Cochrane Review published in 2009</a>. Unfortunately all reviews are about children or adolescent patients.</p>\n\n<p>Mark Gabriel wonders the intermittent use of mouth rinses. When one is planning of intermittent use it is only natural that mouth rinse is used alongside with regular brushing. Then were faced with the important aspect pointed out by Carpetsmoker. Of course one could use brushing and mouth rinse alternatively since they are equally effective preventing caries. I think one should use either one and not to alternate since usually the more complex routines one developed, more likely they fail.</p>\n\n<p>As so, I think we should look at whether mouth rinses provide any additional benefit to brushing. Three most common active ingredients in mouth rinses are some form of alcohol, chlorhexidine and fluoride (<a href=\"https://en.wikipedia.org/wiki/Mouthwash#Custom_formulations\" rel=\"nofollow noreferrer\">Wikipedia</a>).</p>\n\n<p>The longer-term effects of any treatment should always be evaluated, especially in this case since the use is projected to last possible of life-time. Chlorhexidine containing mouth rinses may cause staining and affect oral flora. The are no specific guidelines how long to use chlorhexidine containing mouth rinses but one sources discourages using it more than 3-4 weeks (<a href=\"http://www.dentalhealth.ie/dentalhealth/teeth/mouthrinses.html\" rel=\"nofollow noreferrer\">1</a>,<a href=\"http://www.australianprescriber.com/magazine/32/6/162/4/\" rel=\"nofollow noreferrer\">3</a>). </p>\n\n<p>There are some health concerns also regarding the alcohol containing mouth rinses. Currently it is controversial whether alcohol containing mouth rinses predispose to cancer (<a href=\"http://www.dentalhealth.ie/dentalhealth/teeth/mouthrinses.html\" rel=\"nofollow noreferrer\">1</a>,<a href=\"https://en.wikipedia.org/wiki/Mouthwash#Alcohol\" rel=\"nofollow noreferrer\">2</a>,<a href=\"http://www.australianprescriber.com/magazine/32/6/162/4/\" rel=\"nofollow noreferrer\">3</a>). In general the possible adverse effects of long-term use are quite poorly established. </p>\n\n<p>There is a <a href=\"http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD002781.pub2/abstract\" rel=\"nofollow noreferrer\">2004 Cochrane review</a> investigating the effects of combining mouth rinse to regular brushing (<a href=\"https://www.google.fi/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=2&amp;cad=rja&amp;uact=8&amp;ved=0CCcQFjABahUKEwjfrLXty57HAhWCDCwKHd43AYA&amp;url=http%3A%2F%2Fwww.update-software.com%2Fpdf%2FCD002781.pdf&amp;ei=S6PIVZ_bGIKZsAHe74SACA&amp;usg=AFQjCNHivA-mxx_FyD5MdZUQ_AEyr-BH6g&amp;sig2=ciQc9dBBFfpbu4TpEYAROg&amp;bvm=bv.99804247,d.bGg\" rel=\"nofollow noreferrer\">Free review</a>).</p>\n\n<p><a href=\"https://i.stack.imgur.com/rL7Oi.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/rL7Oi.jpg\" alt=\"enter image description here\"></a></p>\n\n<p><em>The main outcome was caries increment measured by the change in decayed, missing and filled tooth surfaces (D(M)FS).</em></p>\n\n<p>Five authors investigated brushing+mouth rinse versus brushing. There is some benefit from the combination treatment but it is very minimal. The same conclusion was drawn in two reviews by American Dental Association: \"<em>Based on his findings, the author said that mouthrinses made with CHX, essential oils, or CPC could help reduce plaque and gingivitis in people who brushed and flossed. He also said that using these rinses along with brushing and flossing reduced plaque and gingivitis more than brushing and flossing alone.</em>\" (<a href=\"http://ebd.ada.org/en/evidence/evidence-by-topic/periodontics/clinical-efficacy-of-antimicrobial-mouthrinses?Tab=3\" rel=\"nofollow noreferrer\">4</a>).</p>\n\n<p>After a long commentary I still did not answer the question in the topic. But, to conclude, there <strong>may be</strong> some benefit combining mouth rinse and brushing. Intermittent use may be better if mouth rinse contains alcohol or chlorhexidine. I am fairly certain that current literature does not include explicit answer to the OP´s question.</p>\n", "score": 2 } ]

[ "dentistry" ]

[ { "answer_id": 15065, "body": "<p>In general, the benefit of flu shots is to the general population. Taking the cited value of 40%-60% from the CDC, we can say that it might be a coin toss for you <em>personally</em> to be protected from influenza by the shot. However, if many thousands of people take the flu shot, even if it only works on 40% of them, it helps protect the remaining population from the spread of the virus (AKA herd immunity). This is especially important to those within the population who cannot access the shot or cannot receive it due to a preexisting medical condition. As Graham Chiu's answer points out, influenza is no joke, especially for vulnerable members of the population (such as the elderly or people with certain medical conditions).</p>\n\n<p>With regards to mercury in the flu shot, the specific additive is called \"Thimerosal\". Firstly: <a href=\"https://www.cdc.gov/flu/protect/vaccine/thimerosal.htm\" rel=\"noreferrer\">not all flu shots contain Thimerosal</a>. If you feel strongly about it, ask your pharmacist for a vaccine that doesn't contain Thimerosal. The additive is a <a href=\"https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html\" rel=\"noreferrer\">preservative</a> to prevent bacteria or fungi from growing in multi-dose vials containing the influenza vaccine. For explanations as to why you don't need to worry about Thimerosal, see the <a href=\"https://health.stackexchange.com/a/15070/12655\">other</a> great <a href=\"https://health.stackexchange.com/a/15074/12655\">answers</a> below.</p>\n\n<p>Some further information to put your mind at ease. In their <a href=\"https://www.scientificamerican.com/article/straight-talk-about-vaccination/\" rel=\"noreferrer\">article</a> in Scientific American, Matthew F. Daly and Jason M. Glanz (a pediatrician and epidemiologist respectively at Kaiser Permanente's Institute for Health Research in Denver) have this to say about the safety of vaccines:</p>\n\n<blockquote>\n <p>Because vaccines are given to huge numbers of people, including healthy infants, they are held to a much higher safety standard than medications used for people who are already sick.</p>\n</blockquote>\n\n<p>From the same article:</p>\n\n<blockquote>\n <p>The key facts [you] need to know, though, are that vaccines prevent potentially fatal diseases, that vaccines have a high degree of safety, and that their safety is constantly evaluated and reevaluated in a system operating independently from the pharmaceutical companies that make vaccines.</p>\n</blockquote>\n\n<p>As a final note: in that article shared by the OP there are several scientifically unsound arguments and factual errors. I'm not going through the effort of refuting them all here. It is however worth pointing out that the presence of Thimerosal in vaccines is not a secret, and is well known among the scientific and medical community. In a <strong>brief</strong> search of medical literature in the medical science database <em><a href=\"https://www.ncbi.nlm.nih.gov/\" rel=\"noreferrer\">PubMed.gov</a></em> (free to the public, by the way) with the search terms \"influenza vaccine safety\" I could find no results making any claims about adverse side effects due to Thimerosal. In a database containing literally millions of independent, peer-reviewed medical scientific publications, you will be hard pressed to find any supporting the claims made in the aforementioned article shared by the OP.</p>\n\n<p>In fact, this <a href=\"http://dx.doi.org/10.1080/21645515.2017.1423153\" rel=\"noreferrer\">review article</a> (where researchers summarize the results of 190 other sources on vaccine safety) had this to say on the topic of vaccine safety [paraphrased by me]:</p>\n\n<blockquote>\n <ul>\n <li>Influenza causes substantial death, suffering and socioeconomic impact worldwide.</li>\n <li>Vaccination is the best defense against influenza.</li>\n <li>Influenza vaccines are \"very safe\".</li>\n <li>The only known side effects of influenza vaccines are temporary nasal congestion (runny nose) and sometimes allergic reactions.</li>\n <li>Allergic reactions appear in less than 1 out of every 1,000,000 doses.</li>\n <li>Children with asthma under the age of 2 are particularly susceptible to the side effects of the influenza vaccine and more study is required to ensure it's safety for this particular high-risk group.</li>\n </ul>\n</blockquote>\n\n<p>In other words, infants who have problems breathing might be more significantly affected by allergic reactions or congestion. That's all they have to say about flu vaccine side effects (regardless of whether they contain Thimerosal). Finally, a direct quote from the conclusion:</p>\n\n<blockquote>\n <p>Vaccines have to meet higher safety standards, since they are administered to healthy people, mainly healthy children. The monitoring of annual influenza vaccine safety, which is particular [sic] important on account of the annual changes in the viral antigen composition of the vaccine, constitutes a critical component of the influenza vaccination program. Indeed, not only does this strategy ensure the safety of vaccines, it can also maintain public trust in the national vaccination program.</p>\n</blockquote>\n", "score": 61 }, { "answer_id": 15070, "body": "<p>Tackling your points in turn, in inverted order:</p>\n\n<blockquote>\n <p>flu is an irritant but nowhere near deadly</p>\n</blockquote>\n\n<p>You are probably confusing the flu (influenza) with the common cold, <a href=\"https://www.cdc.gov/flu/about/qa/coldflu.htm\" rel=\"noreferrer\">which is colloquially often called “the flu”</a>, or <a href=\"https://en.wikipedia.org/wiki/Gastroenteritis\" rel=\"noreferrer\">gastroenteritis</a> (colloquially called “stomach flu”). Unfortunately these are actually very different diseases. The common cold is indeed largely harmless. By contrast, influenza (and potentially also gastroenteritis) is a serious, and potentially deadly, disease. Its symptoms vary but <a href=\"https://www.nhs.uk/conditions/flu/\" rel=\"noreferrer\">it usually leads to high fever, strong pain, diarrhoea and difficulty sleeping</a>. In a word, you’ll feel rotten for the better part of a week.</p>\n\n<p>In addition, the mortality may not <em>seem</em> very high but (even ignoring that it caused the <a href=\"https://en.wikipedia.org/wiki/1918_flu_pandemic\" rel=\"noreferrer\">deadliest epidemic</a> in human history) <a href=\"https://www.cdc.gov/nchs/fastats/flu.htm\" rel=\"noreferrer\"><strong>each year thousands of people die from it in the US alone</strong></a>. In fact, the numbers vary greatly with each season, from about 3,000 to almost 50,000.</p>\n\n<p>As a healthy 40-year-old you are less likely to <em>die</em> from the flu but you could still get very seriously ill. Furthermore, by getting vaccinated, you contribute to <a href=\"https://en.wikipedia.org/wiki/Herd_immunity\" rel=\"noreferrer\">herd immunity</a>. This prevents the flu’s spread and protects other, less healthy people, from dying from the flu.</p>\n\n<blockquote>\n <p>[40%–60% risk reduction] is not considered highly effective for a vaccine.</p>\n</blockquote>\n\n<p>Even a 40% risk reduction is very effective. It’s maybe not considered “highly effective” <em>compared to other vaccines</em> because vaccines, in general, are extremely effective. But compared to other remedies, vaccines are one of the most effective treatment methods.</p>\n\n<p>Rather than thinking of 40%–60% as a coin toss, think of it this way: amongst the vaccinated population, the <a href=\"https://en.wikipedia.org/wiki/Incidence_%28epidemiology%29\" rel=\"noreferrer\">incidence</a> is more than halved (due to the compounding effect of reduced risk of infection in the population). This is impressive.</p>\n\n<blockquote>\n <p>[The flu vaccine contains] mercury that is harmful to the body, according to Natural News.</p>\n</blockquote>\n\n<p>This is intentionally deceptive: <a href=\"https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index.html\" rel=\"noreferrer\">flu vaccines do not contain elementary mercury</a> (and never have)! <em>Some</em> flu vaccines contain <a href=\"https://en.wikipedia.org/wiki/Thiomersal\" rel=\"noreferrer\">thiomersal</a> (or “thimerosal”), which in turn contains <em>ethylmercury</em>. Despite its name, this is a different compound, and does not have the same chemical properties as elementary mercury.¹ Contrary to what <em>Natural News</em> claims, thiomersal in vaccines is safe: it has never been found to produce a negative effect in humans.²</p>\n\n<p>Beware of your news sources: <a href=\"https://en.wikipedia.org/wiki/Natural_News\" rel=\"noreferrer\"><em>Natural News</em> is a scam website</a> that lies to sell ineffective, unregulated, and potentially harmful supplements. When researching health topics, always cross-reference your information with respectable sources such as the WHO, the NHS or the CDC. You don’t need to <em>exclusively</em> rely on them but they accurately portray the scientific consensus and, unlike sites like <em>Natural News</em>, they have no financial interest in lying to the public, since they do not make profit off it. Furthermore, they are funded independently by different governments.</p>\n\n<hr>\n\n<p>_{¹ This is a very important point, so it bears explaining: Consider table salt. Table salt is the chemical compound sodium chloride. Both sodium and chloride, in isolation, are highly toxic. But when combined chemically, as in table salt, they form a harmless compound that is safe for normal consumption. The same is true for the relationship between mercury and ethylmercury.}</p>\n\n<p>_{² As everywhere, <em>the dose makes the poison</em>. Thiomersal in high concentrations is toxic, just like table salt. Toxicity is often measured in <a href=\"https://en.wikipedia.org/wiki/Median_lethal_dose\" rel=\"noreferrer\">LD₅₀</a>. Salt has an LD₅₀ of <a href=\"http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf\" rel=\"noreferrer\">12357 mg/kg</a> in humans, which means that <a href=\"http://www.traditionaloven.com/culinary-arts/cooking/table-salt/convert-kilogram-kg-to-table-spoon-tbsp.html\" rel=\"noreferrer\">approx. 58 tablespoons</a> are problematic for an 80 kg man. Thiomersal has an LD₅₀ of <a href=\"https://en.wikipedia.org/wiki/Thiomersal\" rel=\"noreferrer\">75 mg/kg</a> (in rats), which means that you’d need to vaccinate that 80 kg man <a href=\"https://www.cdc.gov/mmwr/volumes/66/rr/rr6602a1.htm\" rel=\"noreferrer\">over 100,000 times</a>, at once, for a similar effect!}</p>\n", "score": 41 }, { "answer_id": 15062, "body": "<p>Influenza deaths are not specifically tracked in those over the age of 18 but they can be estimated from death certificates.</p>\n\n<blockquote>\n <p>CDC estimates that from 2010-2011 to 2013-2014, influenza-associated deaths in the United States ranged from a low of 12,000 (during 2011-2012) to a high of 56,000 (during 2012-2013). Death certificate data and weekly influenza virus surveillance information was used to estimate how many flu-related deaths occurred among people whose underlying cause of death on their death certificate included respiratory or circulatory causes.</p>\n</blockquote>\n\n<p>So deaths from influenza are often from a secondary bacterial pneumonia or excessive immune response (cytokine storm) to the flu infection. Some young people can die <a href=\"https://www.nbcnews.com/health/health-news/here-s-how-flu-virus-kills-some-people-so-quickly-n839936\" rel=\"noreferrer\">within hours</a> of the flu infection from the latter reason. </p>\n\n<p>And if we just look at <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5359836/table/Tab3/\" rel=\"noreferrer\">hospitalization rates</a> we can see that for the age range 18-49, the rate of 41/100,000 is under half that of the average but twice higher than age range 5-17 years. </p>\n\n<p>And 50 million deaths from the 1918 pandemic makes your statement that \"flu is an irritant\" completely erroneous.</p>\n\n<p>Interestingly a <a href=\"http://www.thelancet.com/pdfs/journals/lanpub/PIIS2468-2667(17)30004-X.pdf\" rel=\"noreferrer\">new paradigm</a> for managing seasonal flu has been suggested. The issue is that the people who most need the vaccination (elderly, sick, very young) are those that benefit the least from vaccination due to an impaired immune response to the vaccine, and it may be more effective to vaccinate the older young who respond well to vaccination:</p>\n\n<blockquote>\n <p>Furthermore, influenza\n epidemiology is unfortunately characterised by\n dissociation between populations most likely to\n have severe disease (infants and elderly people), and\n populations most likely to benefit from vaccination\n (older children and adolescents—ie, those aged\n 2–16 years).3\n Older children and adolescents seem to\n be important for the early propagation of influenza\n in populations, and the efficacy of influenza vaccines\n is greater in these populations than in elderly people,\n but they are generally not prioritised for immunisation\n because of their lower risk of morbidity and mortality\n from this infection.3\n This paradoxical state of affairs\n has led some researchers to suggest that the best way\n to minimise the burden of seasonal influenza would\n be to focus immunisation programmes on children,\n adolescents, and young adults, with benefit accrued by\n elderly people and infants as a result of herd immunity.3</p>\n</blockquote>\n\n<p>And ...</p>\n\n<blockquote>\n <p>analysis highlights\n the importance of herd effects for decision makers:\n a rapidly implemented LAIV programme focused on\n children aged 2–16 years is actually more effective\n at preventing disease in elderly people than a more\n slowly implemented programme that includes both\n LAIV and direct immunisation of elderly people\n themselves. This finding is because a rapid, early focus\n on young individuals, in whom the vaccine is more\n effective, stops the influenza epidemic in its tracks. </p>\n</blockquote>\n", "score": 17 }, { "answer_id": 15082, "body": "<blockquote>\n <p>Influenza vaccines do not have satisfactory effective rates of preventing flu. Flu vaccination reduces the risk of flu illness by between 40% and 60%</p>\n</blockquote>\n\n<p>Vaccines aren't meant to stop diseases by making 100% invulnerable individuals. Of course we want the highest possible efficacy, but the primary benefit is the large impact they have on a collective level, by limiting the spread of a disease, so that it snuffs itself off.</p>\n\n<p>It's all about reducing the <a href=\"https://en.wikipedia.org/wiki/Basic_reproduction_number\" rel=\"noreferrer\">basic reproduction number (<em>R</em>₀)</a>, the number of cases of the disease that are caused by infection from one case of the desease. There are 3 ranges this number can fall into</p>\n\n<ul>\n<li>1 &lt; <em>R</em>₀ Each person, on average, infects more than 1 person before recovering. Disease spreads as more people get infected than people are recovering.</li>\n<li><em>R</em>₀ = 1 Each person, on average, infects exactly 1 other person before recovering. The disease spread plateaus (i.e. the number of infected remains the same.), as the number of people getting infected exactly matches the number of people recovering.</li>\n<li>0 ≤ <em>R</em>₀ &lt; 1 Each person, on average, infects less than 1 person before recovering. The disease gets snuffed out over time, as people recover faster than people are getting infected.</li>\n</ul>\n\n<p>The exponential math that models disease spread applies in many areas, such as in nuclear chain reactions, where the <a href=\"https://en.wikipedia.org/wiki/Nuclear_chain_reaction#Effective_neutron_multiplication_factor\" rel=\"noreferrer\">effective neutron multiplication factor</a> is the average number of neutrons from one fission that cause another fission. Just as <a href=\"https://en.wikipedia.org/wiki/Control_rod\" rel=\"noreferrer\">control rods</a> are used in nuclear reactors to maintain the <em>k</em> around 1 (a stable, non-growning, non-dying rate of reaction), vaccines can be used to bring <em>R</em>₀ below 1, so that deceases snuff themselves out.</p>\n\n<p>Herd immunity is a proportional to the product of vaccine efficacy, and the vaccination rate. Here's a simplified visualization of herd immunity, which I think presumes 100% vaccine efficacy. We can compensate for lower vaccine efficacy by increasing the vaccination rate.</p>\n\n<p><a href=\"https://i.imgur.com/J7LANQ4.gif\" rel=\"noreferrer\"><img src=\"https://i.imgur.com/J7LANQ4.gif\" alt=\"Herd immunity simulation\"></a></p>\n\n<p>Not using a vaccine because it's \"only\" 40% - 60% effective is counterproductive: that's <strong><em>exactly</em></strong> when we need a high vaccination rate, <strong><em>the most!</em></strong></p>\n", "score": 14 }, { "answer_id": 15074, "body": "<p>Other answers have explained why being vaccinated is generally a good idea, and I fully support the ones that do. That said, the article you've linked to does indeed present some very scary points, and I fully understand why reading something like that would give you some doubts about your own safety, so I'd like to directly tackle the key point raised by it.</p>\n\n<p>I have no medical qualifications whatsoever, so just like you I'm reading the information that's available as a lay person.</p>\n\n<blockquote>\n <p>Mercury is toxic at any dose when injected into the body, even in micrograms.</p>\n</blockquote>\n\n<p>Injecting a syringe full of mercury into your body is definitely a <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2740532/\" rel=\"noreferrer\">bad idea</a>. The article is mostly worried about Thimerosal, which is used as a preservative. The US National Toxicology Department has tested this ingredient in response to fears, and you can see the results <a href=\"https://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/thimerosal_508.pdf\" rel=\"noreferrer\">here</a>. It tells us the following:</p>\n\n<blockquote>\n <p>In this study, the LD50 of thimerosal in rats was 98 mg/kg</p>\n</blockquote>\n\n<p>The LD50 being 98mg/kg means that, to have a 50% chance of killing a rat that weighs one kilogram, you'll need to inject 98mg of Thimerosal. Looking at <a href=\"http://web.jhu.edu/animalcare/procedures/rat.html\" rel=\"noreferrer\">this</a>, 400g for a rat's weight seems like a reasonable estimate, so it'll take about 40mg of Thimerosal to have a 50% chance of killing a pet rat. Heading back to your article:</p>\n\n<blockquote>\n <p>As you can see from this snapshot, the package insert readily admits that each vaccine dose “contains 50 mcg thimerosal (&lt;25 mcg mercury).”</p>\n</blockquote>\n\n<p>Yep, it absolutely does. Converting the units, 50mcg=0.05mg. If we want to kill that rat from Thimerosal poisoning, we'd need to inject it with 800 of these flu shots. I'm going to re-state this in big text just in case you're only skimming:</p>\n\n<p><strong>To stand a decent chance of killing a pet rat from mercury poisoning, you'd need to inject it with 800 of the flu vaccines discussed in that article, all at the same time</strong></p>\n\n<p>You're probably a lot bigger than your average lab rat, so we're talking tens of thousands of flu shots before the mercury inside it starts getting dangerous.</p>\n\n<p>The article also discusses formaldehyde, and if you're interested you can do your own research into the toxicity of that and see how many flu shots you'd need to be in danger of death from formaldahyde poisoning.</p>\n\n<p>It's a real shame that the articles trying to tell you vaccines are dangerous are so exciting to read, whilst articles describing actual scientific research are so dry and boring. You can see why ideas like this gain so much traction - it's terribly exciting to read! Unfortunately, it just doesn't stand up to any serious scrutiny.</p>\n", "score": 12 }, { "answer_id": 15127, "body": "<p>A few more points, in addition to the good answers you already have and just addressing:</p>\n\n<blockquote>\n <p>Does it make sense for a healthy male in his early 40s to take the influenza vaccine [...]?</p>\n</blockquote>\n\n<p><strong>Short answer</strong>: healthy 40-year-old male already excludes a number of high risk/priority groups, but not all of them (e.g. if you help taking care of 90- year-old grandma, maybe you don't want to risk <em>her</em> health). </p>\n\n<hr>\n\n<p><strong>long answer</strong></p>\n\n<ul>\n<li><p>Several answers above have already discussed the topic of herd immunity. The difficulty here with the flu is that it changes so rapidly that we cannot really get there (which is also the reason for the low efficacy of the flu shot and the need to develop and distribute new shots every flu season).</p></li>\n<li><p>In general, whether it makes sense to try approaching herd immunity, i.e. to recommend vaccination for everyone also depends on circumstances. </p>\n\n<ul>\n<li>E.g. in Germany we have no yellow fever, so vaccination is only recommended for people travelling to regions that have. </li>\n</ul></li>\n<li><p>Now for the flu, at least with current vaccine development technology, we cannot reach true herd immunity (it changes too fast). However, if we can reduce the number of infections by half, and slow down the spread of the infection, that can make a vital difference for the health system: there are only so many patients that can be taken care of at a given time. If you can keep the number of patients below what the capabilities are, that's much better for everyone compared to situations where patients can only be put to beds in the hallway of the hospital and half of the staff is ill as well.<br>\nFrom a macroscopic perspective, you can then ask what strategy is better: e.g. vaccination campaign or building more hospitals. </p></li>\n<li><p>There's also an intermediate concept between full herd immunity and no vaccination: vaccinate only certain groups of people. These will typically be </p>\n\n<ul>\n<li>persons more susceptible to the disesase (likely to contract and/or higher risk of (severe) complications)</li>\n<li>persons that may be in the position to infect many other and/or many susceptible people (for the flu: public office, teachers, health care workers)</li>\n<li>health care workers: you need them particularly when there's an outbreak of disease </li>\n</ul>\n\n<p>For the <strong>flu</strong>, these <strong>high risk/priority groups</strong> are:</p>\n\n<ul>\n<li>Kids 6 months - 4 years (CDC)</li>\n<li>People over 50 (CDC) or 60 (RKI)</li>\n<li>People with certain chronic diseases (CDC and RKI)</li>\n<li>Residents of retirement or nursing homes in general (CDC and RKI) </li>\n<li>Pregnant women (CDC and RKI) </li>\n<li>Caretakers and household contacts for high risk persons (CDC and RKI)</li>\n<li>Persons with increased professional risk (health care workers, CDC and RKI), workers in public offices, teachers etc. (RKI)</li>\n<li>Persons working with birds (this is in order to avoid double infection with human and avian influenza, RKI)</li>\n<li>American Indians/Alaska Natives (CDC)\n(Lists from the documents linked below)</li>\n</ul></li>\n<li><p><a href=\"https://www.cdc.gov/flu/protect/whoshouldvax.htm\" rel=\"nofollow noreferrer\">CDC decided that it is worth trying to get as many people vaccinated against flu as possible</a>, whereas the <a href=\"https://www.rki.de/EN/Content/infections/Vaccination/recommandations/34_2017_engl.pdf?__blob=publicationFile\" rel=\"nofollow noreferrer\">RKI [German equivalent of CDC] has a certain groups policy</a><br>\nNote that this does not necessary mean a controversy between experts, but this may be caused by regional differences.</p></li>\n<li><p>Just to be complete: there are also counter-indications, but \"healthy\" pretty much excludes them.</p>\n\n<p>-</p></li>\n</ul>\n", "score": 4 } ]

[ "vaccination", "influenza", "mercury" ]

[ { "answer_id": 77, "body": "<h3>Introduction</h3>\n<p>There have been numerous studies on this topic, and there are a number of artificial sweeteners, so the following is a discussion of three of the most important, saccharin, cyclamate and aspartame, as well as three more which are currently approved for use in food by the FDA, acesulfame potassium, sucralose, and neotame, in less detail.</p>\n<h3>Saccharin</h3>\n<p>There have been over 50 studies discussing saccharin, specifically its effects on rats, especially regarding cancer. About 20 of these involved rats consuming saccharin for over 1.5 years, nineteen of which found no significant differences between rats fed saccharin and rats not fed saccharin.<a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full\" rel=\"noreferrer\">¹</a> The cancer-positive study did find a link between saccharin and bladder cancer, but used a type of rat susceptible to bladder cancer.<a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full#ref-5\" rel=\"noreferrer\">²</a> <a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full#ref-6\" rel=\"noreferrer\">³</a></p>\n<p>There have also been multi-generational studies in which saccharin was fed to rats and their offspring, and found that male, second-generation rats fed saccharin were more at risk for bladder cancer than male, second-generation rats not fed saccharin.<a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full#ref-7\" rel=\"noreferrer\">⁴</a> <a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full#ref-8\" rel=\"noreferrer\">⁵</a> However, the same link could not be found in humans, as studies have found that cancer in rats is not a good predictor of cancer in humans. For example, low doses of Vitamin C cause cancer in rats.<a href=\"http://webcache.googleusercontent.com/search?q=cache:PTYDMGWHhfwJ:foodbiology.org/index.php/foodbio/article/download/16465/8560%20&amp;cd=2&amp;hl=en&amp;ct=clnk&amp;gl=us\" rel=\"noreferrer\">⁶</a> With no conclusive evidence linking saccharin to human health risk, bans on saccharin were lifted, at least in the United States.<a href=\"http://www.fda.gov/AboutFDA/WhatWeDo/History/ThisWeek/ucm117714.htmhttp://www.fda.gov/AboutFDA/WhatWeDo/History/ThisWeek/ucm117714.htm\" rel=\"noreferrer\">⁷</a></p>\n<h3>Cyclamate</h3>\n<p>After being approved by the FDA for use in food in 1951, cyclamate became a common artificial sweetener in American households. After a study in 1969 found links between cyclamate and bladder cancer in rats,<a href=\"http://www.sciencemag.org/content/168/3939/1605.1.full.pdf?ijkey=16a7af61bde2e72ab732c0609872f62949fa6051&amp;keytype2=tf_ipsecsha\" rel=\"noreferrer\">⁸</a> the FDA banned cyclamate in food.</p>\n<p>Later, a long-term study was conducted in which monkeys were fed cyclamate every day for 24 years. One group was fed cyclamate at dosages equivalent to 6 cans of diet soda a day, another at dosages equivalent to 30 cans of diet soda a day. The study concluded that there is no significant link between cyclamate and cancer in monkeys.<a href=\"http://toxsci.oxfordjournals.org/content/53/1/33.full.pdf\" rel=\"noreferrer\">⁹</a> While a petition has been filed with the FDA for the lifting of the cyclamate ban, however, the petition is not being actively considered for reasons unrelated to cancer.<a href=\"http://www.cancer.gov/cancertopics/causes-prevention/risk/diet/artificial-sweeteners-fact-sheet\" rel=\"noreferrer\">¹⁰</a></p>\n<h3>Aspartame</h3>\n<p>Approved for use in food by the FDA in 1981, a 1996 study posited a possible link between a general increase in brain tumor incidence and aspartame.<a href=\"http://www.whilesciencesleeps.com/pdf/329.pdf\" rel=\"noreferrer\">¹¹</a> A multitude of studies followed, among the largest of which found no link between aspartame consumption and brain tumors,<a href=\"http://cebp.aacrjournals.org/content/15/9/1654.full.pdf\" rel=\"noreferrer\">¹²</a> and no link between aspartame consumption and changes in brain function.<a href=\"http://ajcn.nutrition.org/content/68/3/531.full.pdf\" rel=\"noreferrer\">¹³</a></p>\n<p>At one point, an editorial intended to directly address the 1996 study revealed that the conclusion was largely the result of ecological fallacy, essentially blind assumption.<a href=\"http://annonc.oxfordjournals.org/content/15/10/1460.full\" rel=\"noreferrer\">¹⁴</a> Of course, this is a small sample of the large numbers of studies conducted, including a human study that found little evidence that aspartame is likely to act as a human brain carcinogen.<a href=\"http://jnci.oxfordjournals.org/content/89/14/1072.full.pdf\" rel=\"noreferrer\">¹⁵</a></p>\n<p>Eventually, the FDA released a statement citing a press release by the European Food Safety Authority. The statement, in addition to declaring its intent to better study aspartame, stated that the FDA has not been presented with scientific information that would support a change in its conclusions about the safety of aspartame.<a href=\"http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108650.htm\" rel=\"noreferrer\">¹⁶</a></p>\n<h3>Acesulfame potassium, Sucralose and Neotame</h3>\n<p>Acesulfame potassium was approved by the FDA for use in food in 1988. Sucralose was approved by the FDA for use in food in 1998. Neotame was approved by the FDA for use in food in 2002.</p>\n<p>The FDA states that it reviewed more than 100 safety studies before approving these sweeteners, and that the results of these studies showed no evidence that these sweeteners cause cancer or pose any other threat to human health.<a href=\"http://www.cancer.gov/cancertopics/causes-prevention/risk/diet/artificial-sweeteners-fact-sheet\" rel=\"noreferrer\">¹⁷</a></p>\n<h3>In Short</h3>\n<p>There have been a number of studies reviewing the safety of common artificial sweeteners, with mixed results. However, the quorum conclusion appears to be that even in very high doses, these substances are safe for human consumption. Note, however, that a number of artificial sweeteners were not discussed above, some of which may pose health risks.</p>\n", "score": 21 } ]

[ "nutrition" ]

[ { "answer_id": 311, "body": "<p>There are many factors in determining how much coffee one can drink in a day. Caffeine metabolism¹ is a big one. People who metabolize caffeine slow, probably shouldn't have more than 100mg of caffeine (about a cup) a day. Fast metabolizers of caffeine can usually have between 400-500mg (about 5 cups) a day.² For the general population, 400mg (about 4 cups) should be the limit. Going over this may cause several side effects such as insomnia, restlessness, headaches, and upset stomach.³ It usually isn't very hard to know your limit of drinking coffee. If coffee has a strong effect on you right away, drink less coffee, or consider drinking tea. If coffee has a weak effect on you, then you can drink more. Most people will fall somewhere in between.</p>\n\n<hr>\n\n<p>^{[1] <a href=\"https://health.stackexchange.com/questions/65/why-do-i-feel-shaky-after-only-a-small-amount-of-caffeine/76#76\">Why do I feel shaky after only a small amount of caffeine?</a>}</p>\n\n<p>^{[2] <a href=\"http://www.gbhealthwatch.com/Trait-Caffeine-Consumption.php\" rel=\"noreferrer\">Caffeine Consumption</a>}</p>\n\n<p>^{[3] <a href=\"http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678?pg=1\" rel=\"noreferrer\">Caffeine: How much is too much?</a>}</p>\n", "score": 18 }, { "answer_id": 320, "body": "<p>It really depends on the coffee which its caffeine content (its main psychoactive substance) can vary by size, bean origin, roast method and other factors.</p>\n<p>Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That's roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two &quot;energy shot&quot; drinks. Although caffeine use may be safe for adults, it's not a good idea for children. See: Caffeine: <a href=\"http://www.mayoclinic.org/healthy-living/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678\" rel=\"nofollow noreferrer\">How much is too much? at Mayo Clinic</a></p>\n<p>Higher consumption of 1000–1500 mg per day is associated with a condition known as caffeinism.</p>\n<hr />\n<p>Caffeinated beverages like coffee and soft drinks give short bursts of energy, but can actually cause fluid loss. Caffeine has been shown to temporarily raise blood pressure, and reduces blood flow to inactive limbs.</p>\n<p>Like many drugs, caffeine is <a href=\"http://www.nytimes.com/1994/10/05/us/yes-people-are-right-caffeine-is-addictive.html\" rel=\"nofollow noreferrer\">chemically addictive</a> and recent publication of Diagnostic and Statistical Manual of Mental Disorders (DSM), caffeine withdrawal was finally included as a mental disorder for the first time.</p>\n<p>Soon after you drink coffee (containing caffeine), it’s absorbed through the small intestine and dissolved into the bloodstream and it’s able to penetrate the blood-brain barrier and enter the brain.</p>\n<p>Regular ingestion of the drug (i.e. coffee/tea, soda or energy drinks) alters your brain’s chemistry and physical characteristics actually change over time, leading to fatigue, headaches and nausea if you try to quit. However, compared to many drug addictions, the effects are relatively short-term.</p>\n<p>Few quotes from <a href=\"http://www.dailymail.co.uk/health/article-2792690/sales-sugar-caffeine-laden-energy-drinks-restricted.html\" rel=\"nofollow noreferrer\">Daily Mail</a>:</p>\n<blockquote>\n<p>Large amounts of <strong>caffeine can cause heart palpitations, fits and even death</strong>, as well as raising the risk of Type 2 diabetes.</p>\n<p>Heavy consumption has also been linked to <strong>a greater risk of depression, addiction and alcohol dependency</strong>.</p>\n<p>Energy drinks could be more likely to cause a caffeine overdose because they can be drunk quickly, unlike hot drinks like tea or coffee, the Energy Drink Consumption in Europe study said.</p>\n<p>Several deaths worldwide have been linked to excessive consumption of energy drinks, although scientists say more research is needed to prove a link.</p>\n<p>Recommended maximum caffeine intake is about 400mg per day – equivalent to around five cups of filter coffee.</p>\n</blockquote>\n<p>'Reproductive-aged women (⩽ 300 mg caffeine per day) and children are ‘at risk’ subgroups who may require specific advice on moderating their caffeine intake', <a href=\"http://www.informaworld.com/smpp/content%7Edb=all%7Econtent=a713811152?waited=0\" rel=\"nofollow noreferrer\">study</a> said.</p>\n<p>On <a href=\"http://www.livescience.com/34765-coffee-drinking-is-mental-disorder-dsm.html\" rel=\"nofollow noreferrer\">Live Science</a> we can read:</p>\n<blockquote>\n<p>Coffee drinking could lead to a mental disorder. If you experience\nfive or more symptoms, such as red face, nervousness and restlessness,\nduring or right after your cup of Joe, you may be diagnosed with\ncoffee intoxication.</p>\n</blockquote>\n<p>According to a new edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5), excessive caffeine intake can lead to a condition known as “caffeine intoxication,”.</p>\n<p>In other words, <strong>caffeine withdrawal is now a recognized disorder, and is listed in the <a href=\"http://www.dsm5.org/\" rel=\"nofollow noreferrer\">DSM-5</a>.</strong></p>\n<blockquote>\n<p>“<strong>Caffeine is a drug, a mild stimulant</strong>, which is used by almost\neverybody on a daily basis,” said Dr. Charles O’Brien, who chairs the\nSubstance-Related Disorder Work Group for DSM-5 (via New York Post).\n“But it does have a letdown afterwards. If you drink a lot of coffee,\nat least two or three [236 ml] cups at a time, there will be a rebound\nor withdrawal effect.”</p>\n</blockquote>\n<p>Here are <a href=\"http://www.caffeineinformer.com/caffeine-withdrawal-symptoms-top-ten\" rel=\"nofollow noreferrer\">top 10 caffeine withdrawal symptoms</a>:</p>\n<ol>\n<li>Headache</li>\n<li>Sleepiness</li>\n<li>Irritability</li>\n<li>Lethargy</li>\n<li>Constipation</li>\n<li>Depression</li>\n<li>Muscle Pain/Stiffness</li>\n<li>Lack of Concentration</li>\n<li>Flu-like symptoms</li>\n<li>Insomnia</li>\n</ol>\n<p><strong>In rare cases when consumed at high enough doses, caffeine can kill.</strong></p>\n<p><img src=\"https://i.stack.imgur.com/hPa5n.jpg\" alt=\"caffeine curve\" /></p>\n<hr />\n<p>Related:</p>\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Health_effects_of_caffeine\" rel=\"nofollow noreferrer\">Health effects of caffeine</a> at Wikipedia</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Effect_of_caffeine_on_memory\" rel=\"nofollow noreferrer\">Effect of caffeine on memory</a> at Wikipedia</li>\n<li>(article) <a href=\"http://www.dailymail.co.uk/health/article-2792690/sales-sugar-caffeine-laden-energy-drinks-restricted.html\" rel=\"nofollow noreferrer\">Sales of sugar and caffeine laden energy drinks should be restricted as they 'pose a danger' to children</a> at Daily Mail</li>\n<li><a href=\"https://coffee.stackexchange.com/questions/479/whats-the-minimum-recommended-age-for-drinking-a-coffee\">What's the minimum recommended age for drinking a coffee?</a></li>\n<li><a href=\"http://www.smithsonianmag.com/science-nature/this-is-how-your-brain-becomes-addicted-to-caffeine-26861037\" rel=\"nofollow noreferrer\">This Is How Your Brain Becomes Addicted to Caffeine</a> at Smithsonian</li>\n<li><a href=\"http://lifehacker.com/5585217/what-caffeine-actually-does-to-your-brain\" rel=\"nofollow noreferrer\">What Caffeine Actually Does to Your Brain</a> at Life Hacker</li>\n<li>(study) <a href=\"http://www.informaworld.com/smpp/content%7Edb=all%7Econtent=a713811152?waited=0\" rel=\"nofollow noreferrer\">Effects of Caffeine on Human Health</a>, P. Nawrot, S. Jordan, J. Eastwood, J. Rotstein, A. Hugenholtz and M. Feeley, Food Additives and Contaminants, 2003, Vol. 20, No. 1, pg. 1-30.</li>\n<li>(study) <a href=\"http://pharmrev.aspetjournals.org/content/51/1/83.long\" rel=\"nofollow noreferrer\">Actions of Caffeine in the Brain with Special Reference to Factors That Contribute to Its Widespread Use</a></li>\n<li><a href=\"http://newsfeed.time.com/2013/05/31/caffeine-withdrawal-is-now-a-mental-disorder/\" rel=\"nofollow noreferrer\">Caffeine Withdrawal Is Now a Mental Disorder</a> at Time</li>\n<li>(book) Buzz: The Science and Lore of Alcohol and Caffeine by Stephen Braun</li>\n</ul>\n", "score": 7 }, { "answer_id": 319, "body": "<p>While this is not a complete answer, I'm pointing out here that <a href=\"http://en.wikipedia.org/wiki/Coffee#Health_and_pharmacology\" rel=\"nofollow noreferrer\">coffee intake is adverse to iron absorption</a>. Caffeine does play a role here, although I don't know to what extent other substances in coffee do. I have asked a <a href=\"https://health.stackexchange.com/questions/318/does-decaffeinated-coffee-inhibit-iron-intake-as-well\">separate question here</a>.</p>\n\n<p>For this reason, it is recommended not to drink coffee together with, or directly after iron-rich meals (say, a breakfast with oatmeal and fruits) since the intake and the benefits of the iron would be inhibited. This applies especially to people who have low haemoglobin levels, but also to healthy adults who want to keep their iron levels up. Pregnant women should be especially careful and best avoid coffee completely since <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3414579\" rel=\"nofollow noreferrer\">coffee consumption is linked to iron deficiency anemia in their infants</a>.</p>\n", "score": 5 } ]

[ "nutrition" ]

[ { "answer_id": 562, "body": "<p>Although the <a href=\"https://health.stackexchange.com/a/510/165\">other answer</a> provided some general tips about sleep hygiene and noted that melatonin might be helpful, your question actually touches on an aspect of circadian biology that has been very well worked out, and a more specific answer is available.</p>\n\n<p>The question boils down to: <strong>How can I advance my circadian phase by 3 hours?</strong></p>\n\n<p>This is a question relevant for Eastward travel. It also comes into play during the spring time change for those who live where DST is observed as well as in the shift from weekend/holiday to weekday sleep patterns for many.</p>\n\n<p>Begin by thinking of your body’s circadian pattern on an X,Y graph¹ where:</p>\n\n<p><code>x</code>= time<br>\n<code>y</code>= activity<br>\n<img src=\"https://i.stack.imgur.com/DdHzb.png\" alt=\"graph\"></p>\n\n<p>Your goal (“phase advance”) is to shift this curve leftward by three hours along the <code>x</code> axis. </p>\n\n<p>When attempting to manipulate circadian phase, the key is to understand your body’s <a href=\"http://www.circadian.org/dictionary.html#zeitgeber\" rel=\"noreferrer\">Zeitgebers</a>.Your body intrinsically has circadian oscillators that confer the cycle and determine the period; Zeitgebers are external agents that <em>entrain</em> this oscillation by maintaining or shifting it along the <code>x</code> axis. The most powerful Zeitgeber, hands down, is <strong>light</strong>.</p>\n\n<p>Now the question is: what is the relationship between light and this curve? That turns out to be slightly complex in that the answer depends on the time in the circadian cycle during which the stimulus is applied. The relationship has been very well worked out in some <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717723/\" rel=\"noreferrer\">very cool experimental protocols</a>. Here it is:²</p>\n\n<p><img src=\"https://i.stack.imgur.com/ex2zN.png\" alt=\"enter image description here\"></p>\n\n<p>Your goal is to achieve <code>y= +3</code> (which corresponds to <code>Δ= -3</code> along the <code>x</code> axis on the first graph). You can see here that an optimal light stimulus perfectly timed is able to achieve almost a 3-hour shift in a single cycle. The optimal stimulus is going to be bright light in the blue frequency range, and the optimal timing is going to be about 2 hours before your habitual wake time. (About 45 min duration is probably just as good as a longer duration.) </p>\n\n<p>Practically, a good tip is: for two days prior to leaving, set your alarm an hour early and expose yourself to bright light (either broad-spectrum sunlight or blue light from a lightbox) for 30-45 min immediately upon waking. Each day’s exposure can be expected to achieve a 1-1.5 hour phase advance, and this protocol can be remarkably effective for mitigating the jet lag on the following day when you need to get up 3 hours prior to your habitual wake time.</p>\n\n<p><a href=\"https://health.stackexchange.com/a/510/165\">The other answer</a> mentioned melatonin. Administered exogenously, this is indeed another Zeitgeber, although much less powerful than light. Melatonin also has a phase response curve that turns out to be basically 180&#186; shifted relative to the light PRC. That is, if the optimal timing for light to phase advance is around 2 hours prior to the habitual wake time, the optimal timing for melatonin administration will be 12 hours prior to that. For most people that corresponds to 4-6 hours prior to their habitual bedtime.</p>\n\n<p>Eating and exercise are both fairly weak Zeitgebers, and I wouldn’t worry about them too much. As usual in circadian biology, <strong>it’s all about light!</strong>³ </p>\n\n<hr>\n\n<p>_{\n1. Image from: <a href=\"http://www.aasmnet.org/Resources/PracticeReviews/cpr_Actigraphy.pdf\" rel=\"noreferrer\">http://www.aasmnet.org/Resources/PracticeReviews/cpr_Actigraphy.pdf</a><br>\nAncoli-Israel et al. <em>The Role of Actigraphy in the Study of Sleep and Circadian Rhythms</em> SLEEP 2003;26(3):342-92.<br>\nThis sort of graph is obtained by plotting a cosine curve with a period of 24h using least-squares from data derived from wrist actigraphs that measure movement.\n}<br><br>\n_{\n2. Image from: <a href=\"http://en.wikipedia.org/wiki/Phase_response_curve\" rel=\"noreferrer\">http://en.wikipedia.org/wiki/Phase_response_curve</a>\n}<br><br>\n_{\n3. All of this can be found in any introduction to circadian biology and/or sleep medicine. My own textbook is:<br>\n}\n_{\n<em>Kryger MH, Roth T, Dement WC. Principles and practice of sleep medicine. 5th ed. 2011: Saunders. St. Louis, MO.</em><br>\n}\n_{\nThe review of experimental protocols from Dr. Czeisler’s lab is also excellent and is freely available from PMC: <br>\n}\n_{\nDuffy, JF. Czeisler, CA. <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717723/\" rel=\"noreferrer\"><em>Effect of Light on Human Circadian Physiology</em></a> Sleep Med Clin. 2009 Jun; 4(2): 165–177.\n}</p>\n\n<hr>\n\n<p>_{\nN.B. ! Melatonin or light administered at the wrong time does the exact opposite. Although a three-hour phase shift is fairly easy to manage by predicting the phase of the PRC based on prior sleep habits, this starts to become more complicated in larger shifts. This is especially problematic in the case of Eastward travel >5h, when morning light at the destination ends up falling within the <em>negative</em> phase of the PRC and therefore <em>delays</em> the circadian curve. This is the <strong>wrong thing</strong> in this setting and is a common reason for protracted jet lag. Here, it is actually avoidance of morning light that is desired. This is complicated!\n}</p>\n", "score": 15 }, { "answer_id": 510, "body": "<h3>Body's biological clock</h3>\n\n<p><img src=\"https://i.stack.imgur.com/Wkoqt.png\" alt=\"Biological clock human\"></p>\n\n<p>^{Credits: <a href=\"https://en.wikipedia.org/wiki/Circadian_rhythm\" rel=\"noreferrer\">A circadian rhythm</a> at Wikipedia}</p>\n\n<p>There are two main hormones which plays important role in sleep.</p>\n\n<ul>\n<li><p>Melatonin (also called a youth hormone) which is produced at night which plays a fundamental role in your body's biological clock (it governs the entire sleep and wake cycle).</p></li>\n<li><p>Serotonin (“feel good” hormone) which affects wakefulness and our mood. Low levels (depression, fatigue).</p></li>\n</ul>\n\n<p>When you are going sleep, your serotonin levels are converted into sleep-promoting melatonin by the body.</p>\n\n<p>Usually body adjust to irregular sleep patterns (such as changing time zones) naturally, but it takes some time.</p>\n\n<p>However if your body has a problem of adjusting to new pattern, you may considering regulating your biological clock.</p>\n\n<p>Either by:</p>\n\n<ul>\n<li>consider taking a melatonin (1mg or 3mg, usually sold freely over-the-counter) which in general it is considered to be effective and safe (as it's naturally occurring hormone) for short term use and long-term use of up to 12 months^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23044640\" rel=\"noreferrer\">2012</a>},</li>\n<li>learn how to fall asleep naturally by reprogramming your brain and internal body clock to the new routine.</li>\n</ul>\n\n<h3>Sleep well</h3>\n\n<p>Sleep is important for our health and lack of sleep can put give you tiredness, fatigue and you're also increasing risk of serious medical conditions.</p>\n\n<p>When planning your activities and rest, you should consider around 8 hours of good quality sleep a night to function properly (some of us need more or less time).</p>\n\n<h3>Take a nap</h3>\n\n<p>If you have a disturbed sleep patterns (such as irregular work times, night shifts) and you can't afford a good quality sleep, you can have a nap (<a href=\"https://en.wikipedia.org/wiki/Power_nap\" rel=\"noreferrer\">a power nap</a>) during the day when you get tired, it helps a lot. The benefits of napping could be best obtained by training the body and mind to awaken after a short nap. Naps of fewer than 30 minutes restore wakefulness and promotes performance and learning^{<a href=\"http://www.co-internalmedicine.com/pt/re/cointernalmed/abstract.00132980-200702000-00014.htm\" rel=\"noreferrer\">2007</a>, <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/18275549\" rel=\"noreferrer\">2008</a>}.</p>\n\n<h3>Relax your mind and body</h3>\n\n<p>Before going sleep, it's important to create an environment which can help you to sleep by relaxing your mind and body, and everyone have their own way, so here are some suggestions:</p>\n\n<ul>\n<li>try to avoid TV, radio, using mobile or reading a book which can distract your mind,</li>\n<li>turn of the light, draw the curtains, limit exposure to artificial light (it suppresses production of melatonin)^{<a href=\"https://en.wikipedia.org/wiki/Light_effects_on_circadian_rhythm\" rel=\"noreferrer\">wiki</a>},</li>\n<li>take a warm bath (it'll reach a temperature that's ideal for rest),</li>\n<li>do some physical exercises:\n\n<ul>\n<li>relaxation exercises to relax your muscles (such as yoga),</li>\n<li>vigorous physical activity (sex makes us sleepy as well),</li>\n</ul></li>\n<li>try to listen to hypnotic music and sound effects to relax,</li>\n<li>medication can help with sleeping problems,</li>\n<li>write \"to do\" list for the next day to clear your mind of any distractions.</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/livewell/insomnia/pages/bedtimeritual.aspx\" rel=\"noreferrer\">How to get to sleep</a> at NHS}</p>\n\n<p>Read more:</p>\n\n<ul>\n<li><a href=\"http://www.nhs.uk/livewell/sleep/pages/sleep-home.aspx\" rel=\"noreferrer\">Better sleep: How to get to sleep</a> at NHS</li>\n<li><a href=\"http://www.nhs.uk/Livewell/tiredness-and-fatigue/Pages/self-help-energy-tips.aspx\" rel=\"noreferrer\">Self-help tips to fight fatigue</a> at NHS</li>\n</ul>\n", "score": 6 } ]

[ "sleep" ]

[ { "answer_id": 152, "body": "<p>Your body uses motion in several ways to maintain function.\nOne of them is called muscle milking\nMuscle Milking is the process where blood is pushed back up to your heart by your muscles compressing on the veins. Since the veins have valves to ensure one-way direction, compression (usage) of the muscles causes it to move up, against gravity.</p>\n\n<p>Lymph also piggybacks on this process to push fluid upwards, otherwise occasionally resulting in edema.</p>\n\n<p>Movement of blood is incredibly important. It transports white blood cells to fight various infections in your body, platelets have a tendency to start clotting when blood is moving too slow for a extended period of time (however are extremely important in injuries), nutrients are carried from your intestines, oxygen is carried to cells and carbon dioxide is carried away, filtering by the kidney's, etc.</p>\n\n<p>Another component is the the body's powerful ability to adapt. It doesn't like spending energy when it doesn't have to. Sitting for extended periods of time frequently means your heart doesn't need to be very strong. Should at some point you do need it to do more (like when you're standing or exercising) it must quickly work overtime to keep up. This invites high blood pressure, dizziness and general fatigue.</p>\n\n<p>To push the point, imagine someone who has been bed-ridden for several weeks due to surgery, illness, etc. While in supine (lying on your back) the person may feel fine. However when sitting up the person experiences dizziness, light-headedness and occasionally nausea. Overtime, especially following exercises, the symptoms fade as the body adjusts to being in a sitting position. The same occurs when standing</p>\n\n<p><strong>What to do</strong></p>\n\n<p>The solution is simple. Move. Work out so that periods of inactivity are the exception and not the norm. A strong heart can handle higher level exercises and inactivity. A weak heart will have trouble with the former.</p>\n\n<p>Also, it's the inactivity with sitting that is unhealthy. You can stand and be inactive just as well (standing desk). </p>\n\n<p>@kevin</p>\n\n<blockquote>\n <p>I have heard people who, after a long flight, fainted as they get up after landing.</p>\n</blockquote>\n\n<p>The blood vessels constantly vaso dilate (get wider) and vaso constrict as needed.\nFollowing a nights sleep, you may feel dizzy if you quickly stand up. This is because over the course of the night you were likely sitting in supine. Since only minimal pressure is needed to maintain flow in supine, the vessels can vaso dilate. </p>\n\n<p>Upon standing or sitting, the situation changes quickly and the body is not quick enough to respond. Since the body cannot get blood to the highest point (brain) fast enough, it cannot function. Luckily, when people faint they go into a horizontal posture, rapidly providing blood to the brain again.</p>\n\n<p>The above invites trauma of course, but the risk of trauma is less of a issue then the lack of nutrients to the brain.</p>\n", "score": 14 }, { "answer_id": 137, "body": "<p>Sitting for long periods of time is unhealthy because you do not get good blood circulation. Most of your muscles are not moving. Passengers are recommended to get up and walk around on a long haul flight every few hours for the same reason.</p>\n\n<p>In serious cases, the blood may clot in the legs. This is known as <em>deep vein thrombosis</em>. I have heard people who, after a long flight, fainted as they get up after landing. This is because there was insufficient blood pressure to carry nutrition to the brain.</p>\n\n<p>If you use a bad sit posture, it may lead to back pains as well.</p>\n", "score": 4 }, { "answer_id": 3491, "body": "<p>Not moving your joints can increase pain in bones and arthritis.\nIt also has an effect on your mental state. Without any change in your surroundings and staying in the same environment can cause depression, increase stress and anxiety. </p>\n\n<p>It can also increase tiredness and feeling sluggish, so if you're at work it can have an effect on your work and the overall workplace.</p>\n\n<p>And the biggest is weight gain!</p>\n", "score": 0 } ]

[ "posture" ]

[ { "answer_id": 18673, "body": "<p>If there was close contact, if the 90% rate is accurate, and if occurrence is independent in related individuals, then you would expect 0.10 * 0.10 = 1% of contacts with 2 potentially vulnerable people to result in neither person infected.</p>\n\n<p>1% sounds rare, but <em>rare events happen all the time</em>, and 1% isn't even particularly rare. If you know 100 families, you'd expect this outcome to happen on average in 1 of them.</p>\n\n<p>That's not very unusual and is clearly plausible just from the information you have at hand. As @DeNovo mentioned in a comment, it is also likely that the spread is <em>not</em> independent, because the children share several characteristics: they are related, so they share: </p>\n\n<ul>\n<li>any genetic component to vulnerability </li>\n<li>any characteristics of the father's illness such as the level of virus replicating in the father's lungs</li>\n<li>perhaps the level of actual contact with the father and how well he may be effectively quarantined from the others</li>\n</ul>\n\n<p>Those factors could make the joint probability across the two children closer towards the 10% rate for a single individual: once you know if the first child is infected or not infected, you can make a better guess about the second child based on all the possible shared characteristics of the children or the infected person.</p>\n", "score": 33 }, { "answer_id": 18674, "body": "<p>To add to @BryanKrause's answer re: rare events happen all the time, the children are not out of the woods yet. The mean incubation time for a primary VZV infection (the clinical syndrome known as chicken pox) is 14 days, but often lasts up to 21 days (see Murray Medical Microbiology, Ch. 53). The father is infectious while shedding virus, usually via the lungs. This correlates with the period of time a patient is febrile. I wouldn't say the father didn't infect his children until he has been afebrile for 21 days. </p>\n", "score": 14 }, { "answer_id": 18685, "body": "<p>Apart from not getting infected due to pure chance (as mentioned already) there is one highly probable explanation (<em>explanation</em>, not overall chance).</p>\n<p>People get, but don't show it:</p>\n<p><strong>asymptomatic infection</strong></p>\n<blockquote>\n<p>Asymptomatic infection is unusual, but some cases are so mild, they go unrecognised. The primary viraemic phase is followed by a secondary viraemia to the skin and the mucosal surfaces.</p>\n<p><a href=\"https://www.gponline.com/chickenpox-varicella-zoster-clinical-review/infections-and-infestations/viral-infections/article/1284872\" rel=\"noreferrer\">Chickenpox (varicella zoster) - Clinical Review, GP-online, 2014</a></p>\n</blockquote>\n", "score": 8 } ]

[ "infection", "vaccination", "virus", "infectious-diseases", "chickenpox" ]

[ { "answer_id": 29347, "body": "<p>If you think about prosthetic devices, the answer will soon become clear. You would not wish to have your thigh bone extended by an extra six or eight inches (about the minimum distance that one could practically strap it to) and have the new joint that much lower than the natural knee of the other leg.</p>\n<p>Neither would it work well to extend the leg clear to the foot/ankle point without a knee joint at all.</p>\n<p>Cutting the bone roughly midway between joints is the most practical way of enabling the amputee to restore some function via a prosthesis.</p>\n", "score": 20 }, { "answer_id": 29353, "body": "<p>The bone cut must be proximal enough to perform a myodesis (anchoring the muscle through drill holes near the cut end of the bone) or myoplasty (suturing the fascia of antagonistic muscles together) and allow the flaps to cover the end of the femur without tension.</p>\n<p>The incision can not simply be moved lower to address the problem of flap coverage because now you are essentially trying to cover an above knee amputation with below knee amputation flaps. There is likely a good reason an above knee amputation was selected in the first place (perhaps inadequate below knee perfusion) and thus it would be unwise to rely on these poorly perfused flaps to adequately heal.</p>\n", "score": 10 }, { "answer_id": 29355, "body": "<p>Because every piece of biological function that can be retained is one less act for the patient to re-learn and for a prosthetic to replicate.</p>\n<p>Removing a patient's knee and below means a more expensive artificial limb with more joints compared to foot removal only.</p>\n<p>By retaining the operating knee joint where possible allows the patient as much function as they can have to assist with recuperation, both physical and mental.</p>\n<p>Additionally, the knee is a weight bearing joint when assembled. The bare bottom end of the femur is not well-suited to taking loads when not mated with the rest of the knee.</p>\n<p>And there is less flesh in this area, so the blood supply is not conducive to growing healthy flesh over the stump either. When the leg is cut above the knee, the bone is cut a little higher and the thigh muscle/flesh is used to cover the stump. There is far less meat in the knee to close the hole.</p>\n<p>(source, my Grandad had a foot removed. He'd also had a steel knee installed earlier, which limited blood flow to the stump and it simply starved. So he had an above-knee amputation and could not adjust to a longer leg, ended up in a wheelchair for the rest of his life.)</p>\n", "score": 3 } ]

[ "surgery", "bones", "knee", "amputation" ]

[ { "answer_id": 30854, "body": "<p>The short version is that in 2016 the polio vaccine changed.</p>\n<p>A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus is usually harmless, it reproduces in the gut and spreads through a fecal-oral route. In ~99% of infections it only causes mild diarrhea. In the remaining 1% of cases, however, it gets into the bloodstream and from there enters nerves, causing paralysis and/or respiratory failure. There are two types of vaccine: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). IPV is a shot of killed virus particles and provides systemic immunity; someone who gets IPV but not OPV can still be infected with and spread polio virus, but they are protected from serious disease. OPV is a pill of live virus that has been mutated so it can reproduce in the recipient's gut but cannot get into nerves to cause disease. Someone who gets a full course of OPV will have mucosal immunity to polio virus - they will not be able to spread it. In areas with unsanitary water supplies, OPV is necessary to eradicate wild polio. However, the vaccine strains reproduce in and are excreted by the treated individual for 4-6 weeks, and can end up in the water supply, where they can infect new individuals. This wouldn't matter, except that the mutations that prevent the vaccine-strain virus from entering nerves eventually get reversed by new mutations. Unvaccinated people can then get sick from the circulating vaccine-derived polio virus.</p>\n<p>There are three types of wild polio virus, so three strains of vaccine are needed to provide protection. The version of OPV administered before 2016 was &quot;trivalent&quot; - it included 3 vaccine strains to protect against 3 types of polio, while the new version is &quot;bivalent&quot; - it includes 2 vaccine strains. The switch was made because the excluded type, type 2, has been successfully eradicated in the wild, and the live vaccine against that type is the one that was mutating to regain its ability to cause paralysis. This &quot;reverted&quot; type 2 live vaccine is still circulating and there is a large and increasing group of people who have no immunity to it, hence the boom.</p>\n<p>The OPV switch was supposed to be accompanied by a stepped-up vaccination program to eradicate the live type 2 vaccine strain, but a shortage of the needed vaccines, wars, and other difficulties prevented this. Also, the ability of the vaccine-derived strains to remain circulating in communities after vaccination stopped was underestimated.</p>\n<p>The reasons for the sharp increase in circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks following the OPV switch are discussed in greater detail in <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8393165/\" rel=\"noreferrer\">this report in China CDC weekly</a>. A new vaccine against type 2 polio that is more genetically stable (and therefore less likely to revert to disease-causing strain through mutation) <a href=\"https://polioeradication.org/news-post/independent-experts-advise-transition-to-next-use-phase-for-novel-oral-polio-vaccine-type-2-nopv2/\" rel=\"noreferrer\">became available March 2021</a>. I was not able to find a good answer to how effective the response to all this has been, but adding up all the 2021 cVDPV cases for the countries listed at <a href=\"https://polioeradication.org/where-we-work/\" rel=\"noreferrer\">https://polioeradication.org/where-we-work/</a> gives a total of 635. Some cases are listed for 2022, so the 2021 count is likely close to complete. If so, cVDPV is no longer booming.</p>\n", "score": 37 } ]

[ "vaccination", "infectious-diseases" ]

[ { "answer_id": 229, "body": "<h3>Marijuana as medicine</h3>\n<p>Its usage in modern times is controversial, however studies of chemicals in the plant (<a href=\"https://en.wikipedia.org/wiki/Cannabinoid\" rel=\"noreferrer\">cannabinoids</a> such as <a href=\"https://en.wikipedia.org/wiki/Tetrahydrocannabinol\" rel=\"noreferrer\">THC</a>, <a href=\"https://en.wikipedia.org/wiki/Cannabidiol\" rel=\"noreferrer\">CBD</a>) has lead to two FDA-approved medications and more research may lead to more medications.</p>\n<p>Marinol which has been approved by FDA is used for the treatment of anorexia in HIV/AIDS patients as well as for nausea and vomiting of patients undergoing chemotherapy^{<a href=\"https://en.wikipedia.org/wiki/Tetrahydrocannabinol#Marinol\" rel=\"noreferrer\">wiki</a>}.</p>\n<p>THC increases appetite and reduces nausea. It may also decrease pain, inflammation and muscle control problems. CBD does not affect the mind, but it can be useful in reducing pain and inflammation, controlling epileptic seizures and possibly treating mental illness and addictions^{<a href=\"http://dailycaller.com/wp-content/uploads/2015/04/df_ismarijuanamedicine_4_2015.pdf\" rel=\"noreferrer\">NIH 2014</a>}.</p>\n<h3>Treatment for cancer</h3>\n<p>Marijuana (whole unprocessed plant or its basic extracts) kills cancer cells and it has been confirmed by US government. The federal government funded research was carried by <a href=\"https://en.wikipedia.org/wiki/National_Institute_on_Drug_Abuse\" rel=\"noreferrer\">NIDA</a> and the publication admits that cannabis has medicinal value^{<a href=\"http://dailycaller.com/wp-content/uploads/2015/04/df_ismarijuanamedicine_4_2015.pdf\" rel=\"noreferrer\">2014</a>}:</p>\n<blockquote>\n<p>Recent animal studies have shown that marijuana can kill certain cancer cells and reduce the size of others.</p>\n<p>Evidence from one animal study suggests that extracts from whole-plant marijuana can shrink one of the most serious types of brain tumors.</p>\n<p>Research in mice showed that these extracts, when used with radiation, increased the cancer-killing effects of the radiation.</p>\n</blockquote>\n<p>The U.S. Food and FDA conducted studies to determine the benefits and risks, however not recognized or approved marijuana plant as medicine for cancer, because researchers did not conducted enough large-scale clinical trials which showed the health benefits.</p>\n<p>A molecular biologist from Spain, Dr. Christina Sanchez explains has been studying the anti-tumor effects of THC for over a decade and she explains how it kills cancer cells entirely. See the <a href=\"https://vimeo.com/83094404\" rel=\"noreferrer\">video</a> for more details.</p>\n<h3>Health benefits</h3>\n<p>Other potential health benefits can include:</p>\n<ul>\n<li><p>Cannabinoids as antioxidants and neuroprotectants.</p>\n<p>Patent <a href=\"http://www.google.com/patents/US6630507\" rel=\"noreferrer\">US6630507</a> by 3 scientists from the Department of Health and Human Services which describe in abstract:</p>\n<blockquote>\n<p>Cannabinoids have been found to have antioxidant properties, unrelated to NMDA receptor antagonism. This new found property makes cannabinoids useful in the treatment and prophylaxis of wide variety of oxidation associated diseases, such as ischemic, age-related, inflammatory and autoimmune diseases. <strong>The cannabinoids are found to have particular application as neuroprotectants, for example in limiting neurological damage following ischemic insults, such as stroke and trauma, or in the treatment of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and HIV dementia.</strong> Nonpsychoactive cannabinoids, such as cannabidoil, are particularly advantageous to use because they avoid toxicity that is encountered with psychoactive cannabinoids at high doses useful in the method of the present invention.</p>\n</blockquote>\n</li>\n<li><p>Nonpsychoactive CBD anti-tumor activity.</p>\n<p>Study published in the journal <a href=\"http://mct.aacrjournals.org/content/10/1/90.abstract\" rel=\"noreferrer\">Molecular Cancer Therapeutics</a> state that cannabis having anti-tumor effects and found it could be the answer to the increasing number of treatment-resistant cancers.</p>\n<p>Italian researchers published a study in <a href=\"http://jpet.aspetjournals.org/content/308/3/838.abstract\" rel=\"noreferrer\">The Journal of Pharmacology and Experimental Therapeutics</a> which tested cannabidiol on human brain tumor cells and they've found that the non-psychoactive cannabis compound to have detrimental effects on the viability of these cells, inhibiting their growth “significantly”.</p>\n</li>\n<li><p>Antiproliferative action on brain tumour cells.</p>\n<p>A study found in the <a href=\"http://www.nature.com/bjc/journal/v95/n2/abs/6603236a.html\" rel=\"noreferrer\">British Journal of Cancer</a> found that THC and other cannabinoids were able to inhibit the growth of brain tumors. In two out of nine patients, the compounds were able to decrease the number of tumor cells, all without psychoactive effects.</p>\n</li>\n<li><p>The cannabinoid system can serve to protect the brain against neurodegeneration.</p>\n<p><a href=\"http://www.jneurosci.org/content/21/17/6475.abstract\" rel=\"noreferrer\">The Journal of Neuroscience</a> contains another study from 2001 in which THC-treated rats received neuro-protective benefits. Neuro-degeneration refers to progressively worsening brain function commonly found in age-related dementia but also when the brain is damaged. The researchers found that rats treated with THC were protected against such damage, indicating it as a potential solution for slowly progressive neurodegenerative disease and also acute damage that could occur as a result of directed tumor treatment.</p>\n</li>\n<li><p>Antibacterial effects of cannabinoids</p>\n<p>A 2008 <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/18681481\" rel=\"noreferrer\">study</a> led by Appendino et al. demonstrated that cannabinoids have antibacterial activity even on MRSA. They stated that:</p>\n</li>\n</ul>\n<blockquote>\n<p>All five major cannabinoids (cannabidiol (1b), cannabichromene (2), cannabigerol (3b), Delta (9)-tetrahydrocannabinol (4b), and cannabinol (5)) showed potent activity against a variety of methicillin-resistant Staphylococcus aureus (MRSA) strains of current clinical relevance.</p>\n</blockquote>\n<hr />\n<p>As a side note, in Hindu texts cannabis was known as ‘sacred grass’. It has also been used in traditional Chinese medicine for centuries.</p>\n<hr />\n<p>Read more:</p>\n<ul>\n<li><a href=\"http://www.drugabuse.gov/publications/drugfacts/marijuana-medicine\" rel=\"noreferrer\">What is medical marijuana?</a> at Drug Abuse</li>\n<li><a href=\"https://www.whitehouse.gov/ondcp/marijuanainfo\" rel=\"noreferrer\">Marijuana Resource Center</a> at White House</li>\n<li><a href=\"http://www.collective-evolution.com/2013/08/23/20-medical-studies-that-prove-cannabis-can-cure-cancer/\" rel=\"noreferrer\">20 Medical Studies That Show Cannabis Can Be A Potential Cure Cancer</a></li>\n<li><a href=\"http://naturalsociety.com/4-studies-marijuana-treat-brain-cancer/\" rel=\"noreferrer\">4 Studies Proving That Marijuana Can Treat Brain Cancer</a>,</li>\n<li>Documentary: <a href=\"http://topdocumentaryfilms.com/run-from-the-cure/\" rel=\"noreferrer\">Run From The Cure</a> - The Rick Simpson Story - made by Christian Laurette in 2008</li>\n<li><a href=\"http://naturalsociety.com/molecular-biologist-explains-thc-kills-cancer-completely/\" rel=\"noreferrer\">Molecular Biologist Explains How THC Kills Cancer Completely</a></li>\n<li><a href=\"https://www.hempforfuture.com/2014/04/11/recipe-to-make-cannabis-oil-for-chemo-alternative/\" rel=\"noreferrer\">Recipe To Make Cannabis Oil For Chemo Alternative</a></li>\n<li><a href=\"http://www.hightimes.com/read/rick-simpsons-hemp-oil-medicine\" rel=\"noreferrer\">Rick Simpson's Hemp-Oil Medicine</a></li>\n</ul>\n", "score": 14 } ]

[ "medications", "recreational-drugs" ]

[ { "answer_id": 63, "body": "<p>There seems to be a link (as one would expect) between areas with a higher concentration of unvaccinated individuals and disease outbreaks (see <a href=\"http://www.theverge.com/2014/1/21/5329478/vaccine-preventable-disease-outbreaks-show-anti-vaccine-movement-influence\">this article</a> and the <a href=\"http://www.cfr.org/interactives/GH_Vaccine_Map/#map\">source data map</a>).</p>\n\n<p>The recent (2015) measles outbreaks in California are a good example: at least 70-80% of those infected were unvaccinated (including a number of newborns too young to be vaccinated).</p>\n\n<blockquote>\n <p>State officials say that 28 were not vaccinated at all, one was partially vaccinated and five were fully vaccinated. Six of the unvaccinated were babies, too young to be vaccinated.\n (<a href=\"http://www.npr.org/blogs/health/2015/01/22/379072061/disneyland-measles-outbreak-hits-59-cases-and-counting\">source</a>)</p>\n</blockquote>\n\n<p>Simply put, unvaccinated individuals are more likely to be carrying a vaccine-preventable disease compared to the rest of the population. If your newborn is not vaccinated yet he or she is at risk. In the case of measles or whooping cough, an infection could turn deadly, as can many others.</p>\n\n<p>I'm not an expert in pathology, nor am I a parent, but I would at the very least <strong>not</strong> let these individuals hold or come near your newborn, and would preferably keep my newborn completely away from them until a later time.</p>\n", "score": 15 } ]

[ "vaccination", "infant" ]

[ { "answer_id": 409, "body": "<p>The quoted \"1-2\" pounds per week (or approximately 0.5 - 1 kilo) is based on the traditional 3500 calories burned = 1 pound of fat. Now, while the exact figure of 3500 calories is somewhat open to debate, that is the rationale. 500 calories a day = 1 pound of loss per week.</p>\n\n<p>The problem with crash dieting is twofold. One, the majority of the weight lost is water weight, and will rapidly return once the person hydrates themselves. The second problem is that in an effort to lose large amounts of weight in a short time is that people will essentially starve themselves, and possibly do so while adding in exercise.</p>\n\n<p>In the very short term, this may not pose any problems for a healthy person, but if the dieter is compromised in any way health wise, or the practice is continued for a longer period then nutrient deficiencies can start arising, which can introduce a long litany of health problems.</p>\n\n<p>Another problem is that people that lose large amounts of weight in a short time tend to binge eat once the diet period is over, and regain most if not all the weight. Many even end up weighing more than they did before they did the extreme dieting.</p>\n\n<p>There have been studies comparing many of the popular diets such as Atkins, South Beach, China Study, Paleo, and on and on. They have all shown that weight loss is a simple factor of calorie reduction. Eat less calories than you expend, and you will lose weight. Period. (And \"starvation mode\" is a myth.) When you first start dieting, you may lose more than the 1-2 pounds a week, which is normal. After a bit, your body will readjust and the weight loss will slow down, however if you maintain the calorie deficit, you will eventually lose the weight.</p>\n\n<p>As requested:</p>\n\n<p><a href=\"http://www.nejm.org/doi/full/10.1056/nejmoa0804748\">New England Journal of Medicine</a></p>\n\n<p><a href=\"http://annals.org/article.aspx?articleid=668717\">Annals of Internal Medicine</a> (Short abstract)</p>\n\n<p><a href=\"http://www.sciencedirect.com/science/article/pii/S0002822398000935\">Journal of the American Dietetic Assn.</a></p>\n\n<p><a href=\"http://www.sciencedirect.com/science/article/pii/S0140673604169869\">The Lancet</a> (Not a study, but references two studies)</p>\n\n<blockquote>\n <p>A systematic review of low-carbohydrate diets found that the <strong>weight loss achieved is associated with the duration of the diet and restriction of energy intake</strong>, but not with restriction of carbohydrates. Two groups have reported longer-term randomised studies that compared instruction in the low-carbohydrate diet with a low-fat calorie-reduced diet in obese patients (N Engl J Med 2003; 348: 2082–90; Ann Intern Med 2004; 140: 778–85). <strong>Both trials showed better weight loss on the low-carbohydrate diet after 6 months, but no difference after 12 months.</strong></p>\n</blockquote>\n", "score": 17 }, { "answer_id": 4131, "body": "<p>I want to add an answer focusing on the second part of your question </p>\n\n<blockquote>\n <p>in what way is losing weight faster than this unhealthy</p>\n</blockquote>\n\n<p>There's a few unhealthy things that can happen to people who lose a lot of weight quickly. It's of course subjective what rapid is. The most severe effects can be seen in people on very low calorie diets (VLCD). </p>\n\n<p>Gallstones develop significantly more often in people losing weight rapidly, often requiring surgery. Thus is linked to not getting enough fat from food. </p>\n\n<blockquote>\n <p>In an early study, gallstones developed in 25% of patients during 8 weeks of VLCD, and 6% of patients eventually required cholecystectomy (19). In a second trial, asymptomatic gallstones occurred in ∼12% of patients within 6 months of starting a VLCD, and approximately one-half of these individuals eventually became symptomatic, requiring cholecystectomy</p>\n</blockquote>\n\n<p>Another risk is \"simple\" malnutrition. Not getting enough food leads to not getting enough nutrients. </p>\n\n<p>There can be cardiac complications, hairloss, dizziness, constipation, and muscle cramps. </p>\n\n<p>Very low calorie diets are of course far from the normal way people diet. But they show what <em>can</em> happen. </p>\n\n<p>Source: <a href=\"http://onlinelibrary.wiley.com/doi/10.1038/oby.2006.146/full\" rel=\"nofollow\">The Evolution of Very-Low-Calorie Diets: An Update and Meta-analysis</a></p>\n", "score": 4 } ]

[ "nutrition", "diet", "weight" ]

[ { "answer_id": 830, "body": "<p>This is a pretty old old-wives tale, taking many forms: don't go out into the cold while it's raining, or without a hat, with wet hair, without a warm coat or scarf, without boots, etc., \"or you'll catch your death of cold.\"</p>\n\n<p>The old wive's tale was immortalized by Jane Austin in her book, <em>Pride and Prejudice</em>, when the heroine's sister Jane falls ill after getting a soaking in the rain.</p>\n\n<p>This has been studied extensively. A New York Times article describes one such uncomfortable-sounding study:</p>\n\n<blockquote>\n <p>In the 1950's, Chicago researchers repeated the experiment on a larger scale with several hundred volunteers sitting in their socks and underwear in a 60-degree room before being inoculated with infectious mucus. Others, in coats, hats and gloves, spent two hours in a large freezer. The conclusion: all 253 chilled volunteers caught cold at exactly the same rate as 175 members of a warm control group. </p>\n</blockquote>\n\n<p>In other words, being cold had no effect on <em>catching</em> a cold.</p>\n\n<p>A 1968 experiment studied the effect of (among other methods of chilling) a cold water bath at several stages during and after inoculation with rhinovirus (one of the many viruses responsible for the common cold). No effect.</p>\n\n<p>Yet the studies continue, because anything shown to decrease the incidence of the common cold would be beneficial to the sufferers, as in the US alone, 75 to 100 million physician visits are due to the common cold, and millions of days are lost from school and work.</p>\n\n<p>But what has never been proven is that getting chilled in any way causes one to come down with a cold.</p>\n\n<p>_{<a href=\"http://www.nytimes.com/2003/03/04/science/you-ll-catch-your-death-an-old-wives-tale-well.html\">'You'll Catch Your Death!' An Old Wives' Tale? Well...</a>}<br>\n_{<a href=\"http://www.nejm.org/doi/full/10.1056/nejm196810032791404\">Exposure to Cold Environment and Rhinovirus Common Cold — Failure to Demonstrate Effect</a>}<br>\n_{<a href=\"http://scholar.google.com/scholar?hl=en&amp;q=effect+of+body+temperature+and+rhinovirus+infection&amp;btnG=&amp;as_sdt=1%2C39&amp;as_sdtp=\">Acute cooling of the body surface and the common cold</a>} </p>\n", "score": 14 }, { "answer_id": 845, "body": "<p>This is an old wives tale. Being cold in and off itself will not cause you to catch a cold because a cold is viral. <a href=\"http://io9.com/does-being-cold-make-you-more-susceptible-to-catching-c-510314172\" rel=\"noreferrer\">3</a></p>\n\n<p>However, being cold for a long time can lower your immune response and if your system was already fighting a cold then symptoms may present that were not needed before. This is because your scored an own goal when you lowered your immune response.</p>\n\n<p>So that possible miss-attribution aside (you already had a cold but did not know it) no, being cold will not cause you to become ill... unless you stay so cold that your body starts to shut down.</p>\n\n<p>One study</p>\n\n<blockquote>\n <p>[...] found that the cells stored at 98.6 degrees launched a more robust immune attack than the ones at 91 degrees. <a href=\"http://blogs.discovermagazine.com/d-brief/2015/01/06/catch-cold-being-cold/#more-9526\" rel=\"noreferrer\">1</a> </p>\n</blockquote>\n\n<p>That study was published in the Proceedings of the National Academy of Sciences. <a href=\"http://www.pnas.org/cgi/doi/10.1073/pnas.1411030112\" rel=\"noreferrer\">4</a></p>\n\n<blockquote>\n <p>A study at the Common Cold Centre in Cardiff found that people who chilled their feet in cold water for 20 minutes were twice as likely to develop a cold as those who didn't chill their feet. <a href=\"http://www.nhs.uk/Livewell/coldsandflu/Pages/Preventionandcure.aspx\" rel=\"noreferrer\">2</a></p>\n</blockquote>\n", "score": 7 }, { "answer_id": 827, "body": "<p>My experience has been that when I, or someone in my family, gets chilled, this seems to increase the chance of coming down with a cold. I tried searching on google for this, and found <a href=\"http://blogs.discovermagazine.com/d-brief/2015/01/06/\" rel=\"nofollow\">this article</a>, which says:</p>\n\n<blockquote>\n <p>in mouse airway cells, rhinovirus replicates preferentially at nasal cavity temperature due, in part, to a less efficient antiviral defense response of infected cells at cool temperature.</p>\n</blockquote>\n\n<p><a href=\"http://pnas.org/content/112/3/827\" rel=\"nofollow\">Here</a> is the abstract of the study they were talking about.</p>\n", "score": 5 } ]

[ "immune-system", "infection", "common-cold" ]

[ { "answer_id": 3576, "body": "<p>Dental flossing, essentially is done to <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22161438\">maintain periodontal health</a>, in hard to reach areas. Areas which are not used to any \"friction\" so, they will react in a rather singular manner in comparison to our exposed gums, per say. Thus, providing you presently have good oral health i.e. you don't have gingivitis which causes <a href=\"https://www.nlm.nih.gov/medlineplus/ency/article/003062.htm\">bleeding</a> of the gums amidst brushing. </p>\n\n<p>Initially, flossing will cause inflammation and minor bleeding however, if the bleeding is rather severe it could indicate a periodontal disease and require medical intervention. Gums, if they are \"virgins\" to interdental flossing scene, will be <a href=\"http://www.nhs.uk/chq/Pages/2379.aspx?CategoryID=74\">tender</a>, and this is common amongst nearly all whom who haven't flossed. So, despite your concern, they will become more firm once the plaque has been plausibly removed. As your gums become less tender, they will hence become less sensitive and no longer bleed as you floss. </p>\n\n<p>Albeit, if the bleeding still prevails after a period of a week, it would be advised to either, refresh your knowledge on <a href=\"http://www.ada.org/~/media/ADA/Science%20and%20Research/Files/watch_materials_floss.ashx\">how to floss</a>, or pay a visit to your dentist. The latter could conclude that, you are incorrectly flossing e.g. too much pressure and rigor. </p>\n\n<p>It's difficult to judge when you'll become apparent of the benefits since, the greatest improvements will initially happen beyond your eye's magnification. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22161438\">This</a> study may cure your curiosity, though. </p>\n", "score": 10 } ]

[ "dentistry" ]

[ { "answer_id": 1431, "body": "<p>There are two mechanisms of action how light affect humans discussed here:</p>\n\n<ol>\n<li>Amount of energy: shorter (blue) wavelengths are more energetic than lower (red), so it can be assumed that they damage photoreceptors more.</li>\n<li>Psychological: bluish light is associated with day by our biochemistry. Higher amounts of bluish light makes our brains more awake (e.g. suppressing production of melatonin)</li>\n</ol>\n\n<p>Point 1 leaves conclusion that reducing amount of blue light from the monitor is always a good thing, while point 2 means that it's helpful as you plan to go to sleep. From my experience I can say that #2 is very true, as dim and warm light in the workplace made me sleepy and inefficient. Changing light sources to bright and cool fluorescent lights helped a lot. Also I've installed RGB led lighting in my living room and discovered that using only red light at the end of the day makes falling asleep easier. Just looking at BenQ's idea it certainly appeals to me.</p>\n\n<p>However, the purpose of a monitor is to reproduce colors accurately. The question remains if the amount of blue can be reduced without affecting either color balance or just lowering brightness altogether. Modern \"white\" LEDs commonly used as source of light in LCD monitors are primarily blue light sources with some yellow phosphorus thrown in to balance out main emission. If BenQ used different kind of LEDs of CCFLs (less bluish) then this technology could not be turned on and off, much less adjusted. To truly limit the amount of certain component on the fly, RGB-LEDs would have to be used as backlight (they are not used here, and I'm not aware of any affordable monitor with RGB LEDs). What is presented on the video seems like simply changing color temperature to a warmer one - which is available in almost every color monitor. Even if it's not plain old color temperature, but something more sophisticated, e.g. clamp on blue channel in gamma ramp then same effect can still be achieved in software, in graphic card's gamma settings.</p>\n\n<p>I disagree much with the video on the site you've linked. Even layman like me can easily point out errors:</p>\n\n<ol>\n<li>Saying that blue light is almost as bad as UV light just because it sits next to it on a spectrum is plain scaremongering. The biggest danger of UV comes from the fact that human eye can't see UV, so it won't close the iris to block it. The eye may \"think\" it's dark in very bright UV light and let it all in. Blue light, as part of visible spectrum, does not present this danger.</li>\n<li>The picture of blue-violet going \"deep into your eye\" is laughable. It shows other parts of spectrum stop at the lens while only blue reaches retina. It's plain lie, of course. Red and green do reach the retina just as well, otherwise we wouldn't be able to perceive them.</li>\n</ol>\n\n<p>Bottom line: <strong>I think that the idea of reducing amount of blue light is good, but BenQ's execution is just a marketing gimmick or not much more</strong> in the best case.</p>\n\n<p>If you really want to considerably reduce amount of blue light coming from your monitor, I recommend changing white backgrounds to yellow ones (if you work with lots of white backgrounds). This will drastically cut blue light reaching your eyes in a way not possible when still retaining impression of whiteness. Of course, eliminating large, bright areas by using dark themes (white-on-black text) will greatly cut ALL light.</p>\n\n<p>If you seek to reduce strain on your eyes from monitor then I agree with statement that the biggest issue is not just the amount of light coming from the monitor. The biggest factor IMHO is the <strong>difference</strong> between monitor and it's background, that is the rest of the room. Therefore never use a computer/phone/tablet in total darkness - leave some nightlight + lower brightness to match. Also don't be afraid to crank up monitor up to 11 in a sunny day. Most monitors are set up to allow easy access to brightness and contrast adjustment - exactly for this very reason. They are meant to be used every time light in the room changes.</p>\n", "score": 17 }, { "answer_id": 9735, "body": "<p>I don't have any information about whether the Benq monitor in particular will effectively reduce blue light.</p>\n<p>But to your question... &quot;Is it helpful?&quot;</p>\n<p><a href=\"http://articles.mercola.com/sites/articles/archive/2016/10/23/near-infrared-led-lighting.aspx\" rel=\"nofollow noreferrer\">This article</a> is fairly well referenced, and includes an interview with Dr Wunsch, a German light therapist. In summary, it seems long exposure to blue light from artificial sources is indeed a bad for you in both the ways mentioned by Agent_L.</p>\n<p>The article mentions blue-blocking glasses as an alternative solution. Maybe give that a try - it'll be cheaper than a new monitor, and even the layman that Agent_L's mentions, would probably accept that blue light is reduced by wearing a filter over your eyes.</p>\n<p>UPDATE: a partially functional archive copy of this article is now <a href=\"https://archive.ph/wShBy\" rel=\"nofollow noreferrer\">here</a>.</p>\n", "score": 1 } ]

[ "eye", "computers", "vision", "benefits", "technology" ]

[ { "answer_id": 29256, "body": "<p>The most noteworthy complication, and most heard about in the news, is anaphylaxis.</p>\n<p>This article breaks down cases of anaphylaxis nicely: <a href=\"https://jamanetwork.com/journals/jama/fullarticle/2776557\" rel=\"nofollow noreferrer\">Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US—December 14, 2020-January 18, 2021</a>. They provide a great table with a specification of whether the case happened during the 15-minute window:</p>\n<p><a href=\"https://i.stack.imgur.com/lqLsL.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/lqLsL.png\" alt=\"enter image description here\" /></a></p>\n<p>So for Pfizer specifically the numbers are:</p>\n<ul>\n<li>4.7 anaphylaxis cases per million in total</li>\n<li>3.6 cases per million if only the 15 minute window is considered</li>\n<li>1.1 per million for those without a prior allergic reaction to a drug or vaccine</li>\n</ul>\n<p>This doesn't account for non-anaphylaxis allergic reactions (more common, less severe), vasovagal syncope(fear of needles/injections), or any other, more rare conditions.</p>\n<p>To date data regarding medical attention received within 15 minutes of vaccination has been hard to come by. The data from the first week of Pfizer administration, covering some 1.8m patients <a href=\"https://www.cdc.gov/mmwr/volumes/70/wr/mm7002e1.htm\" rel=\"nofollow noreferrer\">shows that non-anaphylaxis allergic reactions were roughly 8 times more common</a> (and typically far less severe) than anaphylactic reactions.</p>\n<p>While we could attempt to extrapolate based on anaphylaxis cases and non over the year based on the first week's data, it'd be a relatively pointless exercise. The occurrences/million for anaphylaxis dropped from 11.1 to 4.7 in the time frame. We can't assume the reduction in case numbers to be proportionally identical, yet a simple extrapolation based only on time would be disingenuous.</p>\n<p>In short, reliable data on the topic outside anaphylaxis is hard to come by because other instances requiring medical attention are either less severe or less common.</p>\n", "score": 17 }, { "answer_id": 29254, "body": "<p>The data on this aren't hard to find. Here are some more examples that specifically provide time frames to back up @A Rogue Ant's answer:</p>\n<p>For the <a href=\"https://www.cdc.gov/mmwr/volumes/70/wr/mm7002e1.htm\" rel=\"noreferrer\">Pfizer vaccine</a>:</p>\n<blockquote>\n<p>During December 14–23, 2020, monitoring by the Vaccine Adverse Event\nReporting System detected 21 cases of anaphylaxis after administration\nof a reported 1,893,360 first doses of the Pfizer-BioNTech COVID-19\nvaccine (11.1 cases per million doses); <strong>71% of these occurred within\n15 minutes of vaccination</strong>.</p>\n</blockquote>\n<p>And for <a href=\"https://www.cdc.gov/mmwr/volumes/70/wr/mm7004e1.htm\" rel=\"noreferrer\">Moderna</a>:</p>\n<blockquote>\n<p>During December 21, 2020–January 10, 2021, monitoring by the Vaccine\nAdverse Event Reporting System detected 10 cases of anaphylaxis after\nadministration of a reported 4,041,396 first doses of Moderna COVID-19\nvaccine (2.5 cases per million doses administered). <strong>In nine cases,\nonset occurred within 15 minutes of vaccination.</strong> No\nanaphylaxis-related deaths were reported.</p>\n</blockquote>\n<p>In both studies, 70-90% of anaphylactic reactions occurred within the first 15 minutes, hence the 15-minute protocol.</p>\n", "score": 13 }, { "answer_id": 29253, "body": "<p><strong>For the UK up to 27 October 2021:</strong></p>\n<p>All recipients were requested to wait 15 minutes before departing the point of vaccination.</p>\n<p>A history of anaphylactic reactions to any of the ingredients forbids taking the vaccine, but which dose (first or second) the listed reactions occurred after is not specified in the data.</p>\n<p>Estimated first/second doses - Vaccine Manufacturer - Anaphylaxis or anaphylactoid reactions.</p>\n<blockquote>\n<p>23.5/20.3 million doses - Pfizer/BioNTech vaccine - 517</p>\n</blockquote>\n<blockquote>\n<p>24.9/24.1 million doses - AstraZeneca - 834</p>\n</blockquote>\n<blockquote>\n<p>1.5/1.3 million doses - Moderna - 41</p>\n</blockquote>\n<p>From <a href=\"https://www.gov.uk/government/publications/coronavirus-covid-19-vaccine-adverse-reactions/coronavirus-vaccine-summary-of-yellow-card-reporting\" rel=\"noreferrer\">UK Government website</a> 8th November 2021.</p>\n<p><strong>With reference to the total number of reactions reported:</strong></p>\n<p><a href=\"https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1031316/Pfizer_CORRECT.pdf\" rel=\"noreferrer\">Pfizer/BioNTech</a> - 357,084 (Anaphylactic data on page 31)</p>\n<p><a href=\"https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1031317/AZ_CORRECT.pdf\" rel=\"noreferrer\">Astra Zenica</a> - 836,957 (Anaphyl. data page 37)</p>\n<p><a href=\"https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1031318/Moderna.pdf\" rel=\"noreferrer\">Moderna</a> - 55,081 (Anaphyl. data page 18)</p>\n<p>A small number of reports from <a href=\"https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1031319/Unspecified.pdf\" rel=\"noreferrer\">unspecified vaccines</a> with 1 anaphylactoid reaction for 3,557 reports.</p>\n", "score": 5 } ]

[ "vaccination", "covid" ]

[ { "answer_id": 288, "body": "<p>You're going to want to read the label from top to bottom.</p>\n<h3>Serving Size and Calories</h3>\n<p>The first thing you will see at the top tells you the serving size and the amount of calories. It will say &quot;Serving Size {x} &quot; where x is the amount of whatever measurement is used. It may also give the amount of another measurement (usually grams) and sometimes even amount of how many of the product is one serving size (chip bags usually do this). Using the amount of servings that you eat, you can use simple math to determine how much of each nutrient/vitamin you have, this also includes the daily value percentage.</p>\n<p>Under the serving size, there will be the amount of calories and the amount of calories from fat. The calories shown are the calories per serving, so if you eat two servings, then you can double the amount of calories. You can compare the calories that you eat to the daily amount you are supposed to have.</p>\n<p>General rules for calories (based on a 2000 calorie diet)</p>\n<ul>\n<li>40 calories or less - low</li>\n<li>Around 100 calories - moderate</li>\n<li>400 calories or more - high</li>\n</ul>\n<p>Calories from fat are just the amount of calories that come from fat in the product. Calories are important because eating too many calories is linked to obesity.</p>\n<h3>Nutrients</h3>\n<p>The next section (under calories) on the food label is about the nutrients in the food. There are two subsections in this section, nutrients to limit and nutrients to get enough of.</p>\n<p><strong>Nutrients to Limit</strong></p>\n<ul>\n<li>Total Fat - under it there will also be trans and saturated fat</li>\n<li>Cholesterol</li>\n<li>Sodium</li>\n</ul>\n<p>These nutrients have been shown to increased risks some cancers, heart disease, and high blood pressure.</p>\n<p><strong>Nutrients to get Enough of</strong></p>\n<ul>\n<li>Dietary Fiber - under Total Carbohydrates</li>\n<li>Vitamins A and C</li>\n<li>Calcium</li>\n<li>Iron</li>\n</ul>\n<p>Getting more of these has been shown to reduce the risk of many of the diseases and problems mentioned, but you shouldn't have too many of these.</p>\n<p><strong>Other nutrients</strong></p>\n<ul>\n<li>Total Carbohydrates - sugar is under this</li>\n<li>Protein</li>\n</ul>\n<p>These foods are neutral-ish, but there are some risks in having too much (over the limit) of these. In fact, too much sugar has been shown to increase the risk of diabetes.¹</p>\n<p><strong>Reading the numbers</strong></p>\n<p>The nutrients to limit usually have both an actual amount and a daily value percentage (%DV) based on a 2000 calories diet. The nutrient to get enough of usually don't.</p>\n<p>Guide to %DV</p>\n<ul>\n<li>5% or less - low</li>\n<li>20% or more - high; most products won't have anything higher than 20%</li>\n</ul>\n<p>If you have something that has 20%DV of vitamin A, then there will 80%DV of vitamin A left. You could eat 4 more products with 20%DV of vitamin A or some other combination that equals 80%DV.</p>\n<h3>Footnote</h3>\n<p>There will three columns, one with the daily recommended amount for a 2000 calories diet and one for a 2500 calorie diet. All of the %DV are based on the 2000 calorie diet, but you can easily convert the percentages to the 2500 calorie diet if you have a calculator (or you can do them by hand). The one column I didn't mention is the calories column. If it says &quot;Less than&quot; then you should have less than the amount said in the column of the diet you are on.</p>\n<p>Usually &quot;Total Fat&quot;, &quot;Sat Fat&quot;, &quot;Cholesterol&quot;, and &quot;Sodium&quot; will have a &quot;Less than&quot; next to them, so you should have less of these than the amount to the right says. &quot;Total Carbohydrates&quot; and under it &quot;Dietary Fiber&quot; will usually have nothing next to them, so you should get the recommended value to the right.</p>\n<hr />\n<h3>Reading an ingredient list</h3>\n<p>This is a bit trickier than reading the actual label, but the ingredients should be put in order of quantity. There isn't any definite way to see the exact amount of each ingredient in the product, though. It is better to rely on the amount of each nutrient instead of trying to guess how much of each ingredient there is. If you just want to know what you are eating, then there are some good tricks.</p>\n<ul>\n<li>Sugar has many names - high-fructose corn syrup or corn syrup, agave nectar, barley malt syrup, dehydrated cane juice</li>\n<li>Sodium does too - salt, sodium benzoate, disodium, monosodium glutamate</li>\n<li>Trans fat - not listed as an ingredient, but it is in hydrogenated oil which is a common ingredient</li>\n</ul>\n<hr />\n<p>^{[1] <a href=\"https://health.stackexchange.com/a/60/26\">Is there evidence that eating too much sugar can increase the risk of diabetes?</a>}</p>\n<p>^{<a href=\"http://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm274593.htm\" rel=\"noreferrer\">How to Understand and Use the Nutrition Facts Label</a>}</p>\n<p>^{<a href=\"http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Understanding-Ingredients-on-Food-Labels_UCM_433234_Article.jsp\" rel=\"noreferrer\">Understanding Ingredients on Food Labels</a>}</p>\n", "score": 14 } ]

[ "nutrition", "labeling" ]

[ { "answer_id": 1142, "body": "<p>The simpler story is that it is better to eat whole fruit. </p>\n\n<p>The problem with eating smoothies or even drinking fruit juice is that you are increasing the fruit's glycaemic index. For example, an orange has a glycaemic index of 40, while orange juice has a glycaemic index of 50¹. The theory goes that low glycaemic index foods lower the risk of metabolic disorders such as obesity and diabetes and there is indeed epidemiological data which confirms this specifically about fruit and fruit juice: </p>\n\n<blockquote>\n <p>Greater consumption of specific whole fruits, particularly blueberries, grapes, and apples, is significantly associated with a lower risk of type 2 diabetes, whereas greater consumption of fruit juice is associated with a higher risk. </p>\n</blockquote>\n\n<p>based on data from 3 studies which followed a total of ~150 000 women and ~35 000 men for 18 to 24 years.². Note that the consumption of fruit juice increases the diabetes risk when compared to baseline, not just when compared to whole fruit. </p>\n\n<p>Seeing that the average person in a Western culture has a higher chance of developing a metabolic disorder than of having difficulties digesting cellulose, we can conclude that, ceteris paribus, fruit is healthier for you than fruit juice. I did not find data on smoothies and purees, they should fall between whole fruit and fruit juice in glycaemic index. </p>\n\n<p>The story gets murkier when we consider your diet as a whole. People are unlikely to eat a whole orange when they are thirsty. So if you are currently drinking orange juice and planning to switch to the same amount of whole oranges and switch to drinking water, this is probably going to be a healthy decision. But if you are going to switch to drinking Coca cola when thirsty, it will likely be worse. While I did not look for data doing this comparison, the glycaemic index of Coca cola is 63¹, and it also contributes many calories without them being paired with micronutrients. </p>\n\n<p>There has been some debate on whether recommending diets based on GI makes sense, see these two 2002 reviews (paywalled): ³ and ⁴. Anecdotally, I'd say that they make sense, as I have seen people lose weight on them without complaining of hunger pangs. </p>\n\n<hr>\n\n<p>¹ <a href=\"http://www.health.harvard.edu/healthy-eating/glycemic_index_and_glycemic_load_for_100_foods\">http://www.health.harvard.edu/healthy-eating/glycemic_index_and_glycemic_load_for_100_foods</a></p>\n\n<p>² <a href=\"http://dx.doi.org/10.1136/bmj.f5001\">http://dx.doi.org/10.1136/bmj.f5001</a></p>\n\n<p>³ <a href=\"http://dx.doi.org/10.1046/j.1467-789X.2002.00079.x\">http://dx.doi.org/10.1046/j.1467-789X.2002.00079.x</a></p>\n\n<p>⁴ <a href=\"http://dx.doi.org/10.1046/j.1467-789X.2002.00080.x\">http://dx.doi.org/10.1046/j.1467-789X.2002.00080.x</a></p>\n", "score": 12 }, { "answer_id": 1454, "body": "<p>There is a simpler answer than others on this page.</p>\n\n<p>Drinking the calories associated with 4 oranges can be done in about 5 seconds. This does not give your body's satiety mechanisms time to kick in and diminish your appetite if you are already tanked up on the calories you need for that day.</p>\n\n<p>By contrast, eating the fruit (with peeling-time thrown in) is much slower, and gives your satiety mechanisms a chance to tell you that you don't really need the calories in that 4th orange.</p>\n\n<p>The biggest nutritional danger today is not scurvy or any other vitamin deficiency. It's over-nutrition, i.e. too many calories. By eating the oranges, vs. drinking then, you reduce the danger of over-nutrition. Dr. Daniel Lustwig's editorial in JAMA first opened my eyes to this aspect of juice drinks.</p>\n", "score": 7 } ]

[ "nutrition", "fruits" ]

[ { "answer_id": 1479, "body": "<p>Well regular sleeping during the day might damage health. Try avoiding it if possible as research has been conducted which suggests that there is a linkage between irregular sleep and hormone production.</p>\n\n<p>Evidence also suggests that lack of sleep won't do you as much damage as irregular or day sleep. I suggest try changing your profession. If that isn't possible due to personal or social reasons then I'd say try adjusting your shift so you can sleep at night.</p>\n\n<p>Erratic sleep is bad no matter what. While you might be able to reduce the effects bit napping at night, it won't make much difference.</p>\n\n<p>You have Vitamin D deficiency because of lack of exposure to sunlight and pills and taking walk in the sunlight can fix that easily.</p>\n\n<p>Growth Hormone deficiency does as a matter of fact effect your sleeping pattern and vice versa. I don't know your age neither am I a doctor but assuming you are young enough, this can be fixed by medical help and change in habits.</p>\n\n<blockquote>\n <p>...shifted sleep appears to disrupt gene activity even more than not getting enough sleep, according to the research.</p>\n</blockquote>\n\n<p>In a study published in PNAS, 22 young, healthy subjects were tested in a sleep lab. Interrupting their sleep so that their longest period of sleep was from noon until about 6:30 p.m., they found</p>\n\n<blockquote>\n <p>On the days of shifted sleep... the number of genes tied to the body's clock dropped dramatically, to 228 genes, or only 1 percent of genes analyzed. ...The researchers estimated that the sleep disruptions would ultimately impact about a third of a person's genes.</p>\n</blockquote>\n\n<p>This is significantly more than found in studies done on sleep deprivation.</p>\n\n<blockquote>\n <p>\"We think that may be related to the negative health outcomes associated with long-term shift work,\" Dijk said. Shift workers are at higher risk for many health problems, including obesity, diabetes, high blood pressure, heart disease, disrupted menstrual cycles and cancer, he said.</p>\n</blockquote>\n\n<p>SOURCE: <a href=\"http://www.webmd.com/sleep-disorders/news/20140121/sleep-during-the-day-may-throw-genes-into-disarray\">WebMD</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21464567\">Growth hormone deficient children</a> have a significant decrease in total sleep time, efficiency, movement and in non-rapid eye movement sleep stage 2.</p>\n", "score": 7 }, { "answer_id": 1509, "body": "<p>Alright let's address some of those deficiencies!</p>\n\n<p>Vitamin-D: You produce this when you stand in the sun. Seriously.\nUnfortunately there isn't really good research about how long to go outside to get enough. Some sources suggest that 30 minutes twice a week is good enough. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17634462?dopt=Abstract\" rel=\"nofollow\">http://www.ncbi.nlm.nih.gov/pubmed/17634462?dopt=Abstract</a></p>\n\n<p>AST and the IGF growth factor tests mean that the doc is checking for liver and/or pituitary gland issues that could be affecting your growth or overall health. It's entirely possible that these are out of range and not indicative of a problem. Assuming that you are healthy aside from the Vit-D, we will only consider sleep.</p>\n\n<p>There is quite a bit of evidence for shift workers having increased rates of certain illnesses. Unfortunately, it is hard to say whether this is because of the actual timing of the work or because of the interruptions in sleep that tend to be more prevalent among people who sleep in this way.</p>\n\n<p><a href=\"http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.324.9801&amp;rep=rep1&amp;type=pdf\" rel=\"nofollow\">http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.324.9801&amp;rep=rep1&amp;type=pdf</a> </p>\n\n<p>Long story short, yes. Sleep can cause some illnesses. I can't find any references for growth hormone supression, but sleep disturbances can affect the endocrine system in other ways (like diabetes) that are fairly well documented. Now get off stack-exchange and go to bed. Oh, and go outside tomorrow and get your Vitamin D!</p>\n", "score": 4 } ]

[ "sleep", "endocrinology" ]

[ { "answer_id": 3154, "body": "<blockquote>\n <p>So my question is: Are smokers' lungs visibly and routinely blackened and/or discolored in the absence of lung disease?</p>\n</blockquote>\n\n<p>That last phrase is tricky, because smokers who have heavy pigmentation are likely to have lung disease.</p>\n\n<p>It is not a myth that smokers have black pigmentation in their lungs, but finding proof of gross pathology in picture form is difficult. </p>\n\n<p>Here is one slide from <a href=\"http://www.medicinenet.com/smokers_lung_pathology_photo_essay/page3.htm\" rel=\"noreferrer\">MedicineNet</a></p>\n\n<p><a href=\"https://i.stack.imgur.com/8HUqY.gif\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/8HUqY.gif\" alt=\"enter image description here\"></a></p>\n\n<p>This is gross (visible to the naked eye) pathology, and you can see dark pigmentation in the region of emphesematous blebs.</p>\n\n<p>What is <em>not</em> difficult to find are histopathology slides, and many of them show pigment-laden macrophages in smoker's lungs:</p>\n\n<p><a href=\"https://i.stack.imgur.com/subYm.gif\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/subYm.gif\" alt=\"enter image description here\"></a></p>\n\n<p>Although this was taken from the same page, this kind of slide is present in papers from many different authors.</p>\n\n<p><a href=\"https://i.stack.imgur.com/HA2mU.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/HA2mU.jpg\" alt=\"enter image description here\"></a> <a href=\"https://i.stack.imgur.com/fpOacm.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/fpOacm.jpg\" alt=\"enter image description here\"></a></p>\n\n<p>In an <a href=\"http://journals.lww.com/ajsp/Abstract/2002/05000/Respiratory_Bronchiolitis__A_Clinicopathologic.11.aspx\" rel=\"noreferrer\">American Journal of Surgical Pathology</a> on Respiratory Bronchiolitis, </p>\n\n<blockquote>\n <p>A correlation was found between degree of <em>cytoplasmic pigmentation of macrophages</em> and number of pack-years smoked and also between the presence of peribronchiolar fibrosis and number of pack-years. No correlation was found between pulmonary function test results and pathologic findings. ...Five cases of variant [Respiratory Bronchiolitis] were encountered that resembled RB except that macrophage cytoplasm lacked pigment. All occurred in never-smokers, and their significance is unknown.</p>\n</blockquote>\n\n<p>And again in <a href=\"http://www.mayoclinicproceedings.org/article/S0025-6196%2812%2965379-8/abstract\" rel=\"noreferrer\">another paper</a> on RB in <em>young</em> smokers,</p>\n\n<blockquote>\n <p>Respiratory bronchiolitis is a mild inflammatory reaction commonly noted in asymptomatic cigarette smokers. We reviewed 18 cases of respiratory bronchiolitis-associated interstitial lung disease (RB/ILD), which had been diagnosed on the basis of clinical evaluation and open-lung biopsy. All patients were cigarette smokers. The sex distribution of the patients was approximately equal, and their mean age was <em>36 years</em>. Chest roentgenograms showed reticular or reticulonodular infiltrates in 72% of the patients. <em>Histologically, inflammation of the respiratory bronchioles, filling of the bronchiolar lumens and surrounding alveoli with finely pigmented macrophages...</em></p>\n</blockquote>\n\n<p>Finally, I spoke with two county coroner employed pathologists who stated without hesitation that heavy pigmentation was present grossly in heavy smokers, and that without knowing if a person was a smoker or non-smoker, they were able to predict with accuracy who was a heavy smoker. Furthermore, I was invited to come take pictures of lungs on autopsy (going through the proper channels and with the families' permission) of smokers and nonsmokers to authenticate the difference (That won't help with the bounty, of course).</p>\n\n<p>Given all this, I don't believe that there is a medical conspiracy about smokers' lungs looking the way they do.</p>\n", "score": 30 } ]

[ "smoking", "lungs", "disease" ]

[ { "answer_id": 4010, "body": "<p>There have been quite a few studies on the influence of meal frequency, but usually they focus on weight loss.</p>\n\n<p>I could find one pilot study comparing people receiving either one or three meals a day, for a total of 8 weeks, while receiving the same amount of calories in total. All study subjects maintained their body weight. The study concluded:</p>\n\n<blockquote>\n <p>There were no significant effects of meal frequency on heart rate, body temperature, or most of the blood variables measured. However, when consuming 1 meal/d, subjects had a significant increase in hunger; a significant modification of body composition, including reductions in fat mass; significant increases in blood pressure and in total, LDL-, and HDL-cholesterol concentrations; and a significant decrease in concentrations of cortisol</p>\n</blockquote>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2645638/\">A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults</a></p>\n\n<p>Note, however, that over a quarter of study subjects withdrew during the study. The authors report that it was for unrelated reasons, but such a high drop out rate is still a cause for concern. A concern you voice in your question is hunger, and when eating only one meal a day, that was something the study subjects reported significantly more than when eating three meals a day. </p>\n\n<p>As I said, most studies focus on weight loss,and most have few study subjects. A recent meta-analysis (analyzing the existent literature on the topic) found </p>\n\n<blockquote>\n <p>Three randomized controlled clinical trials of fasting in humans were identified, and the results were published in 5 articles, all of which evaluated the effects of fasting on surrogate outcomes. Improvements in weight and other risk-related outcomes were found in the 3 trials. Two observational clinical outcomes studies in humans were found in which fasting was associated with a lower prevalence of CAD or diabetes diagnosis. No randomized controlled trials of fasting for clinical outcomes were identified</p>\n</blockquote>\n\n<p>But ultimatively concluded:</p>\n\n<blockquote>\n <p>Whereas the few randomized controlled trials and observational clinical outcomes studies support the existence of a health benefit from fasting, substantial further research in humans is needed before the use of fasting as a health intervention can be recommended.</p>\n</blockquote>\n\n<p><a href=\"http://ajcn.nutrition.org/content/102/2/464.abstract\">Health effects of intermittent fasting: hormesis or harm? A systematic review</a></p>\n\n<p>Intermittent fasting isn't exactly like what you are describing, but it comes close, and there's more studies on it than eating just one meal a day, which I suppose many people find unsustainable. </p>\n\n<p>As an example for what I mean when I say studies are usually small, one that I saw cited a lot is: <a href=\"http://ajcn.nutrition.org/content/90/5/1244.full\">Intermittent fasting does not affect whole-body glucose, lipid, or protein metabolism</a>. That study bases its conclusion, that Intermittent Fasting doesn't affect insulin sensitivity and various other factors on a study in just 8 healthy, lean males. </p>\n\n<p>Overall, I don't think there's a recommendation based on evidence that can be given - no frequency of meals that we can point to and say \"this is the optimal frequency for being healthy\". Or, at the very least, there isn't one yet (personally, I doubt there ever will be). No meal frequency seems to be associated with dramatic negative effects on health, and some may be associated with small beneficial changes. As it is, any meal frequency that person finds sustainable and satisfying is probably good. </p>\n", "score": 14 } ]

[ "nutrition", "calories" ]

[ { "answer_id": 22799, "body": "<p>The confusion exists because there are conflicting pronouncements from various authoritative sources but also conflicting pronouncements from the same authority.</p>\n\n<p>Covid-19 is a respiratory infection spread by droplets that can be aerosolized (nuclear droplets) in certain situations such as by flushing toilets or in certain medical procedures such as intubation. However, it reaches the air it contaminates surfaces and this allows for the infection to be caught through the eyes nose and mouth with the virus being transferred from the hand.</p>\n\n<p>The data from Singapore and Taiwan show that handwashing and social distancing are successful in preventing disease transmission. However, if social distancing is not rigorously enforced then you will need to wear a mask. The head of the Chinese CDC, Dr George Gao, has recommended that everyone wear a mask which is advice that contradicts most countries health ministries. This is so that the infected are not shedding as many viral particles into the environment. His advice is based on the fact that there is a high degree of asymptomatic infection in the community and these people are spreading the virus by droplets just by talking and exhaling. The contrary advice is because they feel users are wearing masks to protect themselves, and, in the absence of training, they are almost certainly less effective at providing protection. But trained users have a similar degree of protection with both surgical masks and N95 masks.</p>\n\n<p>So the main way of disease transmission is by respiratory droplet. But the fact that health workers, NYPD officers (currently over 500) and others are getting infected wearing masks points to surface contamination as the second main mode of infection, or, possibly lack of training in wearing the masks and/or poor hand washing, or, that aerosol transmission is indeed important.</p>\n\n<p><a href=\"https://www.sciencemag.org/news/2020/03/not-wearing-masks-protect-against-coronavirus-big-mistake-top-chinese-scientist-says#\" rel=\"nofollow noreferrer\">https://www.sciencemag.org/news/2020/03/not-wearing-masks-protect-against-coronavirus-big-mistake-top-chinese-scientist-says#</a></p>\n\n<p><a href=\"https://www.bostonglobe.com/2020/03/19/opinion/guidance-against-wearing-masks-coronavirus-is-wrong-you-should-cover-your-face/\" rel=\"nofollow noreferrer\">https://www.bostonglobe.com/2020/03/19/opinion/guidance-against-wearing-masks-coronavirus-is-wrong-you-should-cover-your-face/</a></p>\n", "score": 12 }, { "answer_id": 24307, "body": "<p>The main way COVID19 spreads (according to experts) is either <strong>droplets</strong> (short distance, &lt;6ft. short duration, &lt;5 seconds from emission) OR <strong>aerosols</strong> (long distance, 20ft+, whole room. long duration, &gt;60minutes)</p>\n<p>Unfortunately, as of July 2020, we still don't know.</p>\n<p>WHO has updated their modes of transmission: <a href=\"https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions\" rel=\"nofollow noreferrer\">https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions</a></p>\n<p>July 9.</p>\n<p>They say there isn't hard evidence of for <code>H1: aerosol&gt;droplet</code>, so they are sticking to their null hypothesis <code>H0: droplet &gt; aerosol</code>. However, the detractors say there isn't hard evidence for <code>H0</code> either.</p>\n<p>After talking to several doctors and chemists and reading about 5-10 articles, my conclusion (i.e. educated guess) is that it's about a tie between droplets and aerosols.</p>\n<p>The key details can be found in the OPTIONAL section of this 10 minute science communication piece (<a href=\"http://tinyurl.com/covid3particles\" rel=\"nofollow noreferrer\">http://tinyurl.com/covid3particles</a>).</p>\n<h3>It's endogenous -- the main mode of transmission depends on what protective practices are in place.</h3>\n<ul>\n<li>If you 100% protect against droplets, then aerosols will probably be the main mode.</li>\n<li>If you use no protection, then droplets are probably the main mode.</li>\n<li>If you are never in someone else's room (except after airing it out), then fomites (surfaces) might be the main route. But only because you eliminated everything else.</li>\n</ul>\n<p>You can also look at the CHAIN model. (tinyurl.com/CHAINmodel) especially the end of the article.</p>\n<h3>Surfaces and soap are, unfortunately, not foolproof/complete protection.</h3>\n<p>There are many people who wash their hand religiously. They still can get sick. So, we know that perfect hand washing won't stop it.</p>\n<p>PS: Agree with @Graham's answer</p>\n", "score": 2 } ]

[ "covid-19", "infection", "virus", "epidemiology", "coronavirus" ]

[ { "answer_id": 94, "body": "<p>There are a few considerations when looking at a healthy lacto-ovo vegetarian diet.</p>\n\n<p><strong>Complete Proteins</strong></p>\n\n<p>This is fairly easy in this type of diet, as eggs contain complete proteins. There are also a few plant sources (such as quinoa, buckwheat and hempseed) that contain either a complete protein profile or the 9 essential amino acids in good amounts. Hempseed also contains Omega-3 fatty acids which can be difficult to get without seafood.</p>\n\n<p><strong>Healthy Fats</strong></p>\n\n<p>One of the main reasons for healthy fats in the diet is for the proper transport of fat soluble vitamins (A, D, E, and K) into the body. Nuts and avocados are examples of healthy fats, as are olives and olive oils. If possible, for olive oils get extra virgin and as fresh as possible, as this will ensure the highest levels of polyphenols.</p>\n\n<p>Along with the basic considerations, you need to be aware of possible deficiencies due to age, sex, things of this nature. For example, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15570032\" rel=\"noreferrer\">this study</a> suggests that B-12 deficiency can be a problem in pregnant lacto-ovo vegetarians. High soy intake can possibly impact estrogen levels in both men and women, and possibly delay maturation/height in maturing individuals, although this is only a precaution (most of what I've read suggests further studies are needed).</p>\n\n<p>I would talk with a nutritionist and/or doctor about the diet, and why you want to follow it. There's no reason you can't be healthy and safe about whatever diet plan you choose.</p>\n", "score": 16 }, { "answer_id": 123, "body": "<p>NOTE: this answer only focuses on proteins.</p>\n\n<h2>Short answer</h2>\n\n<p>With beans (beans, chickpeas, lentils, etc.) and cereals.</p>\n\n<h2>Long answer</h2>\n\n<p>There are proteins in many vegetable foods, the difference with meat is the percentage of protein. Here you have a table of protein content of most protein-rich plant foods, plus beef meat for comparison (values are g of protein per 100 g of uncooked product):</p>\n\n<ul>\n<li>beef meat 22</li>\n<li>beans 24</li>\n<li>chickpeas 21</li>\n<li>lentils 23</li>\n<li>wheat (bread, pasta, etc.) 10-13</li>\n<li>corn 10</li>\n<li>rice 6-8</li>\n</ul>\n\n<p>In a omnivore diet, meat is just one source of proteins among others, and provides just a part of total protein intake. It's perfectly possible to get enough proteins without meat. Actually our society is suffering from diseases that are caused by excess, not lack, of proteins [3,4].</p>\n\n<h2>Essential amino acids</h2>\n\n<p>Every protein we eat through the diet is made of amino acids. There are some amino acids we need to eat in order to satisfy our requirements, these are called <em>essential amino acids</em>. </p>\n\n<p>While meat contains all essential amino acids, common vegetable foods -individually- lack some essential amino acid. The essential amino acids that are not found in some vegetable foods can be found in other vegetable foods, for this reason it's important to eat variedly. If focusing on one type of bean, like soy, can lead to deficiencies, we avoid them by rotating the consumption of beans and cereals over the week. Some examples can be found on the web[<a href=\"http://www.bastyr.edu/news/health-tips/2011/09/what-are-complementary-proteins-and-how-do-we-get-them\" rel=\"noreferrer\">1</a>].</p>\n\n<h2>Vegan diets</h2>\n\n<p>What was said until now is also valid for vegan diets: diets that exclude any animal product as meat, fish, milk, dairy, eggs, honey.</p>\n\n<p>With diets based on vegetable foods it's perfectly possible to satisfy all nutritional needs '<em>during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes</em>', as stated by the American Dietetic Association in 2009[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19562864\" rel=\"noreferrer\">2</a>]. You just have to eat enough beans, cereals and vegetables (they contain proteins too).</p>\n\n<h2>References</h2>\n\n<p>[3] Report of a Joint WHO / FAO Expert Consultation. (2003). Diet, nutrition and the prevention of chronic diseases. World Health Organization technical report series (Vol. 916). doi:ISBN 92 4 120916 X ISSN 0512-3054 (NLM classification: QU 145)</p>\n\n<p>[4] World Cancer Research Fund, &amp; American Institute for Cancer Research. (2007). Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Cancer Research.</p>\n", "score": 11 }, { "answer_id": 92, "body": "<p>Meat mostly provides you with protein and fat, so you'll have to make up for this. This will be easier for an ovo-lacto vegetarian.</p>\n<h3>Sources of fat</h3>\n<p>Nuts, nut butters (peanut butter, almond butter, etc.), oils, avocados</p>\n<h3>Sources of protein</h3>\n<p>Nuts, nut butters, eggs, dairy, soy foods (tofu, soy milk)</p>\n<h3>Vitamin B12</h3>\n<p>Cow milk, soy milk, eggs, fortified cereals (Multi-Grain Cheerios, Corn Flakes, Special K)</p>\n<hr />\n<p>^{<a href=\"http://youngwomenshealth.org/2013/12/05/vegetarian-diet/\" rel=\"nofollow noreferrer\">How to Be a Healthy Vegetarian</a>}</p>\n", "score": 9 }, { "answer_id": 1381, "body": "<p>In addition to including nutrients in your diet, you can consider natural supplements in your diet as well. </p>\n\n<p>This is because these days fruits and veggies are not as pure as they used to be, due to usage of fertilizers, insecticides etc. To get right nutrition, one option is to eat organic products but then they can be expensive. That's why I do not find harm in taking natural supplements. One such supplement is <strong>spirulina</strong> (which @JohnP mentioned as well). Spirulina is considered as super food and is shown to have a lot of health benefits:</p>\n\n<p><a href=\"http://www.livescience.com/48853-spirulina-supplement-facts.html\" rel=\"nofollow\">http://www.livescience.com/48853-spirulina-supplement-facts.html</a></p>\n\n<p><a href=\"http://articles.mercola.com/sites/articles/archive/2014/09/29/spirulina-benefits.aspx\" rel=\"nofollow\">http://articles.mercola.com/sites/articles/archive/2014/09/29/spirulina-benefits.aspx</a></p>\n", "score": 0 } ]

[ "nutrition", "diet", "vegetarianism" ]

[ { "answer_id": 526, "body": "<p><strong>tl;dr</strong></p>\n\n<p>Current research seems to indicate that the brain is responding to anticipation or visual stimulus of needles being inserted, not that any of the theories supporting acupuncture are correct.</p>\n\n<hr>\n\n<p>Steven Novella <a href=\"http://theness.com/neurologicablog/index.php/phantom-acupuncture/\">reviewed the following article</a>:</p>\n\n<p>Chae Y, Lee IS, Jung WM, Park K, Park HJ, Wallraven C. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25681621\">Psychophysical and neurophysiological responses to acupuncture stimulation to incorporated rubber hand.</a> Neurosci Lett. 2015 Feb 11;591C:48-52. doi: 10.1016/j.neulet.2015.02.025. </p>\n\n<p>I'm going to quote from Novella's review because it's easier for a lay person to read/understand, and I don't have full access to the paper.</p>\n\n<p>As background, he states:</p>\n\n<blockquote>\n <p>There have been in total several thousand clinical studies looking at the apparent effects of acupuncture. These have failed to convincingly reject the null hypothesis, meaning that they have not demonstrated a clear biological response to acupuncture for any indication. The better controlled studies consistently show that needle location does not matter (sham acupuncture), and that needle insertion does not matter (placebo acupuncture). You can literally have a non-acupuncturist randomly poke someone with toothpicks and get the same response as the full acupuncture treatment.</p>\n</blockquote>\n\n<p>And described the current paper:</p>\n\n<blockquote>\n <p>A recent study looked at performing acupuncture on a phantom limb.\n They used a now well-established technique of tricking the brain into\n incorporating a dummy body part as if it were real. They placed\n subjects in front of a table so that one of their arms was below the\n table, with a rubber arm above the table placed in such a way that\n visually the rubber arm looked like their own arm. They then stroke\n the rubber arm and the subjects real arm simultaneously. The brain\n sees and feels the rubber arm being stroked, and this sensory feedback\n is often enough for the brain to create the sensation of ownership\n over the rubber arm.</p>\n \n <p>The researchers then placed acupuncture needles into the rubber arm\n that subjects had incorporated as their own. Obviously there is no\n possibility of any physiological response from the needle penetrating\n the rubber arm. I further think it is reasonable to conclude that\n placing a needle into a rubber arm cannot activate acupuncture points\n (if they existed) or alter Qi (if it existed). This experiment nicely\n eliminates local physiological responses and any Qi responses to the\n needles.</p>\n \n <p>The researchers performed functional MRI scanning (fMRI) on subjects\n while needles were placed in their phantom rubber limbs. Keep in mind\n that fMRI research involves collecting lots of data and aggregating\n it. So the researchers are not looking at brain reactions in real\n time, just the aggregate brain activity of many subjects over many\n trials. They then look for statistical associations in the activity.</p>\n \n <p>What they found was the same brain activation that previous studies\n have found with acupuncture of real limbs.</p>\n \n <blockquote>\n <p>When the rubber hand was fully incorporated with the real body,\n acupuncture stimulation to the rubber hand resulted in the experience\n of the DeQi sensation as well as brain activations in the dorsolateral\n prefrontal cortex (DLPFC), insula, secondary somatosensory cortex\n (SII), and medial temporal (MT) visual area. The insular activation\n was associated with the DeQi sensation from the rubber hand.</p>\n </blockquote>\n \n <p>If these results hold up, this implies that the brain is simply\n responding to the expectation and visualization of the needle\n penetration. Actual needle penetration is unnecessary. The most\n parsimonious interpretation of this data is that acupuncture is all in\n the mind. There is no need to hypothesize the existence of Qi,\n acupuncture points, or a specific physiological mechanism for\n acupuncture.</p>\n \n <p>There are plenty of studies that show that the perception of pain is\n easily manipulated by simple things such as distraction. Swearing,\n distorting body image, and crossing your arms while one of them is\n pricked will all reduce pain perception. Pain perception is closely\n tied to attention, and so simple distraction is effective. It’s no\n surprise, therefore, that the brain responds to phantom stimulation.</p>\n \n <p>At the very least this study demonstrates that all prior studies\n looking at fMRI responses to acupuncture needle insertion were likely\n simply showing a non-specific brain response to the expectation and/or\n visualization of needle insertion, without the need to invoke any\n specific physiological responses.</p>\n</blockquote>\n", "score": 15 }, { "answer_id": 632, "body": "<p>Acupuncture is often used to treat pain conditions such as headache, lower back and osteoarthritis. It is based on scientific evidence that treatment can stimulate nerves under the skin and in muscle tissue and as result body is producing pain-relieving substances (such as endorphins)^{<a href=\"http://www.nhs.uk/conditions/acupuncture/pages/introduction.aspx\" rel=\"nofollow\">NHS</a>}.</p>\n\n<p>NICE recommends acupuncture only as a treatment option for chronic lower back pain, chronic tension-type headaches and migraines which are based on the scientific evidence.</p>\n\n<p>However more research is needed to established whatever acupuncture should be used for other pain remedies.</p>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/Conditions/Acupuncture/Pages/Evidence.aspx\" rel=\"nofollow\">Acupuncture - Evidence at NHS</a>}</p>\n\n<p>Read more about evidence at: <a href=\"https://www.evidence.nhs.uk/Search?q=acupuncture+pain\" rel=\"nofollow\">Evidence Search at NICE</a> and <a href=\"http://www.cochranelibrary.com/\" rel=\"nofollow\">Cochrane Library</a>.</p>\n", "score": 3 } ]

[ "pain", "treatment-options", "effectiveness", "placebo", "acupuncture" ]

[ { "answer_id": 504, "body": "<p>With respect to your peer-reviewed journal article, <em>Frontiers</em> isn't a particularly well-regarded journal series.</p>\n\n<p>AIDS denialism is alive and well, but there's a massive body of evidence pointing to HIV infection as the cause of AIDS. Just as a starting point, consider this 2010 report from the <a href=\"http://www.niaid.nih.gov/topics/HIVAIDS/Understanding/howHIVCausesAIDS/Pages/HIVcausesAIDS.aspx\" rel=\"nofollow\">NIH</a>.</p>\n\n<p>One should also consider what would be required for this widely accepted theory to be wrong <em>and</em> for that to remain hidden. I can tell you as an epidemiologist that, if I actually <em>had</em> solid evidence that there was a different causal mechanism for AIDS, that would do fascinating things for my career. To suppress something like that would not only require massive fraud, but massive fraud contrary to the incentives of the academic community.</p>\n", "score": 20 }, { "answer_id": 513, "body": "<p>To turn this question on its head, I'd like to propose a different question that the AIDS deniers haven't answered.</p>\n\n<p>If HIV were not the cause of AIDS, why would <em>anti-retroviral therapy</em> be so successful in preventing the disease? Each of the meds in the cocktails that stave off AIDS limit the ability of the virus - the HIV virus - to reproduce.</p>\n\n<p>It can be argued that AZT is effective against more viruses than HIV alone. Reverse Transcriptase (necessary for viral replication) is an enzyme necessary to the replication of many viruses. However, the AIDS denialists claim:</p>\n\n<blockquote>\n <p>...because the drugs are anti-viral and <em>anti-bacterial in nature</em>, they give a false impression of being effective for treating HIV infection. What appears a miraculous recovery in many patients is, in fact, the drugs’ effects upon the opportunistic infectious agents the person may harbor at the time, other than HIV. (from your source)</p>\n</blockquote>\n\n<p>AZT is not an antibactial. Antibiotics (as well as things not to be taken internally, e.g. bleach) are antibacterials. Antibiotics treat <em>Pneumocystis jiroveci</em> (formerly known as <em>Pneumocystis carinii</em>) and other microbial infections; they are useless against the common cold and other viruses. </p>\n\n<p>Pneumocystis first came to attention as a cause of interstitial pneumonia in severely malnourished and premature infants during World War II in Central and Eastern Europe. Today, it is more common in immunosuppressed patients: </p>\n\n<blockquote>\n <p>Clinically significant Pneumocystis pneumonia is virtually never observed in immunocompetent adults. Indeed, documentation of Pneumocystis jirovecii\n in a patient without known underlying disease should prompt a careful search for occult immune suppression... trimethoprim–sulfamethoxazole [the <em>antibiotic</em> Bactrim] remains the most effective regimen for treating severe Pneumocystis pneumonia... Patients with previous Pneumocystis pneumonia should receive lifelong secondary prophylaxis, unless reconstitution of the immune system occurs. ...Ledergerber and colleagues analyzed episodes of recurrent Pneumocystis pneumonia in 325 HIV-infected patients after they had peripheral blood CD4 cell count greater than 200 cells/ml and found no cases of recurrent Pneumocystis during a follow-up period totaling 374 person-years. Prophylaxis should be reintroduced if the CD4+ count falls below 200 cells/ml.</p>\n</blockquote>\n\n<p>An antibiotic can treat P. pneumonia in HIV-infected patients, but cannot restore immunocompetency; only anti-retrovirals can.</p>\n\n<blockquote>\n <p>The standard treatment [of HIV] consists of a combination of at least three drugs (often called “highly active antiretroviral therapy” or HAART) that suppress HIV replication. Three drugs are used in order to reduce the likelihood of the virus developing resistance. </p>\n</blockquote>\n\n<p>On the near-miraculous effect of combined antiretroviral in the treatment of HIV, your paper observes:</p>\n\n<blockquote>\n <p>Because these drugs also attack non-infected cells, they can destroy the immune systems’ healthy T-cells, and even cause a collapse identical to AIDS. </p>\n</blockquote>\n\n<p>But they offer no evidence of such a claim. No drug is without potential side effects. Some antibiotics can cause aplastic anemia, a condition certain to result in an immunocompromised status. However combined antiretrovirals save lives, they do not <em>cause</em> AIDS.</p>\n\n<p>The paper is full of similar holes.</p>\n\n<p>Deniers gain footholds by building straw men and knocking them down, not by advancing credible science.</p>\n\n<p>Untreated, HIV causes AIDS. Anti-retrovirals prevent it's development. </p>\n\n<p>_{<a href=\"http://www.thoracic.org/statements/resources/tb-opi/treatment-of-fungal-infections-in-adult-pulmonary-critical-care-and-sleep-medicine.pdf\">An Official American Thoracic Society Statement: Treatment of Fungal Infections in Adult Pulmonary and Critical Care Patients (2010)</a>}<br>\n_{<a href=\"http://www.who.int/topics/antiretroviral_therapy/en/\">World Health Organization</a>}<br>\n_{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/2081238\">White swans, black ravens, and lame ducks: necessary and sufficient causes in epidemiology</a>}<br>\n_{<a href=\"http://en.wikipedia.org/wiki/Inventing_the_AIDS_Virus\">Inventing the AIDS virus</a>} </p>\n", "score": 20 } ]

[ "virus", "pathophysiology" ]

[ { "answer_id": 4284, "body": "<p>The exact value depends on a lot of things - skin tone, the time of day, latitude, how deep the shade is,... </p>\n\n<p>The study <a href=\"http://www.sciencedirect.com/science/article/pii/S0960076005002220\">Vitamin D effective ultraviolet wavelengths due to scattering in shade</a> found that the UVB radiation at 280–320 nanometers that is needed for vitamin D production dropped to levels at around 50% in a tree shade and under an umbrella. It was much less on a covered veranda - around 11% - and completely absent in a car with closed windows.</p>\n\n<p><a href=\"http://www.bioone.org/doi/10.1667/RR1951.1?url_ver=Z39.88-2003&amp;rfr_id=ori%3Arid%3Acrossref.org&amp;rfr_dat=cr_pub%3Dpubmed&amp;\">Latitudinal Variations over Australia of the Solar UV-Radiation Exposures for Vitamin D₃ in Shade Compared to Full Sun</a> came to similar conclusions (emphasis mine):</p>\n\n<blockquote>\n <p>Using shade for UV_D3 exposures can reduce total UV-radiation exposure by <strong>37% to 58%</strong> compared to full sun UV_D3 exposures. This research indicates that an improved approach to optimize UV-radiation exposures for the production of vitamin D₃ is to use diffuse UV radiation under shade in and around the middle of the day.</p>\n</blockquote>\n\n<p>Since exposure to these wavelengths is what drives vitamin D production, an approximate answer to your question is probably \"around 35 to 55%\". </p>\n", "score": 10 }, { "answer_id": 927, "body": "<p>About 1/4 - it varies with the reflectivity of the surface, and angle of the sun. Detailed study is at <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20199222\" rel=\"nofollow\">http://www.ncbi.nlm.nih.gov/pubmed/20199222</a></p>\n", "score": 6 } ]

[ "dermatology", "micronutrients", "vitamin-d", "uv-rays" ]

[ { "answer_id": 969, "body": "<p>There is some very good evidence that replacing a manual toothbrush with an electric toothbrush can help in reducing plaque and the risk of gingivitis. </p>\n\n<p>The Cochrane Oral Health Group published a review^{<a href=\"http://www.cochrane.org/CD002281/ORAL_poweredelectric-toothbrushes-compared-to-manual-toothbrushes-for-maintaining-oral-health\">1</a>} that summarized over 50 studies from 1964-2011. A majority of the studies tested the effects of a rotating oscillating electric toothbrush against a manual toothbrush. Overall, they found a 21% reduction in plaque and an 11% reduction in gingivitis. </p>\n\n<p>There are some things that weren't found by the studies that were reviewed, mainly what the long-term dental benefits of electric toothbrushes. Also, side effects were rarely reported, so there was no sufficient evidence of whether electric toothbrushes can be harmful to your teeth. </p>\n\n<p>A study done in 2008^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18672987\">2</a>} tested oscillating powered toothbrushes against manual toothbrushes over a 9 month period. It started with a 3 week period of oral care. Then some people brushed twice daily with either an oscillating powered toothbrush, a manual toothbrush, and a manual toothbrush and flood together. The powered toothbrush was able to keep the levels of plaque lower than the other two groups and also help prevent gingival bleeding. Another 2010 study^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21250772\">3</a>} also found very similar results in which the oscillating toothbrush help reduce plaque and prevent gum bleeding. From these studies and many others, we can see that oscillating toothbrushes are better for your teeth than manual toothbrushes.</p>\n\n<p>There is another type of electric toothbrush, sonic toothbrushes. They work by vibrating the brush head at sonic speeds. Though there are more studies done on oscillating toothbrushes, there have been a few done on the effectiveness of sonic toothbrushes. This 2015 study^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25793947\">4</a>} found that sonic toothbrushes were significantly better at reducing plaque than manual toothbrushes. An earlier study published in 2014^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24738786\">5</a>} also found that sonic toothbrushes were more effective at plaque removal. They also found that for a short time (1 week), the sonic toothbrushes were better at reducing the risk of gingival inflammation. After 3 weeks though, the amount of papillary bleeding (bleeding in some parts of the mouth) were the same between those who used sonic toothbrushes and manual toothbrushes. Overall though, it seems that sonic toothbrushes are also better for your oral health than manual toothbrushes.</p>\n\n<p>So we can see that both main types of electric toothbrushes are better than manual toothbrushes. But which is better, sonic toothbrushes or oscillating toothbrushes? In fact, a handful of studies has been done on this topic.</p>\n\n<p>A 2013 study^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24282870\">6</a>} tested the two types of powered toothbrushes. Both the sonic and the oscillating toothbrushes were able to significantly reduce plaque and risk of gingivitis, but the results showed the oscillating toothbrush performed better than the sonic toothbrush. Three 2014 studies^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25831599\">7</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122979\">8</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122976\">9</a>} agree with the conclusion that oscillating toothbrushes are better at reducing plaque and gingival bleeding than sonic toothbrushes. All of those studies were performed very similarly and had some of the same researchers between them. From these results, we can see that oscillating toothbrushes are superior to sonic toothbrushes.</p>\n\n<p>For both electric toothbrushes, we can see that risk of gingivitis and the amount of plaque on the teeth are reduced. You did ask more thing which I will answer more directly.</p>\n\n<blockquote>\n <p>Are there really any long-term benefits associated with electric toothbrushes?</p>\n</blockquote>\n\n<p>Well, from the trials I've mentioned, we can see that this is most likely the case. The longest trial I directly mentioned^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18672987\">2</a>} was 9 months long and it showed that 9 months of consistently using an electric toothbrush did help reduce plaque and gingival bleeding. Manual toothbrush can keep your teeth clean, but it takes more work than an electric toothbrush.</p>\n\n<p><strong>Why doesn't everyone use an electric toothbrush if they are proven to be better?</strong></p>\n\n<p>Well, there are a few things that come into play^{<a href=\"http://www.jeffersondentalclinics.com/blog/2014/04/30/manual-toothbrush-vs-electric-toothbrush-pros-and-cons-jefferson-dental-clinics/\">10</a>}. Even though electric toothbrushes are more effective at cleaning teeth and they don't take as much work as manual toothbrush, some people aren't willing to pay so much for a toothbrush. Some of the cheapest electric toothbrushes cost only $5, but the higher quality ones can go for over $100. You can get a five pack of manual toothbrushes for under $5. Another con of electric toothbrushes is that they are a hassle. They are bigger, and they require batteries or they have to be charged. Some people just don't want to deal with that. Lastly, electric toothbrushes can be easily broken. If you drop it, that might be it and you just lost $10. Now, electric toothbrushes are becoming more popular, but some of these cons are still holding people back.</p>\n\n<hr>\n\n<p>^{[<a href=\"http://www.cochrane.org/CD002281/ORAL_poweredelectric-toothbrushes-compared-to-manual-toothbrushes-for-maintaining-oral-health\">1</a>] <a href=\"http://www.cochrane.org/CD002281/ORAL_poweredelectric-toothbrushes-compared-to-manual-toothbrushes-for-maintaining-oral-health\">Powered/electric toothbrushes compared to manual toothbrushes for maintaining oral health</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18672987\">2</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18672987\">PComparison of the use of different modes of mechanical oral hygiene in prevention of plaque and gingivitis</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21250772\">3</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21250772\">Manual orthodontic vs. oscillating-rotating electric toothbrush in orthodontic patients: a randomised clinical trial</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25793947\">4</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25793947\">Is a new sonic toothbrush more effective in plaque removal than a manual toothbrush?</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24738786\">5</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24738786\">Toothbrush efficacy for plaque removal</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24282870\">6</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24282870\">A 12-week clinical comparison of an oscillating-rotating power brush versus a marketed sonic brush with self-adjusting technology in reducing plaque and gingivitis</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25831599\">7</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25831599\">A randomized clinical trial evaluating gingivitis and plaque reduction of an oscillating-rotating power brush with a new brush head with angled bristles versus a marketed sonic brush with self-adjusting technology</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122979\">8</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122979\">A randomized 12-week clinical comparison of an oscillating-rotating toothbrush to a new sonic brush in the reduction of gingivitis and plaque</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122976\">9</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25122976\">A six-week clinical evaluation of the plaque and gingivitis efficacy of an oscillating-rotating power toothbrush with a novel brush head utilizing angled CrissCross bristles versus a sonic toothbrush</a>}</p>\n\n<p>^{[<a href=\"http://www.jeffersondentalclinics.com/blog/2014/04/30/manual-toothbrush-vs-electric-toothbrush-pros-and-cons-jefferson-dental-clinics/\">10</a>] <a href=\"http://www.jeffersondentalclinics.com/blog/2014/04/30/manual-toothbrush-vs-electric-toothbrush-pros-and-cons-jefferson-dental-clinics/\">Manual Toothbrush VS Electric Toothbrush: Pros and Cons</a>}</p>\n", "score": 19 } ]

[ "benefits", "brushing-teeth", "toothbrush", "gingivitis", "brands" ]

[ { "answer_id": 5558, "body": "<p>In long term studies, the effects have been mixed but mild. </p>\n\n<p>In hemodialysis patients, after about six months - melatonin no longer seemed to have physiologic <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23432361\" rel=\"noreferrer\">effects</a> but could still be detected at elevated levels in salivary samples suggesting the body adapted to it. </p>\n\n<p>Long term (six months) melatonin in mice <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23350971\" rel=\"noreferrer\">improved spatial learning and memory</a> and also <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/24793376\" rel=\"noreferrer\">protected against aluminum toxicity</a> suggesting that neuronal or axonal growth is improved with supplementation. </p>\n\n<p>Swedish teenagers and children with ADHD have been placed on melatonin <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25995170\" rel=\"noreferrer\">for several years</a> without known adverse effects.</p>\n\n<p>Only <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26692007\" rel=\"noreferrer\">mild averse effects</a> have been found with long term use of melatonin in humans (dizziness, headache, nausea, sleepiness.) </p>\n", "score": 7 } ]

[ "sleep", "side-effects", "endocrinology", "lasting-effects-duration", "melatonin" ]

[ { "answer_id": 14311, "body": "<h2>You as an untrained bystander can do little to nothing.</h2>\n\n<p>Professionally trained paramedics could (as an example) pull the leg and thus remove tension between two bone membranes (<em><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826636/\" rel=\"noreferrer\">periostei</a></em>) and in a best case scenario alleviate all pain. The bone itself has hardly any nerve endings, it is only the periosteum that causes pain. This only works in a few cases. Other options include administration of pain killers. </p>\n\n<p>A few “guidelines” what to do when:</p>\n\n<ol>\n<li>If the patient is in pain, call an ambulance.</li>\n<li>If the patient can not walk/stand up, call an ambulance.</li>\n<li>If the fracture is open (ruptured skin / blood), call an ambulance.</li>\n<li>If the patient was or still is unconscious, call an ambulance, check for vital functions (breathing, airways).</li>\n<li>If the patient wants an ambulance, call the ambulance.</li>\n</ol>\n\n<p>Bottom line: To be on the safe side, call an ambulance.</p>\n\n<hr>\n\n<h2>What <em>can</em> you do?</h2>\n\n<p>During my very first first-help training, my trainer said something that stuck with me: “We humans have two fundamental fears: To die, and to die alone”. While it is sometimes impossible to save someone’s life, we can always, always be with them and comfort them. \nSo, never leave a patient alone unless there is absolute need, and if so, communicate clearly that you will return very shortly and e.g. just need to grab an AED.</p>\n\n<p>Secondly, being in pain is not very enjoyable, and having a large crowd of bystanders assemble around the patient doesn’t make it a bit better. Try to give them the decency of privacy. If you have already called the ambulance, get a few people to spread out, watch out for the ambulance and guide them to the patient. Hush the other ones away or give them tasks like looking for AEDs in nearby public buildings.</p>\n\n<p>Thirdly, lying immobilised, the patient gets cold quite quickly. Make sure to keep them warm. Jackets, <s>a camp fire</s>, or a <a href=\"https://az768999.vo.msecnd.net/images/products/38/lampa66964_635848435088676854/lampa66964_large_0.jpg\" rel=\"noreferrer\">rescue blanket</a> are always a good idea, even on mild summer days. (Pro Tip: A rescue blanket makes it quite clear to the ambulance drivers where and who the patient is, and it also protects the patient from the watchful eyes of bystanders. Such blankets are usually a part of every first-aid set in public buildings).</p>\n\n<p>Lastly, as a patient you are very dependent on the people around you. Because patients are usually sitting and leaning against a wall or lying on the ground (to prevent meaningful damage if they should collapse), their field of vision is very limited. Pain also distracts, so they are not highly aware of their surroundings. \nThis is why one must explain every action one takes to them, especially if it includes coming very near or touching the patient.</p>\n\n<h2>TL;DR</h2>\n\n<p>Here’s what you could do (order and items on the list depend on every case, don’t take this as a standard rule). Reiterating from above, always tell the patient what you’re doing.</p>\n\n<ol>\n<li>Check vital functions</li>\n<li>Call ambulance</li>\n<li>Check vital functions again</li>\n<li>Direct someone to get a first-aid set from a nearby public building. </li>\n<li>Send a few people as “beacons” for an ambulance, have them look out for it and guide its way upon arrival at the scene.</li>\n<li>If there’s still a large crowd, send a few people looking for AEDs¹</li>\n<li>Ensure warmth of patient.</li>\n<li>Distract the patient until arrival of ambulance. </li>\n</ol>\n\n<hr>\n\n<p>¹: It’s not likely that you will need a defibrillator, and I wouldn’t send for one as a standard procedure. However, it is always easier to send people looking for <em>something</em> than just hushing them away.</p>\n", "score": 24 }, { "answer_id": 14308, "body": "<p>So let's assume you're speaking of a large bone, like the arm (humerus, radius or ulna) or leg (femur, tibia or fibula), but not the skull, spine or pelvis.</p>\n\n<p>A good rule of thumb: the larger the bone, the more serious it is.</p>\n\n<p>A second rule: if the skin is broken (the bone is sticking out), it is serious.</p>\n\n<p>So, if you suspect a hand or foot fracture with no blood, you can take the person to an urgent care center or ER.</p>\n\n<p>If you suspect a leg or arm fracture, best to call EMTs.</p>\n\n<p>If you see blood, or the person is unconscious, call the EMTs.</p>\n", "score": 5 }, { "answer_id": 14326, "body": "<p><strong>It all depends on the bone that is (or might be) broken, and on the overall condition of the patient.</strong></p>\n\n<ul>\n<li>Call an ambulance for a fractured skull, vertebra or hip.</li>\n<li>Call an ambulance for open fractures (bone piercing through the skin).</li>\n<li>Call an ambulance if the patient is/has been unconscious or under shock.</li>\n<li>Call an ambulance if you are not sure whether you need one.</li>\n<li>Call an ambulance if the patient requests it.</li>\n</ul>\n\n<p>Do not move the patient any more than necessary. Especially, <strong>if you suspect a spinal injury (broken vertebra), absolutely avoid moving the patient unless strictly necessary to save their life</strong>. If you are unsure, call 911 (North America), 112 (Europe) or the local equivalent; they will instruct you what to do.</p>\n\n<p>Secure the accident site if necessary, stay with the patient. Give first aid for any additional conditions (if any), comfort them, make sure they remain conscious, get a blanket to keep them warm if necessary, help them look after their belongings, direct the ambulance to the patient.</p>\n\n<p>It may be OK to take the patient to a hospital on your own if all of the following are true:</p>\n\n<ul>\n<li>The broken bone is just a limb and not under stress while sitting (arm, shoulder, collarbone, foot, possibly tibia or fibula)</li>\n<li>No other complications are present</li>\n<li>The patient can move without additional pain</li>\n<li>The patient agrees</li>\n</ul>\n\n<p>Get the patient to the nearest hospital (urgent care should be sufficient for cases that don’t require an ambulance) or suitable physician. If necessary, they will refer the patient to wherever adequate care can be given. Ski areas often have a specialized doctor in most villages, or even a sports clinic; the same may be true for other areas where outdoor sports are common.</p>\n\n<p>From my own experience, most with ski accidents:</p>\n\n<ul>\n<li>Once a skier asked me to help her up because she couldn’t get up on her own. That turned out to be a bad decision, as it turned a partial femur head fracture into a full one. Lesson learned: if the patient cannot or will not get up on their own, tell them to stay put and get help.</li>\n<li>Another time I came to a site where someone had a knee injured. Her husband had already attempted to splint her knee with her ski poles and attempted to get her up. Same mistake as above, we ended up getting help.</li>\n<li>Yet another time, someone fell on her wrist. She was still OK to ski carefully and I accompanied her to the doctor, who then determined a radius fractured near the wrist.</li>\n</ul>\n\n<p>I know of several skiers who skied downhill with leg or vertebra fractures which were not discovered until they got to the doctor’s. Certainly not recommended if you suspect that kind of injury.</p>\n\n<p><strong>Last but not least: if you feel you might need this kind of knowledge, consider taking a first aid course.</strong></p>\n", "score": 4 }, { "answer_id": 14324, "body": "<p>If both legs are OK and there is no way they could have a spinal injury, you may well find it is quicker to get them to hospital in your car. Drive very slowly over bumps and around corners, do not accelerate fast and leave plenty of stopping distance for slow braking. This would be my preferred option for a minor injury to an arm, hand, shoulder or foot.</p>\n\n<p>In any other situation, call an ambulance and follow the phone operator's instructions to the letter. Do <strong><em>NOT</em></strong> try to be clever or show initiative about treating the casualty - you could easily make things worse! That said, be very clear about the situation and telling the operator exactly what happened and any change to the casualty's condition. For example, moving a casualty or removing a bike helmet could increase the damage from a spinal injury, so normally this is a job for the experts - but if the casualty has stopped breathing then the first priority is CPR, because they're guaranteed to die if you don't.</p>\n\n<p>TBH though, your questions suggest you're asking in the wrong place - not the wrong forum, but just generally by asking on the net. You won't learn anything useful here. Get yourself to a properly-run first aid course, learn what to do from people who actually know, and do some hands-on practise so that you can actually do it yourself.</p>\n", "score": 3 }, { "answer_id": 14322, "body": "<p>If you are untrained on this subject matter, the best practise is to do nothing about the fracture.* Even most certified first aiders are not trained to handle broken bones. </p>\n\n<p>*By nothing I don't literally mean nothing. I would assume that you have already called for ambulance. If he is in a dangerous location you can try to move him, but you will have move the area of the broken bone as little as possible. If he is unconscious and not breathing proceed to CPR, even if his rib cage is fractured. If he is in an awkward position you can try supporting him with things around you.(for example he could be lying on his side and supporting himself with his arms. Slide a bag for him to lie on.) If he is bleeding seriously carry out first aid. General idea is keep him alive until help arrives, other things can wait.</p>\n", "score": 2 }, { "answer_id": 14323, "body": "<p>From personal experience I can definitely attest that a person with a broken arm can indeed (under reasonable circumstances) hobble to a car and be driven to the hospital (not sure which department, presumably first aid initially).</p>\n\n<p>In my case I was the child with the broken arm and my mom drove met to the hospital.</p>\n\n<p>This way (even with safe driving) I was in the hospital slightly faster then in any other scenario, and we did not put unnecessary pressure on the medical system.</p>\n\n<p>Note that I was not in significant pain, and no blood/bone was coming out (just an arm at an odd angle).</p>\n", "score": 1 } ]

[ "first-aid", "emergency", "bone-fractures" ]

[ { "answer_id": 14356, "body": "<p>Drug molecules, even when stored safely inside a tablet\\capsule, inside a closed container, upon a high shelf (hopefully), are still exposed to the environment, and are thus exposed to all of the chemical processes and reactions that go about all around us (to name just a few - oxidation, hydrolysis, isomerization, polymerization, and more). Depending on the type of drug molecule and its functional groups, the molecule may undergo all kinds of chemical processes that may change its structure and\\or properties.</p>\n\n<p>Therefore, drugs (and foodstuffs, as mentioned in the comment above) degrade and decompose over time, and are thus given an expiration date to indicate that after a certain amount of time, the drug's manufacturer strongly recommends to avoid using the product.</p>\n\n<p>An important remark should follow: the expiration date refers to <strong>the entire pharmaceutical product</strong>, i.e. the formulation, and not just the active ingredient. It is absolutely possible that the active ingredient will remain stable for a long time, but some inactive ingredient (excipient) in the tablet\\capsule\\syrup will have undergone some decomposition that may render the product ineffective, or even worse, toxic.</p>\n\n<p>A quick Google search for \"drug decomposition\" or \"drug degradation\" yields many useful results for further reading. To name just a few:</p>\n\n<p><a href=\"http://www.pharmaceutical-journal.com/learning/learning-article/understanding-the-chemical-basis-of-drug-stability-and-degradation/11029512.article\" rel=\"noreferrer\">Understanding the chemical basis of drug stability and degradation</a></p>\n\n<p><a href=\"https://www.slideshare.net/ms_optimisstic/drug-degradation\" rel=\"noreferrer\">Drug degradation</a> (Slideshare presentation)</p>\n\n<p><a href=\"https://www.slideshare.net/saharishkhaliq/pharmaceutical-degradation\" rel=\"noreferrer\">Pharmaceutical degradation</a> (Slideshare presentation)</p>\n\n<p>And here's a non-scientific article addressing the issue from another angle: <a href=\"https://www.npr.org/sections/health-shots/2017/07/18/537257884/that-drug-expiration-date-may-be-more-myth-than-fact\" rel=\"noreferrer\">That Drug Expiration Date May Be More Myth Than Fact</a> (might be an interesting read for you as well)</p>\n", "score": 22 }, { "answer_id": 14364, "body": "<p>Beside <a href=\"https://health.stackexchange.com/a/14356/11994\">Don_S's</a> very detailed answer I want to point out a few other things:\nAt least in my country, drugs are not only synthetic chemical drugs. Drugs can also be biological or contain other non synthetic chemical substances.\nExamples are:</p>\n\n<ul>\n<li><a href=\"https://en.wikipedia.org/wiki/Filipendula_ulmaria#Herbal_and_pharmacological\" rel=\"nofollow noreferrer\">Early versions of what is now known as \"Aspirin\" was gained from the plant Meadowsweet.</a></li>\n<li><a href=\"https://en.wikipedia.org/wiki/Smallpox_vaccine\" rel=\"nofollow noreferrer\">Some preventive antivirus drugs contain weak forms of the real virus</a></li>\n<li><a href=\"https://en.wikipedia.org/wiki/Emulsion#Health_care\" rel=\"nofollow noreferrer\">Some of the drugs are or contain a mixture of oils and fats.</a> <a href=\"https://en.wikipedia.org/wiki/Emulsion#Instability\" rel=\"nofollow noreferrer\">They can go bad the same as for example butter after some time.</a> Some of them have such a short life time that they are directly produced on demand in the drug store and will expire after few days or weeks.</li>\n</ul>\n\n<p>It is hard to produce under such steril conditions and packaging that it is ensured that it will not get polluted for decades.</p>\n\n<p>Another reason might be that the storage life was tested/is known for a limited amount of time and cannot be guaranteed for a longer timespan.</p>\n", "score": 6 } ]

[ "expiration-dates" ]

[ { "answer_id": 26259, "body": "<p>The MSDS linked to is for a product sold as a solution of 10% SM-102 in 90% chloroform. It's listed as &quot;SM-102&quot; because that's the interesting/useful thing that the company is selling. It's common for chemicals to be sold packaged with solvents to make a solution. Sometimes that solvent is just water, but if the product is not water-soluble in sufficient concentrations then other solvents may be necessary. Alcohol solutions are quite common, but for more hydrophobic chemicals it may be necessary to use more &quot;exotic&quot; solvents.</p>\n<p>Because chloroform is quite a dangerous chemical for people to be exposed to and because this product is mostly chloroform, the MSDS is also primarily based on chloroform, not SM-102.</p>\n<p>You can see this in some of the language in the MSDS itself, for example:</p>\n<blockquote>\n<p>Hazard-determining components of labeling:\nChloroform</p>\n</blockquote>\n<p>(this notes that the hazards listed below it are attributable to the presence of chloroform in the packaging)</p>\n<p>and</p>\n<blockquote>\n<p>· Chemical characterization: Mixtures · Description: Mixture of the\nsubstances listed below with nonhazardous additions</p>\n<p>· Dangerous\ncomponents: CAS: 67-66-3 RTECS: FS9100000 Chloroform 90.0%</p>\n<p>· Other\ningredients 2089251-47-6 SM-102 10.0%</p>\n</blockquote>\n<p>You'd have the same hazards listed on the MSDS of 10% water and 90% chloroform. Presenting this as an argument about vaccine safety seems misleading at best.</p>\n<p>From this <a href=\"https://www.fda.gov/media/144637/download\" rel=\"noreferrer\">fact sheet</a>:</p>\n<blockquote>\n<p>Each (0.5 mL dose) dose of the Moderna COVID-19 Vaccine contains the following ingredients: a total lipid\ncontent of 1.93 mg (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG],\ncholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]), 0.31 mg tromethamine,\n1.18 mg tromethamine hydrochloride, 0.043 mg acetic acid, 0.20 mg sodium acetate trihydrate,\nand 43.5 mg sucrose.</p>\n</blockquote>\n<p>(the section in parenthesis is added by me from the previous section)</p>\n<p>Chloroform is not listed as an ingredient in the Moderna vaccine, and determinations about the safety of the vaccine should not be based on MSDS for a product that is 90% chloroform.</p>\n", "score": 49 } ]

[ "covid-19", "vaccination", "safety", "lipids" ]

[ { "answer_id": 424, "body": "<p><strong>Background</strong><br>\nIn the past 10-15 years, thinking on calcium supplementation has shifted significantly. In 2001, a <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11176917/\">National Institutes of Health (NIH) Consensus Development Panel on Osteoporosis</a> made the recommendation that calcium should be supplemented to maintain daily intake 1000 - 1500 mg/day in older adults. The reasoning behind this was that calcium is crucial for maintaining bone mass, which tends to deteriorate during the aging process, leaving this group at increased risk for fractures. The panel acknowledged that most older adults do not obtain this amount of calcium from their diet; they therefore suggested supplementation to this level. </p>\n\n<p><strong>Emerging Skepticism</strong><br>\nSince the NIH recommendation in 2001, several large randomized controlled trials (RCTs) have called into question the efficacy of calcium supplementation to prevent fractures. Although <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17720017\">total fracture risk appears to be marginally reduced</a>, the data suggested that hip fractures, which cause the most significant morbidity and mortality, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18065599/\">are not prevented with calcium supplementation</a>.</p>\n\n<p><strong>Possible Risks</strong><br>\nIn addition to questions about efficacy, concerns have been raised about <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18198394/\">possible increase in cardiovascular events</a> in those receiving calcium supplements, especially women. In <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18198394/\">one RCT</a>, postmenopauasal women were randomized to calcium supplementation or placebo. The <a href=\"http://en.wikipedia.org/wiki/Rate_ratio\">rate ratio</a> of myocardial infarction was 1.67 in the calcium group compared to placebo.¹ </p>\n\n<p><strong>Current State of Affairs</strong> <br> \nIn 2013 the US Preventive Services Task Force issued <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23440163/\">a statement</a> recommending against calcium supplementation for primary prevention² of fractures.</p>\n\n<p><strong>Summary</strong><br>\nCalcium supplementation has questionable efficacy for reducing clinically important fractures, and there is evidence to suggest that it may increase cardiovascular risk. Because of these factors, large groups of smart people who spend their lives analyzing epidemiological data (<em>read</em>: the <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23440163/\">USPSTF</a>) do not recommend calcium supplementation for primary prevention.</p>\n\n<hr>\n\n<p>_{\n<strong>Notes</strong> (a.k.a. <em>my shameless plug for epidemiology education</em>)<br>\n}<br>\n_{\n1. From such data we get headlines: <strong>Calcium increases the risk of heart attack by 167%!</strong> When you see these things, have a look at <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18198394/\">the abstract</a> with special attention to the <a href=\"http://en.wikipedia.org/wiki/Confidence_interval\">confidence interval</a>. Here, the interval was 0.98-2.87. Because it crosses 1, this is actually considered a not <a href=\"http://en.wikipedia.org/wiki/Statistical_significance\">statistically significant result</a>. Although the trend is there, and similar results have been reproduced, this broad confidence interval at least warrants some caution when thinking about <em>what the risk really is</em>. When interpreting data about rare outcomes, calculation of the <a href=\"http://www.patient.co.uk/health/absolute-risk-and-relative-risk\">Absolute Risk</a> is also worthwhile for perspective.<br>\n}<br>\n_{\n2. <a href=\"http://en.wikipedia.org/wiki/Preventive_healthcare#Primary_prevention\">Primary prevention</a> refers to measures to avert an undesirable outcome in people with no history of a such a problem (here, fractures). This stands in contrast to <a href=\"http://en.wikipedia.org/wiki/Preventive_healthcare#Secondary_prevention\">secondary prevention</a>, which involves a population who has already experienced one incident where the goal is to prevent recurrence. The latter group is expected to be at higher risk given their demonstrated propensity for the outcome. For this reason, measures that incrementally decrease this risk tend to provide more absolute benefit compared to primary preventative measures. This is based on the principle that <a href=\"http://en.wikipedia.org/wiki/Absolute_risk_reduction\">absolute risk reduction</a> depends on baseline risk, an important concept to understand when evaluating this literature.<br>\n}<br>\n_{\n<strong>References</strong><br>\n}<br>\n_{\nBischoff-Ferrari, HA et al. 2007. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18065599/\"><em>Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials.</em></a> The American journal of clinical nutrition 86(6):1780–90.<br>\n}<br>\n_{\nBolland, MJ et al. 2008. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18198394/\"><em>Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial.</em></a> BMJ 336(7638):262–66.<br>\n}<br>\n_{\nMoyer, V. A., U.S. Preventive Services Task Force. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23440163/\"><em>Vitamin D and calcium supplementation to prevent fractures in adults: U.S. Preventive Services Task Force recommendation statement.</em></a> Annals of internal medicine 158(9):691–96.<br>\n}<br>\n_{\nNIH Consensus Development Panel on Osteoporosis Prevention, Diagnosis, and Therapy. 2001. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11176917/\"><em>Osteoporosis prevention, diagnosis, and therapy.</em></a> Pp. 785–95 in, vol. 285.<br>\n}<br>\n_{\nTang, BMP et al. 2007. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17720017\"><em>Use of calcium or calcium in combination with vitamin D supplementation to prevent fractures and bone loss in people aged 50 years and older: a meta-analysis.</em></a> Lancet 370(9588):657–66.<br>\n}</p>\n", "score": 17 } ]

[ "nutrition", "micronutrients", "cardiovascular-disease", "musculoskeletal-system", "calcium" ]

[ { "answer_id": 358, "body": "<h2>Modern Science</h2>\n<p>According to the <a href=\"http://www.nhlbi.nih.gov/health/health-topics/topics/sdd/why\" rel=\"noreferrer\">National Heart, Lung and Blood Institute</a>, sleep is certainly needed, that too quality sleep for certain hours. 4-5 hours seems less to me.</p>\n<p>It says --</p>\n<blockquote>\n<p>Studies show that a good night's sleep improves learning. Whether you're learning math, how to play the piano, how to perfect your golf swing, or how to drive a car, sleep helps enhance your learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative.</p>\n<p>Studies also show that sleep deficiency alters activity in some parts of the brain. If you're sleep deficient, you may have trouble making decisions, solving problems, controlling your emotions and behavior, and coping with change. Sleep deficiency also has been linked to depression, suicide, and risk-taking behavior.</p>\n</blockquote>\n<p>Furthermore,</p>\n<blockquote>\n<p>Sleep plays an important role in your physical health. For example, sleep is involved in healing and repair of your heart and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke.</p>\n<p>Sleep deficiency also increases the risk of obesity. For example, one study of teenagers showed that with each hour of sleep lost, the odds of becoming obese went up. Sleep deficiency increases the risk of obesity in other age groups as well.</p>\n</blockquote>\n<p><a href=\"http://www.theguardian.com/science/2013/feb/25/sleeping-six-hours-night-activity-genes\" rel=\"noreferrer\">The Guardian</a> reports that <em><strong>less than six hours</strong></em> of sleep affect the genes. And, there are many drawbacks as well.</p>\n<p>About celebs or known personalities sleeping <strong>4 hours</strong> and working perfectly okay is considered as a <strong>myth</strong>!</p>\n<p>WebMD, in its <a href=\"http://www.webmd.com/sleep-disorders/features/7-myths-about-sleep\" rel=\"noreferrer\">&quot;7 Myths About Sleep&quot;</a> mentions...</p>\n<blockquote>\n<p>Legendary short sleepers — including Bill Clinton, Madonna, and Margaret Thatcher — don't necessarily do better on fewer Zs. &quot;They're just not aware of how sleepy they are,&quot; says Thomas Roth, Ph.D., sleep researcher at Henry Ford Hospital in Detroit. Too little sleep is bad for your health and your image: It can make you ineffective (it impairs performance, judgment, and the ability to pay attention), sick (it weakens your immune system), and overweight. In fact, women who slept five hours or less a night were a third more likely to gain 33 pounds or more over 16 years than women who slept seven hours, according to a Harvard Nurses' Health Study. Oddly, cutting too much sleep and getting less than six hours is associated with the same problems as sleeping too long: a higher risk of heart problems and death. And, of course, cheating on sleep hurts you behind the wheel: &quot;Wakefulness for 18 hours makes you perform almost as though you're legally drunk,&quot; says Walsleben.</p>\n</blockquote>\n<p>In an article on <a href=\"http://www.dailymail.co.uk/health/article-2157461/Less-6-hours-sleep-significantly-increases-risk-stroke-fit-healthy.html\" rel=\"noreferrer\">DailyMail.co.uk,</a> it says that less than 6 hr of sleep increases the risks of having stroke <strong>even if you are fit and healthy</strong>. That said, those sleeping for less hours <em>might look fit</em>, but they are at the risks of something fatal.</p>\n<p>[For those who believe <em>only</em> in evidences, the answer <strong>ends</strong> here]</p>\n<hr />\n<p>[For those who believe more in traditional medicines, folk medicines and alternative medicines than researches, Ayurveda has an explanation]</p>\n<h2>Ayurvedic Aspect</h2>\n<p>There's something called 'satmya (saa-t-m-ya)'. In Ayurveda, it's described that if you start 'practicing' something with your body, your body 'gets adjusted' and it does not suffer the way others suffer with 'that practice'. In other words, I have been eating potatoes both the times for past 35 years <strong>AND</strong> it does not cause <em>any harm</em> to my body. It <strong>has become</strong> an integral part of my life and my body <strong>considers</strong> it as 'natural thing'.</p>\n<p>Said that, if someone, right from his/her childhood or early adulthood has started practicing sleeping for a few hours, the body adjusts to it, and they find <strong>no</strong> problem with sleeping less <strong>as compared to</strong> those sleeping for 8 hrs regularly (from their childhood/early adulthood).</p>\n<p>In my practice, I've seen people with more than 140 sugar, or 140/100 mmHg blood pressure <strong>with absolutely no signs</strong> of deteriorated health. While modern science finds it difficult to answer, Ayurveda says that the body has adjusted to whatsoever conditions it's living in.</p>\n", "score": 10 }, { "answer_id": 348, "body": "<p>This question can be approached from many levels. There are many physiological factors having influence to sleeping of which circadian rhytm is one of the most important. Messing with your circadian rhytm would take guru's strength of mind.</p>\n\n<p>In a population level I would say it is not possible. I have two aspects for this.</p>\n\n<p>1) In year 2015 we are able to teleport photons and each person on Earth carries thousands times more sophisticated computer chips in their pockets than it took to land on Moon. However we still dont know exactly WHY we have to sleep. Of course there is increasing knowledge regarding those physiological activies which happen during sleep but the very basic reason for sleep is unknown. As so, in my opinion we should thoroughly establish the very basic ideology in sleep in order to reduce itś duration from the average 7-8 hours a day</p>\n\n<p>2) Millions of years of evolution has brought us here. Some few ten thousands of years ago it was dangerous to sleep. You had to minimize your sleep time since all that time you were vulnerable to your fellow primitive humans and wild animals. Whether humans slept less in those days or not, I can´t say. However is not influecing today's humans when obviously we are living quite different times. But I think that if it was possible to reduce sleep hours from 7-8 to, say, 4-5 hours a day this ability would have developed during evolution. This ability may also have diminished during evolution, but again that would have happened due to changing enviroment we are living and reduced sleep for modern human would be nearly impossible in population level.</p>\n\n<p>Of course if we are looking from individual level, sure it could be possible to sleep less. You can start reducing your sleeping time and see the effects. Some of us can run 100m in less than 9.80 seconds, someone can run a marathon in less than 2:10 and someone can benchpress over 300kgs. But in population level I would say it is not possible to permanently reduced sleeping time.</p>\n", "score": 4 } ]

[ "sleep" ]

[ { "answer_id": 471, "body": "<p>There is some evidence that sugar does suppress the immune system. The <a href=\"http://ajcn.nutrition.org/content/26/11/1180.abstract\">study that everyone seems to point to</a> was conducted in 1973, where they fed sugar in 100g doses to people and measured the effect on phagocytosis (where immune cells engulf invader bacteria to destroy it).</p>\n\n<p>The end result was that sugar intake did appear to suppress the ability of the immune system to destroy invading bacteria. This function was suppressed for up to 5 hours in control subjects, while fasting comparisons did not have the same effect. Additionally, they counted the number of neutrophils (type of white blood cells), and they were not diminished, which suggests it was a function blocking mechanism, not that it suppressed the number. So it does limit the effectiveness, but this is not really a suppression of the system.</p>\n\n<p>Part of this may be due to the sugar molecule being structurally similar to Vitamin C (Ascorbic acid), and that it competes for the space and prevents the cells from effectively using Vitamin C to destroy bacteria. (Based off studies Linus Pauling did, but I could not find the study, merely references to it).</p>\n\n<p>There are suggestions that sugar also <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17709452?dopt=Abstract\">may contribute to insulin resistence</a>, and that it may <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17402291?dopt=Abstract\">contribute to increased inflammation</a>, but these either state more study is needed or are in the incidence of specific other deficiencies (Such as magnesium).</p>\n", "score": 7 } ]

[ "nutrition", "diet", "immune-system" ]

[ { "answer_id": 557, "body": "<p>This seems like a difficult question as there <a href=\"http://www.the-scientist.com/?articles.view/articleNo/34110/title/Is-Cannabis-Really-That-Bad-/\">continues</a> to be a <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22927402\">large</a> <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23319626\">amount</a> of <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16054989\">conflicting</a> <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19004418\">reports</a> about the extent of biological\n consequences regarding cannabis usage.</p>\n\n<p>However,</p>\n\n<ul>\n<li>There is general consensus that smoking cannabis causes irreversible cognitive impairment in <strong>children and pre-pubescent\nadolescents</strong>. <a href=\"http://www.aerzteblatt.de/int/archive/article?id=127603\">{6}</a></li>\n<li>Marijuana smoke has been listed on the California Proposition 65<br>\nwarning list as a carcinogen since 2009. <a href=\"http://www.oehha.ca.gov/prop65/prop65_list/files/P65single060614.pdf\">{7}</a> One should note this is the smoke, not the plant.</li>\n<li><p>Cannabis consumption in pregnancy is associated with restrictions in\ngrowth of the fetus, miscarriage, and cognitive deficits in\noffspring. <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3818851/\">{8}</a></p></li>\n<li><p>Contrary to common belief, marijuana can be addictive. Research\nsuggests that about 1 in 11 users becomes addicted to marijuana\n(Anthony, 1994; Lopez-Quintero 2011).This number increases among\nthose who start as teens (to about 17 percent, or 1 in 6) and among\npeople who use marijuana daily (to 25-50 percent) (Hall, 2009a; Hall,\n2009b).<a href=\"http://www.drugabuse.gov/publications/drugfacts/marijuana\">{9}</a></p></li>\n</ul>\n\n<p>Given the above references, there are some points that should be emphasized.</p>\n\n<ul>\n<li>Marijuana use is not associated with elevated cancer risk as shown\nin preclinical studies.<a href=\"http://www.drugpolicy.org/drug-facts/10-facts-about-marijuana\">{10}</a>\n<a href=\"http://www.washingtonpost.com/wp-dyn/content/article/2006/05/25/AR2006052501729.html\">(Separate link to news article here.)</a></li>\n<li>[Marijuana does not cause long-term cognitive impairment in users who\nstart after 21 years old.<a href=\"http://www.drugpolicy.org/drug-facts/10-facts-about-marijuana\">{12}</a></li>\n<li>Compared to other substances, marijuana is not very addicting. It is\nestimated that 32% of tobacco users will become addicted, 23% of\nheroin users, 17% of cocaine users, and 15% of alcohol users. Cocaine\nand heroin are more physically harmful and nicotine is much more\naddictive. It is much harder to quit smoking cigarettes than it is to\nquit smoking pot.</li>\n</ul>\n\n<p>There are some studies that indicate <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23280514\">\"marijuana may increase cravings for other drugs\"</a> and that <a href=\"http://www.ncbi.nlm.nih.gov/pubmed?term=10.1038%2Fnpp.2013.16\">\"THC exposure increases tobacco’s addictive effects\"</a>, which is what leads to the Gateway Drug Theory. This is the theory that marijuana causes an individual to become addicted to other drugs more easily. Although not fully proven, these sources indicate some correlations when tested on mice, meaning people who use marijuana may be more likely to get addicted to cocaine, heroin, and other similar heavily addicting drugs. This sounds frightening except that the majority of people don't try those more dangerous drugs.</p>\n\n<p>Boiling it all down, these sources seem to suggest that marijuana is NOT a carcinogen if you don't smoke it, but does cause mental and physical detriments to anyone still growing. There's a small chance you could get addicted if you use it as a coping mechanism, but statistically speaking, there's a less than 10% chance of getting addicted. Additionally, if you decide to use marijuana, don't try other drugs that could be addictive.</p>\n", "score": 12 } ]

[ "smoking", "marijuana", "recreational-drugs" ]

[ { "answer_id": 1281, "body": "<p>Assuming the person is not taking anticoagulants, it's actually quite difficult to bleed to death from dismemberment of small members (hands, feet, penis, ears, nose, etc). Even large members such as arms and legs are often survivable because the body is very good at protecting itself from blood loss. For example, transected arteries will spasm and clamp off blood flow, and loss of blood will cause the body to divert blood flow away from the extremities and to the vital organs, thereby slowing the bleeding and allowing it to clot. In fact, the whole shock process can be viewed as a set of defensive measures by the body to ensure survival in the face of serious injury. This was a bitter lesson learned by emergency medicine only fairly recently. The standard practice used to be to infuse hypovolemic patients with fluids to maintain normal blood pressure. The trouble is, a normal blood pressure prevents the body from realizing it has inadequate blood volume and turns off its defensive measures, thus allowing the bleeding to continue unabated. </p>\n\n<p>Left to fend for himself, a healthy adult would almost certainly survive having his penis removed. With modern medical care, that becomes a certainty.</p>\n\n<p>Could he still urinate? Sure, as long as the urethra wasn't blocked. It could become blocked by clotted blood, but eventually the pressure of a full bladder would overcome the blockage.</p>\n", "score": 30 }, { "answer_id": 8820, "body": "<p>The problem is there are too many unknowns. First, the speed of clotting varies from person to person. There are lab tests that measure clotting time (e.g. INR), especially useful when a patient takes anticoagulants. One respondent mentioned the absence of anticoagulants, but anticoagulants include substances not specifically prescribed to reduce clotting, such as supplements and even food items that reduce clotting. Further, there are genetic factors (i.e. Factor VIII and others) that modulate clotting time, operating independently of medical intervention/prescribed drugs or anything consumed. Age is another facet in the clotting process, as infants often do not clot quickly. Couple that fact with the smaller quantity of blood in an infant's body and it makes sense why some infants actually die from circumcision related bleeding. An infant may retain his penis after circumcision but still die from operation related blood loss.</p>\n\n<p>Additionally, the penis is different than other appendages and extremities. Besides the difference in tissue composition (smooth muscle vs. skeletal muscle elsewhere), penile arteries dilate more than arteries elsewhere and veins constrict more than veins elsewhere (assuming one has generally healthy blood vessels prior to injury). The unique elasticity of penile blood vessels mean that a traumatic injury like penile amputation is more likely to bleed continuously than many other amputations when taking into account the relative area of tissue amputated and blood vessels severed. Other than the femoral or carotid arteries, which, due to their own unique locations, are more likely to cause death from dissection than severing other arteries, the penis is again unique in that the arteries both inside and leading to it do not always clamp off- sometimes, they remain dilated even after a severing injury.</p>\n\n<p>One of the biggest factors of survival (a somewhat controllable factor) in this case is time. The more time elapses after amputation without subsequent medical intervention, the more likely death becomes. </p>\n\n<p>Death from penile amputation can arise not simply from blood loss but also from related issues such as overall stress and pain. Stress hormones and an inflammatory chemical cascade following such a traumatic injury can overwhelm the heart. </p>\n", "score": 6 } ]

[ "removal", "urinary-system", "penis", "death" ]

[ { "answer_id": 3900, "body": "<p>There are actually quite a lot of studies pointing in all directions when it comes to memory and caffeine use. I wouldn't call it a closed case by any standard, although many sites hawk caffeine as a great improver of memory, especially long-term memory.</p>\n<p><strong>Some studies showing no effects of long-term caffeine use on memory:</strong></p>\n<ul>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12404609\" rel=\"noreferrer\">Hameleers et al. (2000)</a>: A large number of adults (1875) ranging in age from 21 to 84 were studied while consuming caffeine over long periods of time. Even after compensation for various medical and sociological factors, no effects on short-term memory were observed. The sheer amount of data gathered is one thing in favor of this study, as outliers would not have influenced the result.</li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/10458050\" rel=\"noreferrer\">Herz (1999)</a>: A large number of subjects were studied while undergoing certain sessions containing cognitive tasks. No effects on memory were observed from caffeine usage.</li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/7675951\" rel=\"noreferrer\">Warburton (1995)</a>: Low doses of caffeine were used on subjects over an extended period of time. There were non-negligible mood changes, but no effects on working memory. Note that this study focused in part on caffeine deprivation, rather than giving subjects additional caffeine.</li>\n</ul>\n<p><strong>Some studies showing positive effects of long-term caffeine use on memory:</strong></p>\n<ul>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12424493\" rel=\"noreferrer\">Angelucci et al. (2002)</a>: A group of rats (not humans!) was studied, given caffeine injections at various points during training. They were then given the <a href=\"https://en.wikipedia.org/wiki/Morris_water_navigation_task\" rel=\"noreferrer\">Morris water maze test</a>. Some of the rats were able to better remember pervious sessions - as the authors put it,\n<blockquote>\n<p>These data provide evidence that caffeine improves memory retention but not memory acquisition, explaining some discrepancies among reports in the literature.</p>\n</blockquote>\n</li>\n<li><a href=\"http://jn.nutrition.org/content/144/6/890.abstract\" rel=\"noreferrer\">Beydoun et al. (2014)</a>: Caffeine and alcohol use and diet were studied simultaneously in a large group of subjects. The findings were mixed, although some evidence was found supporting the hypothesis that caffeine use can increase overall cognitive function in older adults.</li>\n</ul>\n<p><strong>Some studies showing negative effects of long-term caffeine use on memory:</strong></p>\n<ul>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17400186\" rel=\"noreferrer\">Han et al. (2007)</a>: Subjects were studied over four weeks while using low doses of caffeine. A slight decrease in memory function was observed, caused in part by inhibition of part of the hippocampus.</li>\n</ul>\n<p>I haven't shown the same amount of studies in all three categories - neutral, positive, and negative - and that's by design. There is a substantial amount of studies that found no significant effects, and that much more research would be needed to give strong evidence for long-term benefits. There is a decent amount of studies showing some positive long-term benefits, and almost none showing negative long-term benefits.</p>\n<p>Therefore, I don't think it's safe to go in any of the three directions. However, it does seem like the effects of long-term caffeine use may be negligible.</p>\n<p>Also, be careful to differentiate between long-term effects of caffeine on memory and the effects of caffeine on long-term memory! Studies often cover both, because studying subjects over only a few days won't tell you much about long-term memory (certainly not about acquisition, at least). However, they aren't the same thing.</p>\n", "score": 9 } ]

[ "caffeine", "drug-metabolism", "memory" ]

[ { "answer_id": 3814, "body": "<p>Like all things too much of anything is bad for you. As a designer working in the tech industry for over a decade, here's a few things I experienced and that might (I hope not) impact you. </p>\n\n<ul>\n<li>wrists from over use of keyboard and mouse</li>\n<li>circulation problems from being seated for too long</li>\n<li>eye sight</li>\n<li>posture problems</li>\n<li>social effects of not going out and socializing but using social media to socialize (which isnt really socializing)</li>\n</ul>\n\n<p>Sources:</p>\n\n<ol>\n<li>(study on carpal tunnel syndrome- wrists)\n<a href=\"http://jama.jamanetwork.com/article.aspx?articleid=196717\" rel=\"noreferrer\">http://jama.jamanetwork.com/article.aspx?articleid=196717</a></li>\n<li>(computer vision syndrome)\n<a href=\"http://www.webmd.com/eye-health/computer-vision-syndrome\" rel=\"noreferrer\">http://www.webmd.com/eye-health/computer-vision-syndrome</a></li>\n<li>(American Optometric Association)\n<a href=\"http://www.aoa.org/Documents/optometrists/effects-of-computer-use.pdf\" rel=\"noreferrer\">http://www.aoa.org/Documents/optometrists/effects-of-computer-use.pdf</a></li>\n<li>(sitting &amp; posture)\n<a href=\"https://www.washingtonpost.com/apps/g/page/national/the-health-hazards-of-sitting/750/\" rel=\"noreferrer\">https://www.washingtonpost.com/apps/g/page/national/the-health-hazards-of-sitting/750/</a></li>\n<li>(social interaction) <a href=\"https://www.elon.edu/docs/e-web/academics/communications/research/vol6no1/02DragoEJSpring15.pdf\" rel=\"noreferrer\">https://www.elon.edu/docs/e-web/academics/communications/research/vol6no1/02DragoEJSpring15.pdf</a></li>\n</ol>\n", "score": 8 } ]

[ "sleep", "eye", "computers", "lifestyle" ]

[ { "answer_id": 10772, "body": "<p>In medical documentation, being an X-ray, MRI, description of physical examination or other, the sides \"right\" and \"left\" should be always used as they appear in your body. So, the \"left neural foramen\" is on your left-hand side.</p>\n\n<p>Below is an X-ray image of the chest cavity. You can see the big letter \"L\" and all the \"left\" terms on the right side of the image, because this is a view from the front, so they are all point to the left parts of the body. The confusion could occur when someone points to the image and just says \"here on the left,\" without saying \"side of the body \" or \"image.\" Anyway , when a doctor says something is on the left side, it should be always on <em>your</em> left.</p>\n\n<p><a href=\"https://i.stack.imgur.com/B0MCm.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/B0MCm.jpg\" alt=\"An X-ray image of the chest showing the letter L on the side where the heart is\"></a> (Source: <a href=\"http://lifeinthefastlane.com/investigations/cxr-normal/\" rel=\"noreferrer\">Lifeinthefastline</a>, CC licence)</p>\n", "score": 22 } ]

[ "practice-of-medicine", "position" ]

[ { "answer_id": 21379, "body": "<p>Short answer: Sophie Trudeau's positive test <em>may</em> still mean 3 : 1 odds of <em>not</em> having contracted Covid-19, but the odds could also be far more towards having Covid-19.<br>\nJustin Trudeau's negative test almost certainly means he was negative when tested. Of course, should Sophie be positive, that may have changed by now.</p>\n\n<hr>\n\n<p><strong>Update:</strong> I found a web page of the <a href=\"https://www.fda.gov/medical-devices/emergency-situations-medical-devices/emergency-use-authorizations#covid19ivd\" rel=\"nofollow noreferrer\">FDA listing tests that have this Emergency Use Approval</a>. Each of them has manufacturer instuctions that list their test results towards the end. Some of the submitted test results use ≈100 negative samples in the clinical evaluation. But there is also one that has only 13 positive cases (all of which were correctly found) in their test - but that one got the emergency approval already early in February.<br>\nThe latest 2 (by Thermo and Roche) used 60/60 and 50/100 cases for their clinical evaluation (all results correct). That gets the lower end of the confidence intervals for sensitivity and specificity to 94 - 97 % (with the lower end of the c.i. we'd thus have LR+ >≈ 20 or 17, expected values would be 61 or 51, respectively. For LR- &lt;≈ 1/20 or 1/32 (expected 1/61 or 1/100). </p>\n\n<hr>\n\n<p>Long version: Let's do some number juggling and see whether we can extract something useful. The following calculations are based on a somewhat worst-case scenario: the FDA emergency validation guidelines specify outcomes that such a new test in the current emergency situation must meet, and I calculate from the low end of performance that could be expected meet these criteria under somewhat unlucky circumstances.</p>\n\n<p>So we know minimum performance requirements, but I do not know [yet] how good (= how much better than minimum performance) the tests are.</p>\n\n<h3>Sensitivity and Specificity</h3>\n\n<p>The starting point would be <a href=\"https://en.wikipedia.org/wiki/Sensitivity_and_specificity\" rel=\"nofollow noreferrer\">sensitivity and specificity</a> of the respective test. I haven't found any published data on these, but the FDA has a <a href=\"https://www.fda.gov/media/135659/download\" rel=\"nofollow noreferrer\">Policy for Diagnostics Testing for Coronavirus Disease-2019</a> that says how labs that develop a test should do an \"emergency validation\". They can then get Emergency Use Approval. </p>\n\n<ul>\n<li><strong>Sensitivity</strong> tells us: of all truly Covid-19-positive specimen, which percentage is correctly recognized as positive by the test; I'm going to use <strong>87.5 %</strong> (see below)</li>\n<li><strong>Specificity</strong> tells us: of all specimen that are truly negative for Covid-19, which percentage is correctly recognized by the test.</li>\n</ul>\n\n<p>Sensitivity and specificity can be measured by standardized protocols, and they characterize the performance of the test. </p>\n\n<p>From a patient's or doctor's point of view, however, they are not very useful numbers as they (we) need the answer to the inverse questions:</p>\n\n<h3>Predictive values</h3>\n\n<ul>\n<li><strong>positive predictive value PPV:</strong> given that the test yielded <em>positive</em>, what is the probability that the patient truly has the virus?</li>\n<li><strong>negative predictive value NPV:</strong> given that the test yielded <em>negative</em>, what is the probability that the patient truly does not have the virus?</li>\n</ul>\n\n<p>Predictive values can be calculated from sensitivity and specificity together with the <a href=\"https://en.wikipedia.org/wiki/Prevalence\" rel=\"nofollow noreferrer\">prevalence</a> (or, as we are talking about newly infected patients, the <a href=\"https://en.wikipedia.org/wiki/Incidence_(epidemiology)\" rel=\"nofollow noreferrer\">incidence</a>) of virus among the tested population. Here's how they go for the assumed sensitivity and specificity:</p>\n\n<p><a href=\"https://i.stack.imgur.com/p75G6.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/p75G6.png\" alt=\"predictive values\"></a><br>\nred for positive test outcomes, dark green for negative test outcomes. posterior probability = <em>after</em> the test said something, what is the probability that the test result is correct = NPV for negative test result, PPV for positive test result.</p>\n\n<p>Good estimates of prevalence are often difficult to obtain, because we need the prevalence among those who are tested and that is (and should be) quite different from the prevalence of the disease in the general population. </p>\n\n<p>For some countries such as <a href=\"https://github.com/pcm-dpc/COVID-19/blob/master/schede-riepilogative/regioni/dpc-covid19-ita-scheda-regioni-20200314.pdf\" rel=\"nofollow noreferrer\">Italy, we have numbers of performed tests</a> (<a href=\"https://en.wikipedia.org/wiki/COVID-19_testing\" rel=\"nofollow noreferrer\">Wiki page giving numbers for more countries</a>): as of today (March 14th), they ran 109170 tests and have a total of 21157 cases. Not all tests are for initial diagnosis (AFAIK, a patient is considered cured only after a bunch of tests are negative), but as most cases are still \"fresh\", we may the ratio positive cases : tests run as one surrogate for the prevalence in the tested population. This would be around 20 % for Italy. </p>\n\n<p>From the diagram we can then read for a new patient being tested the first time:</p>\n\n<ul>\n<li>if the test outcome is <em>positive</em>, chances are ≈ 75 % (or greater as I'm calcluating with the lower end of the possible range from the emergency validation) that the patient really has Covid-19.<br>\nSo, up to 25 % false positives. </li>\n<li>if the test outcome is <em>negative</em>, chances are ≈ 95 % (or greater...) that the patient really does not have Covid-19.<br>\nSo, up to 5 % false negatives. </li>\n</ul>\n\n<p><a href=\"https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection.html\" rel=\"nofollow noreferrer\">Canada</a> currently reports 25 positive out of a total of 796 tests, so about 3 % prevalence in the tested population.</p>\n\n<p>For the USA, the CDC reports <a href=\"https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html\" rel=\"nofollow noreferrer\">case numbers</a> and <a href=\"https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/testing-in-us.html\" rel=\"nofollow noreferrer\">test numbers</a>, currently 1629 cases with (3995 + 15749) tests - but it is not entirely clear to me whether the populations completely coincide. Anyways, I'll use 8 % as guesstimate for prevalence.</p>\n\n<pre><code>| prevalence | PPV | NPV | Country/Population | \n+------------+------+--------+--------------------+\n| 3 % | 26 % | 99.6 % | Canada |\n| 8-9 % (?) | 50 % | 98.8 % | USA, Germany |\n| 20 % | 75 % | 95 % | Italy |\n\n</code></pre>\n\n<p>Now that is the population of \"everyone who is tested\". At least for Germany (March 14th) but probably also for Canada and the US, tests are done on people who show symptoms and on people that are known to have had contact with Corona virus cases: if they are found to be positive, they are sent home to quarantine and wait whether they did acutally catch the disease. But we may still say that the \"people who are tested\" population has subpopulations with and without symptoms.<br>\nSo if there are further point of suspicion, say, the patient does cough, we'd say they belong to a high risk subpopulation with higher prevalence of Covid-19 compared to the overall prevalence among tested, so the chance of a false positive would be lower for them. </p>\n\n<p>This will change as tests are performed only on people who show symptoms (by now, March 16th, everyone is already told to stay at home in Germany and self-isolate as well as possible - the test result will not change this in any way). </p>\n\n<h3>Handy for quick calculation: <a href=\"https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing\" rel=\"nofollow noreferrer\">likelihood ratio positive (LR+) and negative (LR-)</a></h3>\n\n<p>If we express the prevalence as odds (1 : 99 instead of 1 %), LR+ and LR- allow easy back-of-the envelope calculations. </p>\n\n<p>LR+ = sensitivity / (1 - specificity) ≈ 11 or better for our test and \nLR- = (1 - sensitivity) / specificity ≈ 0.05 = 1/20 or better for our test.</p>\n\n<p>so they are indpendent of the prevalence and they tell us how the odds change due to the test: the posterior probability (predictive values) are the the pre-test odds multiplied with the likelihood ratio. In that sense, they tell us how much information we gain due to test (for positive and negative outcomes).</p>\n\n<p>So, Canada reported odds of 25 positive : 771 negative tests. So for Sophie Trudeau, the odds went from 25 : 771 (or 3 %) to 25 : 771 * 11 = 273 : 771 ≈ 1 : 3 or 25 %. For Justin Trudeau 25 : 771 / 20 = 25 : 15420 ≈ 1 : 617 or 0.16 % of being Covid-19 positive (slight discrepancy to above due to rounding).</p>\n\n<p>On the other hand, if we start testing more and more people for whom the risk of actcually having contracted the virus is lower and lower, we soon won't be able to draw meaningful conclusions from the test results any more: I'm in Germany, currently the <a href=\"https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Fallzahlen.html\" rel=\"nofollow noreferrer\">federal info page</a> lists 3800 confirmed cases. Even if we assume that there is a huge dark figure and in reality 20 x as many people are infected* that would be a prevalence in the general population of 0.1 %, the odds are 1 infected : 1.5 mio non-infected. If someone who does not belong to any particular risk group were tested positive, their odds would increase by factor 11, i.e. roughly 1 : 140000. A negative test result would decrease the odds by a factor of 1/20 to 1 : 31 mio. However, both results are of no practical use as they don't change the situation: pre-test situation is \"very unlikely to be Covid-19 case\", post-test situation is still \"very unlikely to be Covid-19 case\".</p>\n\n<p><strong>This is why, even if there were testing capacities for the whole population, tests don't make sense unless we know there are some risk factors such as some kind of respiratory disease or contact to someone who is known to have the virus.</strong> And why it is sensible to say that on slightly suspicious circumstances (= low, but not extremely low prevalence), one should self-quarantine/avoid contact but there's no point in testing [yet].</p>\n\n<hr>\n\n<h3>Detais on how I estimate sensitivity and specificity</h3>\n\n<ul>\n<li>The lab first determines the limit of detection (LoD) for virus RNA. The LoD here is the lowest concentration at which 19 out of 20 replicate tests are positive (that would be 95 % sensitivity, but for samples spiked in the lab, but with a relevant and as difficult as possible matrix such as sputum). </li>\n<li><p>Next, [leftover] clinical samples are used: </p>\n\n<ul>\n<li><p>As there may not be any positive samples available, the lab can spike negative samples with virus RNA; a minimum of 20 samples are spiked within a range of 1 - 2 LoD plus 10 samples to cover the remaining clinical range.<br>\nOf these, at most 1 is allowed to have negative outcome (and that must be one in the lower concentration range). Thus, 29 positive out of 30 true positive. </p></li>\n<li><p>Also 30 non-reactive specimens are tested. The policy doesn't say a number of false positives that is permissible, so I'm going to assume that must be zero. </p></li>\n</ul></li>\n<li><p>The lab can then start with real patient samples. The first 5 positive and the first 5 negative cases must be confirmed by an approved test (and must all match). </p></li>\n</ul>\n\n<p>Pooling the 2 \"rounds\" of testing clinical samples, we have:</p>\n\n<ul>\n<li>34 (or 35) positive tests out of 35 truly positive specimen -> sensitivity at least 97 % with 95% credible interval 87.5 - 100 %,</li>\n<li><p>specficity 100 % with 95% credible interval 92 - 100 %</p></li>\n<li><p>There are additional checks required but they don't help us here.</p></li>\n<li><p>Sampling errors are not included in this validation.<br>\nI'm <em>not</em> a clinical chemist, but I'm analytical chemist and in general analytical chemistry, that can easily be the dominating source of error. In that case, the above numbers would be useless.</p></li>\n<li><p>Particularly the sensitivity may drop over time as the virus mutates. </p></li>\n<li><p>To deal with this, in some cases multiple tests are done (read that in some newspaper article which I don't find at the moment).<br>\nWhen doing multiple tests, tests by different providers are used if possible: as they are developed from different virus samples, this gives a better coverage for mutations in the virus than doing the same test in replicate.</p></li>\n</ul>\n\n<hr>\n\n<p>* Very handwavy scenario I derived from the <a href=\"https://en.wikipedia.org/wiki/2019%E2%80%9320_coronavirus_pandemic#/media/File:2020_coronavirus_patients_in_China.svg\" rel=\"nofollow noreferrer\">development of case numbers in China after their quarantine/shutdown on Jan 26</a>, assuming an incubation period of 2 weeks and that noone got infected after quarantine started.</p>\n\n<hr>\n\n<p>Update Jun 3rd, 2020:</p>\n\n<ul>\n<li><p><a href=\"https://www.instand-ev.de/System/rv-files/340%20EN%20SARS-CoV-2%20Genome%20EQAS%20April%202020%2020200502j.pdf\" rel=\"nofollow noreferrer\">Results of a round robin test/ring trial in April in Germany on detection of SARS-CoV2 RNA</a> (retrieved from <a href=\"https://www.instand-ev.de/en/eqas-online/service-for-eqa-tests.html#rvp//340/2003/\" rel=\"nofollow noreferrer\">https://www.instand-ev.de/en/eqas-online/service-for-eqa-tests.html#rvp//340/2003/</a>)</p>\n\n<ul>\n<li>7 samples: 4 positive for SARS-CoV2 covering a factor of 1000 in concentration of virus RNA; 3 negative for SARS-CoV: 1 negative for any coronavirus, 1 positive for HCoV OC43 but not SARS-CoV2 and 1 positive for HCoV 229E but not SARS-CoV2.</li>\n<li><p>463 laboratories participated, submitting a total of 983 results per sample (1 lab can submit results for several methods)</p></li>\n<li><p>The final evaluation comprises only 4 out of the 7 samples: while the ring trial was still ongoing, the ground truth and a preliminary evaluation was published for 3 samples in order to allow labs to use the results to adjust their procedure.</p></li>\n<li><p>There was a problem with 24 labs (59 lab×methods) where results for two samples (the positive 1:100000 dilution and the negative with HCoV 22E) were interchanged. </p></li>\n</ul>\n\n<p><em>I'll disregard these two samples for now.</em></p>\n\n<ul>\n<li><p><strong>Specificity</strong> was 969/983 = 98.6 % for the negative and 961/983 = 97.8% for the negative with HCoV OC43 (sample was unblinded).<br>\nThe report notes that it is not clear whether the false positives are a result of the specificity of the method itself or whether they stem from contamination of the test samples with SARS-CoV2 in the labs. </p></li>\n<li><p><strong>Sensitivity</strong> was 980/983 = 99.7 % for the highest (sample was unblinded) and 914/983 = 93.0% for the lowest virus RNA concentration.</p></li>\n</ul>\n\n<p>Such a ring trial measures the performance of diagnostic method and lab handling of the samples together. </p></li>\n<li><p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7066521/\" rel=\"nofollow noreferrer\">Wenling Wang <em>et al.</em>: Detection of SARS-CoV-2 in Different Types of Clinical Specimens, JAMA, 2020 May 12; 323(18): 1843–1844.</a> reports on sensitivity of RT-PCR tests for various sampling procedure/locations. 1070 specimen collected from 205 confirmed Covid-19 patients.<br>\nThey report 5 of 8 nasal swabs (95%c.i. 30 - 90%) to be positive and 126 of 398 pharyngeal swabs (95% c.i. 27 - 36%). <a href=\"https://pubs.rsna.org/doi/10.1148/radiol.2020200642\" rel=\"nofollow noreferrer\">This other study, while not primarily about PCR sensitivity reports about 60 %</a></p>\n\n<p><em>The paper has very few details, e.g. on the point in time when samples were taken.</em></p>\n\n<p>This study measures the sensitivity of method, lab handling and sampling procedure together. </p>\n\n<p>Experts in radion interviews I heard over the last months were talking about sensitivity in the order of magnitude of 70 - 80 % due to difficult sampling (requiring trained staff, preferrably taking 2 swabs [but swabs were scarce at some point], the correct procedure for nasopharyngeal sampling being painful, the correct point in time wrt. the course of the disease)</p>\n\n<p>In any case, the overall sensitivity seems to be dominated by sampling error rather than lab handling or the sensitivity of the RT-PCR.</p></li>\n</ul>\n\n<p>So my initial guesstimates were too optimistic for overall sensitivity, but specificity looks better than the initial worst-case scenario: we have an LR⁺ of around 50, but LR⁻ is only about 1/4.</p>\n\n<p>Important Note: all this is about the <strong>real time PCR tests for virus RNA</strong>. <a href=\"https://medicalsciences.stackexchange.com/questions/23192/why-are-novel-coronavirus-anitbody-tests-disparaged/23469#23469\">Antibody tests have their own and actually quite different characteristics.</a></p>\n", "score": 15 }, { "answer_id": 21554, "body": "<blockquote>\n <p>Is there any figure about the accuracy of COVID-19 tests?</p>\n</blockquote>\n\n<p>A thorough review of prior research found: Using \"<a href=\"https://en.wikipedia.org/wiki/Reverse_transcription_polymerase_chain_reaction\" rel=\"nofollow noreferrer\">rRT-PCR</a>; First-line screening tool: E gene assay; Confirmatory testing: RdRp gene assay.\" one can obtain \"95% detection probability, 100% specificity\".</p>\n\n<p>Reference:</p>\n\n<p>The Journal of Clinical Medicine review: \"<a href=\"https://doi.org/10.3390/jcm9030623\" rel=\"nofollow noreferrer\">Potential Rapid Diagnostics, Vaccine and Therapeutics for 2019 Novel Coronavirus (2019-nCoV): A Systematic Review</a>\", J. Clin. Med. 2020, 9(3), 623 explains:</p>\n\n<blockquote>\n <p>\"A systematic search was carried out in three major electronic databases (PubMed, Embase and Cochrane Library) to identify published studies examining the diagnosis, therapeutic drugs and vaccines for Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and the 2019 novel coronavirus (2019-nCoV), in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.</p>\n \n <p>...</p>\n \n <p>An initial search identified a total <strong>of 1,065 articles</strong> from PubMed, Embase and Cochrane Library. There were 236, 236 and 593 articles related to diagnostics, therapeutics and vaccines, respectively. After reviewing for inclusion and exclusion and the removal of duplications, <strong>a total of 27 studies were used for the full review</strong>.</p>\n \n <p>...</p>\n \n <p>The first <strong>validated</strong> diagnostic test was designed in Germany. Corman et al. had initially designed a candidate diagnostic RT-PCR assay based on the SARS or SARS-related coronavirus as it was suggested that circulating virus was SARS-like. Upon the release of the sequence, assays were selected based on the match against 2019-nCoV upon inspection of the sequence alignment. Two assays were used for the RNA dependent RNA polymerase (RdRP) gene and E gene where E gene assay acts as the first-line screening tool and RdRp gene assay as the confirmatory testing. All assays were highly sensitive and specific in that they did not cross-react with other coronavirus and also human clinical samples that contained respiratory viruses.\"</p>\n</blockquote>\n\n<p>Sources:</p>\n\n<ul>\n<li><p><a href=\"https://dx.doi.org/10.2807%2F1560-7917.ES.2020.25.3.2000045\" rel=\"nofollow noreferrer\">Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR</a>, Euro Surveill. 2020 Jan 23; 25(3): 2000045.</p>\n\n<blockquote>\n <p>\"All assays were highly sensitive, with best results obtained for the E gene and RdRp gene assays (5.2 and 3.8 copies per reaction at <strong>95% detection probability</strong>, respectively). These two assays were chosen for further evaluation. One of the laboratories participating in the external evaluation used other basic RT-PCR reagents (TaqMan Fast Virus 1-Step Master Mix) and repeated the sensitivity study, with equivalent results (E gene: 3.2 RNA copies/reaction (95% CI: 2.2–6.8); RdRP: 3.7 RNA copies/reaction (95% CI: 2.8–8.0).</p>\n \n <p>...</p>\n \n <p>In total, this testing yielded <strong>no false positive outcomes</strong>. In four individual test reactions, weak initial reactivity was seen but they were negative upon retesting with the same assay. These signals were not associated with any particular virus, and for each virus with which initial positive reactivity occurred, there were other samples that contained the same virus at a higher concentration but did not test positive. Given the results from the extensive technical qualification described above, it was concluded that this initial reactivity was not due to chemical instability of real-time PCR probes but most probably to handling issues caused by the rapid introduction of new diagnostic tests and controls during this evaluation study.\".</p>\n</blockquote></li>\n<li><p><a href=\"https://en.wikipedia.org/wiki/COVID-19_testing\" rel=\"nofollow noreferrer\">COVID-19 testing</a>:</p>\n\n<blockquote>\n <p>\"Testing for the <a href=\"https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndrome_coronavirus_2\" rel=\"nofollow noreferrer\">respiratory illness</a> named <a href=\"https://en.wikipedia.org/wiki/Coronavirus_disease_2019\" rel=\"nofollow noreferrer\">coronavirus disease 2019</a> (COVID-19) and the associated <a href=\"https://en.wikipedia.org/wiki/SARS-CoV-2\" rel=\"nofollow noreferrer\">SARS-CoV-2 virus</a> is possible with two main methods: <a href=\"https://en.wikipedia.org/wiki/Molecular_recognition\" rel=\"nofollow noreferrer\">molecular recognition</a> and <a href=\"https://en.wikipedia.org/wiki/Serology\" rel=\"nofollow noreferrer\">serology</a> testing.</p>\n \n <p>Molecular methods leverage <a href=\"https://en.wikipedia.org/wiki/Polymerase_chain_reaction\" rel=\"nofollow noreferrer\">polymerase chain reaction</a> (PCR) along with <a href=\"https://en.wikipedia.org/wiki/Nucleic_acid_tests\" rel=\"nofollow noreferrer\">nucleic acid tests</a>, and other advanced analytical techniques, to detect the genetic material of the virus using real-time <a href=\"https://en.wikipedia.org/wiki/Reverse_transcription_polymerase_chain_reaction\" rel=\"nofollow noreferrer\">reverse transcription polymerase chain reaction</a> for diagnostic purposes.</p>\n \n <p>Serology testing, leverages <a href=\"https://en.wikipedia.org/wiki/ELISA\" rel=\"nofollow noreferrer\">ELISA</a> antibody test kits to detect the presence of antibodies produced by the host <a href=\"https://en.wikipedia.org/wiki/Immune_system\" rel=\"nofollow noreferrer\">immune system</a> against the virus. </p>\n \n <p>...</p>\n \n <p>Serology antibody testing is being used both for surveillance and investigational purposes including, in China, confirmation of recovery only, while the molecular test methodologies are used to diagnosis active infections.\".</p>\n \n <p>\"There are several serology techniques that can be used depending on the antibodies being studied. These include: ELISA, agglutination, precipitation, complement-fixation, and fluorescent antibodies and more recently chemiluminescence.\".</p>\n</blockquote></li>\n</ul>\n", "score": 4 }, { "answer_id": 24246, "body": "<p>First off, it depends on which test - blood draw for antibodies (past infection), or saliva/nasal swab for current infection.</p>\n<p>Here is an easy-to-understand answer from <a href=\"https://www.health.harvard.edu/diseases-and-conditions/if-youve-been-exposed-to-the-coronavirus\" rel=\"nofollow noreferrer\">Harvard Heath</a>:</p>\n<blockquote>\n<p>&quot;If you get the nasal/throat swab or saliva test, you will get a false negative test result:</p>\n<ul>\n<li>100% of the time on the day you are exposed to the virus. (There are so few viral particles in your nose or saliva so soon after infection that the test cannot detect them.)</li>\n<li>About 40% of the time if you are tested four days after exposure to the virus.</li>\n<li>About 20% of the time if you develop symptoms and are tested three days after those symptoms started.\nThis possibility of a false negative test result is why anyone who has symptoms that could be due to COVID-19, or has been exposed to someone known to be infected, must isolate even if they test negative for coronavirus.&quot;</li>\n</ul>\n</blockquote>\n", "score": 2 } ]

[ "covid-19" ]

[ { "answer_id": 240, "body": "<p>In general any cellular material within the vitreous may cause eye floaters, for example red blood cells as a result of hemorrhage and white blood cells as a result of infection or inflammation. So cause of it should be always determine by a doctor (ophthalmologist). Abnormal eye floaters are associated with bleeding in the vitreous from diabetic retinopathy, retinal tears, retinal detachment or large degrees of nearsightedness. If floaters are accompanied by flashes of light or a loss of side vision, seek medical advice immediately.</p>\n\n<p>Most eye floaters decrease/reduce in size on their own due to absorption through the natural processes within the eye. The brain also adapts to the floaters, teaching the eyes to become less aware of them. With age almost everyone has it, but some are more aware than the others.</p>\n\n<p>There are no safe and proven methods to cure in both safe and effective way, however appropriate anti-inflammatory drugs or antibiotics prescribed by your doctor could reduce the number of white blood cells which are results of inflammation are common types of cellular material causing eye floaters. No other medications or eye drops have been proven effective in the treatment of eye floaters.</p>\n\n<p>The vitreous itself can also be surgically removed by <a href=\"http://en.wikipedia.org/wiki/Vitrectomy\" rel=\"noreferrer\">vitrectomy</a>. It removes the actual vitreous from the eye, eliminating the eye floaters in the process, but it also increase risk of retinal detachment or cataract, so surgery should only be used as a treatment for eye floaters in extreme cases. Some laser procedures are also used to get rid of floaters, but they also contain risks.</p>\n\n<hr>\n\n<p>Some health professionals believe that certain nutritional supplements and lifestyle (e.g. reducing stress) changes may help get rid of eye floaters as well as certain herbs, vitamins and odine-containing products have been touted as effective in decreasing eye floaters (none of these have been proven effective in clinical trials).</p>\n\n<p>These might include antioxidant vitamins, MSM eyedrops and hyaluronic acid to keep the eye hydrated (See: <a href=\"http://www.wikihow.com/Reduce-Floaters\" rel=\"noreferrer\">How to Reduce Floaters</a>), for example:</p>\n\n<ul>\n<li><p>Antioxidant vitamins (such as turmeric, wild rose hip, propolis concentrate and hawthorn berry) in concert with other vitamins, are proven to be effective in treating macular degeneration, but not in reducing floaters. (<a href=\"http://articles.chicagotribune.com/2012-05-30/health/sc-health-0530-eyesight-supplements-20120530_1_age-related-eye-disease-study-antioxidant-vitamins-beta-carotene-and-zinc\" rel=\"noreferrer\">source</a>)</p></li>\n<li><p>MSM eyedrops. MSM, or methylsulfonylmethane (dimethyl sulfone), is a widely-used nutritional supplement, most notably for arthritis. For uses other than arthritis, however, studies show only dubious results. (<a href=\"http://www.natural-remedies-review.com/msm.html\" rel=\"noreferrer\">source</a>)</p></li>\n<li><p>Ginko biloba has been proven effective in increasing ocular blood flow and is used by patients suffering from glaucoma. (<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10385132\" rel=\"noreferrer\">study</a>)</p></li>\n<li><p>Lysine is a vasodilator, which means that it widens blood vessels, particular in large veins. Lysine has proven effective in widening blood vessels in some areas, but not necessarily in the eyes. (<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8732492\" rel=\"noreferrer\">study</a>)</p></li>\n<li><p>Bilberry is used both for improving eyesight and for widening blood vessels (<a href=\"http://www.nlm.nih.gov/medlineplus/druginfo/natural/202.html\" rel=\"noreferrer\">source</a>). More tests are needed to investigate the efficacy of bilberry in treating floaters.</p></li>\n</ul>\n\n<p>Nutrients which are important in managing eye floaters according to <a href=\"http://www.naturaleyecare.com/eye-conditions/eye-floaters/\" rel=\"noreferrer\">NaturalEyeCare</a>:</p>\n\n<ul>\n<li><p>Hyaluronic acid</p>\n\n<blockquote>\n <p>Hyaluronic acid (hyaluronan) is a large molecule found in the vitreous gel which it is believed contributes to its gel-like quality and may also support related connective tissue. Elsewhere in the body it is found in the gel-like fluid that lubricates joints and it is a component of the tissue healing process. As we age, the amount of hyaluronan in the body decreases.</p>\n \n <p>Hyaluronic acid has been shown to be effective in helping eyes heal after cataract surgery. (<a href=\"http://www.natural-remedies-review.com/msm.html\" rel=\"noreferrer\">source</a>)</p>\n</blockquote></li>\n<li><p>Glucosame sulfate</p>\n\n<blockquote>\n <p>Glucosamine sulfate helps maintain connective tissue integrity. Some floaters are caused by disintegration of the lining of the vitreous sac. This nutrient may help slow down the natural aging effect on a weakening vitreous. Many people have noted an increase in floaters when they have joint disorders which may be related to chronic, systemic inflammation and its effect on eye health.</p>\n</blockquote></li>\n<li><p>Vitamin C</p>\n\n<blockquote>\n <p>Vitamin C is a powerful antioxidant that is essential for overall eye health. Since floaters are often the result of vitreous tears/detachments and/or clumping of the vitreous due to aging, vitamin C plays a role in blood and lymph circulation, waste elimination and supporting connective tissue. It may play a role in supporting the body in breaking down eye floaters. Learn more about the role of vitamin C in the body.</p>\n</blockquote></li>\n<li><p>L-methionine</p>\n\n<blockquote>\n <p>This amino acid can assist in removal of heavy metals and toxins that can contribute to eye disease. Methionine has a role in the body's synthesis of cysteine and taurine, two other important amino acids for vision health.</p>\n</blockquote></li>\n<li><p>Inositol</p>\n\n<blockquote>\n <p>The carbohydrate inositol plays a role in moderating levels of calcium in the cell membrane and within each cell, which in turn plays a role in protecting the vitreous.</p>\n</blockquote></li>\n<li><p>Calcium </p>\n\n<blockquote>\n <p>Calcium supports healthy connective tissue of the eye and throughout the body. Researchers have found that low levels of calcium (in proportion to phosphorus) is tied to increases in floaters.</p>\n</blockquote></li>\n<li><p>Zinc, Copper &amp; Chromium</p>\n\n<blockquote>\n <p>Zinc has some antioxidant characteristics. It plays a major role in bringing Vitamin A from the liver to the retina and helps Vitamin A create a protective pigment called melanin. Zinc also helps support the health of tiny capillaries in the eye, which are essential in nourishing the retina and related connective tissue. Zinc and copper, in balance, help support a proper acid balance in the body, which in turn helps may help avoid development of new floaters. Chromium may help limit nearsightedness, a risk factor for eye floaters. Chromium also has a role in sugar balance in the body.</p>\n</blockquote></li>\n</ul>\n\n<hr>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.medicinenet.com/eye_floaters/article.htm\" rel=\"noreferrer\">Eye Floaters</a> at Medicine Net</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Posterior_vitreous_detachment\" rel=\"noreferrer\">Posterior vitreous detachment (PVD)</a></li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11131410\" rel=\"noreferrer\">Pars plana vitrectomy for persistent, visually significant vitreous opacities.</a> (study)</li>\n</ul>\n", "score": 8 }, { "answer_id": 31, "body": "<p>The source does not explicitly tell the long-term story, but I presume that since those particles are actual matter inside your eye (due to the ageing process as your body slowly disseminates), then they would not dissolve with the time, nor leave the eye-ball. </p>\n\n<p>Logically, they might stick to the wall of an eye-ball or something similar. Nor is it likely that the new particles would occur very often. But that is just an educated guess based on the source (TED-Ed): <a href=\"https://www.youtube.com/watch?v=Y6e_m9iq-4Q\" rel=\"nofollow\">https://www.youtube.com/watch?v=Y6e_m9iq-4Q</a></p>\n", "score": 3 } ]

[ "eye", "ophthalmology", "aging" ]

[ { "answer_id": 249, "body": "<p>You have two main nervous systems when it comes to energy usage / conservation.</p>\n\n<ul>\n<li><p><strong>Sympathetic</strong></p>\n\n<ul>\n<li>Increased Heart Rate </li>\n<li>Dilation of bronchioles [increased intake /\nexhalation of air] </li>\n<li>Dilation of Pupils </li>\n<li><p>Vaso constriction in skin [tightening of blood vessels near skin]</p></li>\n<li><p>Vaso dilation in skeletal muscles [widening of blood vessels near\nmuscles]</p></li>\n<li>Slowing of peristalsis conversion of glycogen to glucose in liver\nsecretion of epinephrine and norephinephrine [ hormones to\nincrease heart rate]</li>\n</ul></li>\n<li><strong>Parasympathetic</strong>\n<ul>\n<li>Constriction of pupil</li>\n<li>Constriction of bronchioles</li>\n<li>Slowing of heart rate</li>\n<li>Increase secretion of digestive glands</li>\n</ul></li>\n</ul>\n\n<p><em>^{Tabers Cyclopedic Medical Dictionary (21)}</em></p>\n\n<p>When you decide to eat, the parasympatheic nervous system begins conserving energy so that more of it goes to digesting food and other bodily functions.</p>\n\n<p>When you decide to exercise, the sympathic nervous system begins expending energy so that you can do exercise x.</p>\n\n<p>In both of these, the other nervous system is reduced, permitting more energy to be given as needed.</p>\n\n<p>When you both consume food and exercise the body is placed in a tricky position. It can't say no to digesting food, it will begin to rot (gas anyone?) and it needs that food to generate more energy later on. But it can't say no to exercise, that could very realistically kill you in a survival situation.</p>\n\n<p>So it does a compromise, both will function at decreased levels.</p>\n\n<p>This doesn't mean you can't eat food while exercising. As otherwise mentioned, marathoners do consume food. But it's unlikely they will eat complex foods like fat or protein and go straight to simple foods like carbohydrates since it is easier for the body to break it down. Despite simple foods, energy must be used to digest so it makes exercising harder. But the benefit of the energy is more quickly greater then not consuming it. Consuming too much can override this though. ^{<a href=\"http://antranik.org/the-catabolism-of-fats-and-proteins-for-energy/\">1</a>} There aren't any long term marathoners I know of that eat a thanksgiving dinner prior and expect to make it very far.</p>\n", "score": 12 }, { "answer_id": 245, "body": "<p>It takes energy (and blood) to digest the food. So when you eat shortly before exercising, you need the energy at two places (digestion and muscles) and the muscles win.</p>\n\n<p>This does not mean it is bad to eat before (or during) exercise. Some exercises (like running a marathon) requires you to replenish the energy (and the food) but you can't eat anything. You need to time your consumption. (Heavy foods take longer to digest so the time gap needs to be longer). </p>\n\n<p>I have most of this information from a book on sport injuries. But I have found a <a href=\"http://dailyburn.com/life/health/pre-workout-fuel/\">reasonable reference</a>.</p>\n", "score": 5 }, { "answer_id": 370, "body": "<p>Your body needs time to digest (which depends on how much you've eaten) as it takes a lot of energy. Too much fat or protein can only slow down the movement of foods from the stomach making you feel uncomfortable^{<a href=\"http://www.nhs.uk/Livewell/Goodfood/Pages/Sport.aspx\" rel=\"nofollow noreferrer\">NHS</a>}. It's also important to be well hydrated when exercise, and when digesting food the water is important as part of the digestion process to break down the fat molecules, so you can be more easily dehydrated.</p>\n\n<p>During the digestion process, your body produces more <a href=\"http://en.wikipedia.org/wiki/Digestive_enzyme\" rel=\"nofollow noreferrer\">digestive enzymes</a> (stomach acid) and if you'd change your body position during the exercises, you put more pressure on your LES (<a href=\"http://en.wikipedia.org/wiki/Stomach\" rel=\"nofollow noreferrer\">lower esophageal sphincter</a>). In normal condition it holds the top of the stomach closed, however if you've a weak <a href=\"https://en.wikipedia.org/wiki/Sphincter\" rel=\"nofollow noreferrer\">sphincter</a> or you're pre-disposed to develop GERD (<a href=\"https://en.wikipedia.org/wiki/Sphincter\" rel=\"nofollow noreferrer\">acid reflux disease</a>), the changes in the barrier can cause stomach acids coming up from the stomach into the esophagus (see <a href=\"http://en.wikipedia.org/wiki/Gastroesophageal_reflux_disease\" rel=\"nofollow noreferrer\">reflux disease</a>).</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Heartburn\" rel=\"nofollow noreferrer\">Heartburn</a> is usually associated with <a href=\"http://en.wikipedia.org/wiki/Regurgitation_(digestion)\" rel=\"nofollow noreferrer\">regurgitation</a> of gastric acid (gastric reflux) which is the major symptom of gastroesophageal reflux disease (GERD). Especially after eating spices, high fat or high acid food.</p>\n\n<p>If you're young and healthy, it is fine, but it all depends on your health condition (GERD predispositions and risk of disease).</p>\n\n<p>Therefore if you're planning an exercise, consider limit your meal or aim for a snack.</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"https://health.stackexchange.com/q/408/114\">Is eating one's dinner right before going to sleep bad for health?</a></li>\n<li><a href=\"https://health.stackexchange.com/q/155/114\">What are the health tradeoffs between eating while standing vs. sitting vs. in reclining position?</a></li>\n</ul>\n", "score": 0 } ]

[ "nutrition", "exercise" ]

[ { "answer_id": 465, "body": "<p>This is a hot topic, and I don’t think there is a firm consensus in the child psychiatry world about the answer. I think a good summary of the literature would leave you with: </p>\n\n<blockquote>\n <p>X, Y, and Z studies showed an association; Χ, Ψ, and Ω studies showed no association.</p>\n</blockquote>\n\n<p>Excellent. Ιn lieu of that, I'm going to use one study to illustrate a couple methodological points to show you <em>why</em> this answer is difficult to know. My goal is to help the reader develop a skeptical eye when research of this type is presented.</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21779528/\">One study</a> used teacher questionnaires about hyperactivity symptoms and student questionnaires about dietary habits to see if a relationship existed between high sugar intake and hyperactivity. They found that children were at statistically higher risk for ADHD if they consumed: </p>\n\n<ul>\n<li>less sugar from fruit snacks </li>\n<li>low Vitamin C </li>\n</ul>\n\n<p>However, the total simple sugar intake did <em>not</em> correlate with hyperactivity symptoms.</p>\n\n<p><strong>This makes very little sense.</strong> Why should fruit snacks be different from other sugar, and where did Vitamin C come from?</p>\n\n<ol>\n<li><p><a href=\"http://en.wikipedia.org/wiki/Errors_and_residuals_in_statistics\"><strong>Statistical noise</strong></a>. Data interpretation relies on a <a href=\"https://books.google.com/books?id=jHe6dsZLGcMC&amp;pg=PA116&amp;dq=david+katz+signal+to+noise+ratio&amp;hl=en&amp;sa=X&amp;ei=KDopVbTpNsHHsQSs5oHgCA&amp;ved=0CCUQ6AEwAQ#v=onepage&amp;q=david%20katz%20signal%20to%20noise%20ratio&amp;f=false\">ratio of signal:noise</a> to find the signal (in this case, an association). A 5-second brainstorm will bring to mind dozens of unrelated (to usual dietary patterns) topics that may affect what students write down on questionnaires: literacy, gender, upbringing, vocabulary, organization, memory, day-of-the-week, recent holidays, who won the Red Sox game, etc. etc. etc. Some of these may reflect recent dietary patterns that skew the memory of <em>usual</em> dietary patterns; others simply affect the accuracy of report. One could generate an equally diverse list of factors that may affect teacher reports. Either way, the result is the same: a noisy signal.</p></li>\n<li><p><a href=\"http://www.biostathandbook.com/confounding.html\"><strong>Confounding</strong></a>. A <em>confound</em> exists when an extraneous factor exists that correlates with both the independent (dietary report) and the dependent (inattentiveness) variable. In this case, one could imagine that students who tend to be careless about reporting might also be those displaying symptoms of hyperactivity (which tends to run with inattentiveness). It’s not obvious whether that would lead to <em>under</em> or <em>over</em> reporting of sugar intake. </p>\n\n<p>Generally, obvious confounders can be adjusted for statistically (here, I don't see that they did much of that, although they did do separate analyses for boys vs girls). However, no amount of math can adjust for factors that aren’t measured. There was no “carelessness independent of hyperactivity” score obtained here, and we couldn’t expect it &mdash; it’s a basically unknowable parameter. Certain confounders are inherent to the methodology. Math never fixes this.</p></li>\n<li><p><a href=\"http://www.biostathandbook.com/multiplecomparisons.html\"><strong>Multiple comparisons</strong></a>. The basic principle is: if you look at enough factors, <em>something</em> is going to be statistically associated with something else <strong>for reasons that have nothing to do with reality.</strong> That’s because we define statistical significance as a result that would occur by chance &lt;5% of the time. If you run 20 tests, you have a good chance of coming up with one of them that appears to be positive simply by chance. In data that has a low signal:noise ratio (see #1), this problem is all the more apparent. This is something to think about when unexpected results pop up from a study that was designed to look at something completely different. Vitamin C??!</p></li>\n</ol>\n\n<p>Please note: this is not meant to be (primarily) a critique of this particular study. My goals here were to help the reader understand: </p>\n\n<ul>\n<li>Why do I find different answers to this question every time I do a google search? </li>\n<li>How should we think critically about epidemiological data presented on Health.SE?</li>\n</ul>\n\n<hr>\n\n<p>_{\nKim, Y. Chang, H. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21779528/\"><em>Correlation between attention deficit hyperactivity disorder and sugar consumption, quality of diet, and dietary behavior in school children.</em></a> Nutr Res Pract. 2011 Jun;5(3):236-45.\n}</p>\n", "score": 17 } ]

[ "sugar", "pediatrics", "hyperactivity-hyperactive" ]

[ { "answer_id": 525, "body": "<p>As far as I am aware, the immune system does not have a \"boosted\" state. There is a medical doctor, Mark Crislip, who wrote a post about this on <a href=\"https://www.sciencebasedmedicine.org/boost-your-immune-system/\">Science-based medicine</a>, and I'll cite here the most pertinent lines. Even though he takes a very one-sided position, I personally find his writing convincing, and the whole article is worth reading. It makes many more points I'm leaving out here. </p>\n\n<blockquote>\n <p>What does that mean: boost the immune system? Most people apparently think that the immune system is like a muscle, and by working it, giving it supplements and vitamins, the immune system will become stronger. [...] The other popular phrase is “support”. </p>\n \n <p>The immune system, if you are otherwise healthy, cannot be boosted</p>\n \n <p>If you google the phrase “boost the immune system” you will find over 288,000 pages that give advice on how to give that old immune system a lift. Curiously, a Pubmed search with the same phase yields 1100 references, most concerning vaccination. If you Pubmed ‘enhanced immune system’ you get 41,000 references mostly concerning immunology. None of the references concern taking a normal person and making the immune system work better than its baseline to prevent or treat infection</p>\n \n <p>Those who say that that their product, for example probiotics, boost the immune system, point to studies such as these that show that in response to bacteria, cells of the immune system are activated [...] They call it boosting. I call it the inflammatory response.</p>\n</blockquote>\n\n<p>The article then goes on to cite several studies which found that being constantly subject to inflammatory response has several ill effects on health. </p>\n\n<p>He does admit that you need to be otherwise healthy (by following what he calls \"kindergarten advice\" of eating healthy, getting enough sleep and exercise) to have an immune system working at its baseline. So maybe you could say that, if your immune system is running at reduced \"strength\" due to increased stress, you could \"boost\" it by reducing your stressors. But this does not mean that, if you are stressed and consume probiotics or other presumably boosting products, you'll somehow get to the baseline. Also, I share Crislip's view here: it would be misleading to call it boosting when it's simply being returned to its standard state. </p>\n\n<hr>\n\n<p>There is another possible meaning of \"boost the immune system\" which does have a basis in fact. If you get a vaccine against a certain disease, you are not exposed to a constant inflammatory response, but you will be able to fight off this one disease better. I was not going to post it here, as this is not the sense usually meant in marketing materials. But the first tip in the first link you gave said \"get a flu vaccine\", so I thought it's worth mentioning. It will not have any effect on other aspects of your health. </p>\n", "score": 14 }, { "answer_id": 524, "body": "<h2>How to boost immune system</h2>\n\n<h3>Sleep boosts immunity</h3>\n\n<p>Sleep is very important for our health and lack of sleep can affect our whole immune system.</p>\n\n<p>That's because our body's biological clock is set for 24-hour rhythm and certain periods of light and darkness (<a href=\"https://en.wikipedia.org/wiki/Circadian_rhythm\" rel=\"nofollow noreferrer\">a circadian rhythm</a>), and when it's thrown off, so is the immune system. </p>\n\n<p><img src=\"https://i.stack.imgur.com/Wkoqt.png\" alt=\"Biological clock human\"></p>\n\n<p>^{Image credits: <a href=\"https://en.wikipedia.org/wiki/Circadian_rhythm\" rel=\"nofollow noreferrer\">A circadian rhythm</a> at Wikipedia}</p>\n\n<p>Regular poor sleep or prolonged lack of sleep can disrupt your body's natural immune system and can lead to many illnesses such as infections (such as cold/flu^{<a href=\"http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/immune-system-lack-of-sleep\" rel=\"nofollow noreferrer\">webmd</a>}) and increasing risk of serious medical conditions such as obesity, heart disease, diabetes as well as it can shortens your life expectancy.</p>\n\n<p>So every time when you catch cold and flu, you could blame your bedtime.</p>\n\n<p>Therefore when planning your activities and rest, you should consider around 8 hours of good quality sleep a night to function properly (some of us need more or less time).</p>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/Livewell/tiredness-and-fatigue/Pages/lack-of-sleep-health-risks.aspx\" rel=\"nofollow noreferrer\">Why lack of sleep is bad for your health</a> at NHS}</p>\n\n<p>If you have a disturbed sleep patterns you can have [a power nap] during the day when you get tired, it helps a lot. The benefits of napping could be best obtained by training the body and mind to awaken after a short nap. Naps of fewer than 30 minutes restore wakefulness and promotes performance and learning^{<a href=\"https://en.wikipedia.org/wiki/Circadian_rhythm\" rel=\"nofollow noreferrer\">2007</a>, <a href=\"http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/immune-system-lack-of-sleep\" rel=\"nofollow noreferrer\">2008</a>}.</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.huffingtonpost.com/2013/11/08/sleep-immune-system-body-clock_n_4235943.html\" rel=\"nofollow noreferrer\">ScienceNOW: Sleep's Effects On Your Immune System Revealed In New 'Body Clock' Study</a></li>\n<li><a href=\"https://health.stackexchange.com/q/506/114\">How to avoid fatigue if I foresee irregular sleeping time?</a></li>\n</ul>\n\n<h3>Reduce stress to boost energy</h3>\n\n<p>Stress uses a lot of energy and introducing relaxing activities into your day can improve your energy. This can include deep muscle relaxation, physical exercises (yoga, tai chi or vigorous physical activity at gym), relaxed breathing (yoga, medication), spa, listen to music or sound effects, spending some time with friends and anything else that relaxes you.</p>\n\n<p>Relaxation can help you to relieve symptoms of stress and calm you down</p>\n\n<p>See: <a href=\"http://www.nhs.uk/Conditions/stress-anxiety-depression/Pages/ways-relieve-stress.aspx\" rel=\"nofollow noreferrer\">Relaxation tips to relieve stress</a> at NHS</p>\n\n<h3><a href=\"https://en.wikipedia.org/wiki/Nutrition\" rel=\"nofollow noreferrer\">Nutrition</a> and <a href=\"https://en.wikipedia.org/wiki/Diet_(nutrition)\" rel=\"nofollow noreferrer\">diet</a></h3>\n\n<p>Our immune system requires ingestion and absorption of vitamins, minerals, and food energy in the form of carbohydrates, proteins, and fats. </p>\n\n<p>Foods rich in certain fatty acids (such as <a href=\"https://en.wikipedia.org/wiki/Conjugated_linoleic_acid\" rel=\"nofollow noreferrer\">conjugated linoleic acid</a>, catalpic acid, eleostearic acid and <a href=\"https://en.wikipedia.org/wiki/Punicic_acid\" rel=\"nofollow noreferrer\">punicic acid</a>) may boost your healthy immune system by providing additional energy.</p>\n\n<p>The amount and type of carbohydrates consumed is also important so intake isn't too much (<a href=\"https://en.wikipedia.org/wiki/Overnutrition\" rel=\"nofollow noreferrer\">overnutrition</a>) or too less (<a href=\"https://en.wikipedia.org/wiki/Malnutrition\" rel=\"nofollow noreferrer\">malnutrition</a>).</p>\n\n<h3>Drink less alcohol</h3>\n\n<p>Regular drinking can affect your immune system and heavy drinkers tend to catch more infectious diseases.</p>\n\n<p>If you cut down on alcohol before bedtime, you'll get a better night's rest and have more energy next day.</p>\n\n<p>See:</p>\n\n<ul>\n<li><a href=\"http://www.nhs.uk/Livewell/alcohol/Pages/Tipsoncuttingdown.aspx\" rel=\"nofollow noreferrer\">Tips on cutting down</a> at NHS</li>\n<li><a href=\"https://en.wikipedia.org/wiki/Long-term_effects_of_alcohol_consumption#Immune_system\" rel=\"nofollow noreferrer\">Long-term effects of alcohol consumption - Immune system</a> at Wikipedia</li>\n</ul>\n\n<h3>Cut out caffeine</h3>\n\n<p>If you find that not consuming caffeine gives you headaches, you should cut down on the amount of caffeine.</p>\n\n<p>The Royal College of Psychiatrists recommends that anyone feeling tired should cut out caffeine.</p>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/Livewell/tiredness-and-fatigue/Pages/self-help-energy-tips.aspx\" rel=\"nofollow noreferrer\">Self-help tips to fight fatigue</a> at NHS}</p>\n\n<h3>Drink more water for better energy</h3>\n\n<p>Sometimes we feel tired, because we're mildly dehydrated, so glass of water can help (especially after exercise).</p>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/Livewell/tiredness-and-fatigue/Pages/self-help-energy-tips.aspx\" rel=\"nofollow noreferrer\">Self-help tips to fight fatigue</a> at NHS}</p>\n", "score": 5 } ]

[ "nutrition", "immune-system" ]

[ { "answer_id": 741, "body": "<p>In premenopausal women, the risk of developing atherosclerosis is <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10364080\">half that of men</a>. In 1991, Sullivan proposed the iron hypothesis which attributed this decreased risk to premenopausal women's lower blood iron levels, and suggested that blood donation may reduce the risk of developing atherosclerosis.</p>\n\n<p>The validity of the hypothesis is still an open question and presenting an analysis of current evidence would be long and inappropriate. </p>\n\n<p>However honing in on the question of randomized clinical trials on the effects of blood donation, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17299195\">a first randomized clinical trial</a> (FeAST) was conducted by Dr. Zacharski et al. in 2007, examining the effects of phlebotomy on the risk of cardiovascular disease in patients with peripheral arterial disease (PAD). The study found that a reduction in body iron stores did not significantly decrease all-cause mortality or death plus nonfatal myocardial infarction and stroke.</p>\n\n<p>This FeAST trial has several limitations one primarily being that the trial focused on secondary prevention in patients who had existing PAD, rather than focusing on primary prevention as postulated by the iron hypothesis. </p>\n\n<p>Therefore further research is still required before a conclusion can be reached on the validity of the iron hypothesis.</p>\n", "score": 10 } ]

[ "cardiovascular-disease", "blood-donation", "medical-myths", "hematology" ]

[ { "answer_id": 4056, "body": "<p>It seems to me that you are looking for solid risk numbers, which I am afraid might not be available. This is just a summary of the basic facts that play into this likelihood. </p>\n\n<blockquote>\n <p>For example, what is the likelihood when the partner is asymptomatic vs symptomatic</p>\n</blockquote>\n\n<p>So-called \"asymptomatic shedding\", when the virus can be transmitted despite the carrier not showing any sores, is very common in both herpes types. </p>\n\n<p>A good article on this is <a href=\"http://m.jid.oxfordjournals.org/content/198/8/1098.full\" rel=\"noreferrer\">Asymptomatic Shedding of Herpes Simplex Virus 1 and 2: Implications for Prevention of Transmission</a>. It gives an overview over several studies, for example one where 144 heterosexual couples where only one partner was infected were tracked. </p>\n\n<blockquote>\n <p>Transmission occurred in 14 (9.7%) of the couples, including 13 in which diaries were maintained during the period when transmission occurred. Although 4 couples (31%) reported sexual contact during the prodrome (1 case) or within hours before lesions were first noted by the symptomatic partner (3 cases), in 9 cases (69%) transmission resulted from sexual contact when the source partner reported no symptoms or lesions</p>\n</blockquote>\n\n<p>PCR studies found that over 80 percent of people showed asymptomatic shedding, on around 20 percent of the days. </p>\n\n<p>So the likelihood probably wouldn't dramatically decrease just because the infected partner is asymptomatic. </p>\n\n<p>HSV1 in the genital region <a href=\"http://jid.oxfordjournals.org/content/181/4/1454.short\" rel=\"noreferrer\">is becoming</a> <a href=\"http://journals.lww.com/stdjournal/Fulltext/2003/10000/Is_Herpes_Simplex_Virus_Type_1__HSV_1__Now_More.13.aspx\" rel=\"noreferrer\">more common</a>. It is responsible for between 20 and 40 percent of genital herpes. Part of that increase might be from oral sex, but there is no single likelihood figure that can be attributed to a single instance of unprotected oral sex, at least that I can find. </p>\n\n<blockquote>\n <p>what is the likelihood if the person contracting it has already been exposed to oral HSV1 as a child?</p>\n</blockquote>\n\n<p>It's possible. Again, we can't really attach a number to that risk. <a href=\"http://onlinelibrary.wiley.com/doi/10.1002/jmv.20132/abstract;jsessionid=B906EF4B7C7AD8481B571773C1ED1838.f03t02\" rel=\"noreferrer\">Even people with genital HSV-1 can be infected with another strain of HSV-1 genitally, afterwards being infected twice.</a> </p>\n\n<blockquote>\n <p>Whereas the sequential HSV-1 isolates in 11 of the 13 patients studied had the same genotypes, the sequential isolates of 2 patients showed a different genotype. The data suggest that HSV-1-induced recurrent genital herpes can be associated with genital reinfection with an exogenous HSV-1 strain.</p>\n</blockquote>\n\n<p>Small sample size, but we only care that it's possible at all here. </p>\n\n<blockquote>\n <p>If genital HSV1 is contracted, how long does it usually take to find out? (when would symptoms start to appear)</p>\n</blockquote>\n\n<p>This varies, not just by a lot of time, but it even varies whether people <em>ever</em> show symptoms. The <a href=\"http://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm\" rel=\"noreferrer\">incubation period is a few days</a>, but around <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10547406\" rel=\"noreferrer\">one third</a> of patients may not show symptoms at all. Even more may not recognize them as a herpes infection. HSV-1 also <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804398/\" rel=\"noreferrer\">recurs less often</a> after the first outbreak. This leads to a lot of people not even knowing they are infected. Combined with the asymptomatic shedding of the virus, this leads to <a href=\"http://www.ncbi.nlm.nih.gov/books/NBK47447/\" rel=\"noreferrer\">HSV being a rather prevalent disease</a>. And not even serological testing is <a href=\"http://www.cdc.gov/std/herpes/stdfact-herpes-detailed.htm\" rel=\"noreferrer\">over 90 percent certain to detect an infection</a>. The CDC does recommend that patients who have probably been exposed should be tested, though. </p>\n\n<p>(The part of this answer about asymptomatic shedding is taken from an answer written by me to another question <a href=\"https://health.stackexchange.com/questions/1924/what-stds-can-be-transmitted-if-both-parties-have-no-open-sores-cuts\">What STDs can be transmitted if both parties have no open sores/cuts</a> ) </p>\n", "score": 9 } ]

[ "disease-transmission", "herpes", "sti" ]

[ { "answer_id": 23508, "body": "<p>Your question contains a lot of misconceptions.</p>\n\n<ul>\n<li>A cure is definitely possible</li>\n<li>A cure could be found, proved, and proved safe, more quickly than a vaccine</li>\n<li>People and firms that could be working on cures are choosing to work on vaccines</li>\n</ul>\n\n<p>None of these are correct. Most virus-caused diseases have no cure: colds, Zika, Dengue, and so on. A tiny handful have treatments that can ease the course of the disease: you've heard of Tamiflu and so on. And some can be actually cured with medication. So the first assumption, that a cure exists to be found, is not a sure thing by any means, and is actually quite unlikely.</p>\n\n<p>Then there is the matter of side effects, unintended consequences, and so on. We are pretty familiar with vaccinations by now. We know how to test that a vaccine doesn't cause other problems. But a cure often can have really bad effects. A drug that is supposed to lower your [blood pressure, heart rate, blood sugar, whatever] or raise your [immune response, whatever] might raise or lower it too much. It might cure one thing but give you a stroke or a heart attack. The immunotherapy that cured my 3-months-to-live melanoma also wiped out my thyroid and nearly killed me with a skin reaction. [I am fine with that trade, but the point is treatments can and do kill people. We only use them if the curing outweighs what the side effects do.] Cures have to be tested to understand all of these possibilities. In most cases we want to know the long term reactions -- and that means giving the drug and monitoring and studying for months or more. Plus, we give treatments to sick people, but vaccines to healthy people, so the side effects are even more of a big deal for a treatment.</p>\n\n<p>And finally, the money and teams to work on a vaccine are entirely different than the money and teams who work on cures. So work is underway on cures too. It hasn't been set aside to focus on vaccines.</p>\n\n<p>What you're observing is that everyone predicts a vaccine will come more quickly. It's a better understood area (we have vaccines for tons of viruses, but cures for very few) with less concern about hurting or killing the people we give it to. It's most likely the vaccine teams will succeed before the cure teams do. But it's not because there isn't any work happening on possible cures.</p>\n", "score": 62 }, { "answer_id": 23510, "body": "<p>Drugs are typically <a href=\"https://en.wikipedia.org/wiki/Small_molecule\" rel=\"noreferrer\">small molecules</a> that interfere with some chemical process in the disease causing microbe, and therein lies the rub. Bacteria, fungi, protozoa, worms, etc. are sustained by their own complex systems of chemical reactions, largely independent of chemical systems that sustain us. That makes it easier to find a chemical that attacks something in the microbe's chemistry, but doesn't affect our own chemistry (much). <a href=\"https://en.wikipedia.org/wiki/Penicillin\" rel=\"noreferrer\">Penicillin</a> for example, targets an enzyme bacteria use to maintain their cell walls. Our own cells don't have cell walls in the same way bacteria do, and we don't use that enzyme, so a drug that blocks that enzyme in bacteria may cripple the bacteria without having (much) of an effect on our own cells.</p>\n\n<p>Viruses on the other hand, are really just a bit of DNA or RNA wrapped in a coat of sugars, proteins, and fats. They don't have any life processes of their own. They simply piggy-back and subvert our own chemical systems. That means any drug that targets a chemical process used by the virus is likely to have bad side effects on the patient too. In some cases it is possible to create an <a href=\"https://en.wikipedia.org/wiki/Antiviral_drug#Transcription\" rel=\"noreferrer\">anti-viral</a> drug that attacks a protein unique (or mostly unique) to the virus. The problem is that this is a much narrower range of possible targets, and it tends to be specific to a single virus. Drugs like penicillin often work on whole families of bacteria. This is what makes finding a drug that \"cures\" viral diseases so hard.</p>\n\n<p>However, living creatures have had to defend themselves against viruses for billions of years, so we've evolved sophisticated internal defenses against them. Even <a href=\"https://en.wikipedia.org/wiki/CRISPR\" rel=\"noreferrer\">bacteria have a sort of immune system against viruses</a>. When you are infected with a virus your body begins a race to mount an effective immune response before the virus does severe or even fatal damage to your body. Vaccines allow your body to begin mounting an immune response before you are actually exposed to the virus. Then if you are eventually exposed your immune system is able to shut the virus down much more quickly. Getting a workable vaccine is still tricky though, because you have to find substances that starts an immune response specific to the target virus in most people, but that doesn't also kick the immune system into an over reaction that itself can be very dangerous.</p>\n", "score": 23 }, { "answer_id": 23514, "body": "<p>I don't believe we have the data to say that vaccines will be deployed earlier than an effective treatment.</p>\n\n<p>Vaccine technology is old technology and the go to for most infectious diseases as there is a desire to prevent preventable illness. However, HIV was discovered in 1984 but we still <a href=\"https://www.healthline.com/health/hiv-aids/vaccine-how-close-are-we\" rel=\"noreferrer\">don't have a vaccine against it</a> though we have effective treatments. Some of the problems with a vaccine for HIV is that it's not a respiratory virus, and it mutates rapidly.</p>\n\n<p>The SARS epidemic was in 2003 and we still also don't have a vaccine for that, and it's unclear if the new <a href=\"https://www.modernatx.com/modernas-work-potential-vaccine-against-covid-19\" rel=\"noreferrer\">mRNA vaccines for COVID-19</a> will be effective or not as there has not been one deployed successfully before.</p>\n\n<p>Most of our drugs used in treatment are small molecules but many of our modern biological drugs are synthetic humanised antibodies, and there is a lot of experience in developing such treatments in diseases such as Rheumatoid Arthritis, and Axial spondyloarthropathies.</p>\n\n<p>To develop such antibodies to fight COVID-19 an animal (mouse) can be infected with SARS-CoV-2 and the subsequent antibodies are screened for effectiveness. Those most promising are humanised and then further developed for testing. Celltrion are using antibodies taken from recovered Korean patients.</p>\n\n<blockquote>\n <p>Through a partnership with the Korea Centers for Disease Control and Prevention (KCDC), Celltrion initially identified and secured 300 different types of antibodies that bind to the SARS-CoV-2 antigen. These were then screened based on their ability to bind to the virus Spike (S) protein. Celltrion was then able to capture a total of 38 potent neutralising antibodies, of which, 14 were identified as most potent against SARS-CoV-2.</p>\n</blockquote>\n\n<p>...</p>\n\n<blockquote>\n <p>Ki-Sung Kwon, Head of R&amp;D Unit at Celltrion said: “We are bringing our full resources and expertise to overcome this global health crisis and are glad to have identified these antibodies sooner than previously expected. These antibodies can recognise multiple epitopes, thus increasing the probability of neutralisation against viral mutations. Given the expedited development process of our antiviral antibody treatment, we anticipate moving to first-in-human clinical trials in July. We are also on track with the development of a ‘super antibody’ or ‘an antibody cocktail’ and the launch of a rapid diagnostic kit in the summer of this year.”</p>\n</blockquote>\n\n<p>These would be expected to work like naturally developed antibodies that develop during the adaptive immune response to fight the infection.</p>\n\n<p><a href=\"https://www.drugtargetreview.com/news/60206/celltrion-selects-14-lead-monoclonal-antibodies-for-covid-19-treatment/\" rel=\"noreferrer\">https://www.drugtargetreview.com/news/60206/celltrion-selects-14-lead-monoclonal-antibodies-for-covid-19-treatment/</a></p>\n", "score": 7 } ]

[ "covid-19", "vaccination", "coronavirus" ]

[ { "answer_id": 82, "body": "<p>Overloading on vitamin C won't cause death. At around 1000 mg, you will probably have nausea, diarrhea, and stomach aches. 2000 mg is the daily limit, and if you get that high, you will experience more severe side-affects such as severe headaches, vomiting, heartburn, insomnia, and even kidney stones. You probably shouldn't have that much vitamin C, so if you have to take multiple 1000 mg doses everyday, you should talk to your doctor.</p>\n\n<p>In conclusion, taking that much vitamin C is not necessarily \"dangerous\", but it can lead to major discomfort and could possible put you in the hospital.</p>\n\n<hr>\n\n<p>^{<a href=\"http://www.medicaldaily.com/vitamin-overdose-taking-too-many-vitamins-can-be-bad-your-health-how-many-would-it-315426\" rel=\"noreferrer\">Vitamin Overdose: Taking Too Many Vitamins Can Be Bad For Your Health, But How Many Would It Take To Kill You?</a>}</p>\n", "score": 10 }, { "answer_id": 227, "body": "<p>Vitamin C (ascorbic acid - an antioxidant and reducing agent) is water soluble (so dietary excesses not absorbed), and excesses in the blood rapidly excreted in the urine. It exhibits remarkably low toxicity , however LD₅₀ in humans remains unknown given lack of any accidental or intentional poisoning death data.</p>\n\n<p>Government recommended intake:</p>\n\n<ul>\n<li><p>United States vitamin C dose recommendations:</p>\n\n<ul>\n<li>Recommended Dietary Allowance (adult male): 90 mg per day</li>\n<li>Recommended Dietary Allowance (adult female): 75 mg per day</li>\n<li>Tolerable Upper Intake Level (adult male): 2,000 mg per day</li>\n<li>Tolerable Upper Intake Level (adult female): 2,000 mg per day</li>\n</ul></li>\n<li>40 milligrams per day or 280 milligrams per week taken all at once: the United Kingdom's Food Standards Agency,</li>\n<li>45 milligrams per day 300 milligrams per week: the World Health Organization,</li>\n<li>80 milligrams per day: the European Commission's Council on nutrition labeling,</li>\n<li>90 mg/day (males) and 75 mg/day (females): Health Canada 2007,</li>\n<li>60–95 milligrams per day: United States' National Academy of Sciences,</li>\n<li>100 milligrams per day: Japan's National Institute of Health and Nutrition, however the NIHN did not set a Tolerable Upper Intake Level.</li>\n</ul>\n\n<p>Based on US upper level recommendations taking up to 1g per day is still fine, however it depends on your body tolerance and previous intake (as for some 5-10g could be still normal), especially if your body needs it for optimum health and to meet stresses or infections. Although the body's maximal store of vitamin C is largely determined by the renal threshold for blood.</p>\n\n<p>However if you exceed the upper limits of your body/bowel tolerance, in general any drug overdose is dangerous causing some side effects. Relatively large doses of ascorbic acid may cause indigestion, particularly when taken on an empty stomach and it can case diarrhoea. In one trial in 1936 (6g doses) toxic manifestations were observed in 5/29 adults and 4/93. Symptoms of Vitamin C overdose could include: skin rashes, nausea, vomiting, diarrhoea, facial flushing, headache, fatigue and disturbed sleep. As well as itchy skin (prurutis), dizziness and abdominal pain.</p>\n\n<p>It's usually advised to take smaller doses more frequently (e.g. ever hour), than larger doses in short amount of time in order to simulate endogenous production and increase your tolerance threshold. On the other hand your body would \"learn\" daily intake and it will expect similar doses on daily basis.</p>\n\n<p>Source: <a href=\"http://en.wikipedia.org/wiki/Vitamin_C\">Vitamin C</a></p>\n", "score": 10 }, { "answer_id": 96, "body": "<p>There are two important types of vitamins.</p>\n<p><strong>Fat soluble and Water Soluble.</strong></p>\n<p>Your body will store fat soluble vitamins but will discard excess water soluble vitamins in your urine. Because of this fat soluble vitamins carry a greater risk of toxicity while water soluble carry a greater risk of deficiency.</p>\n<p>Some examples of fat soluble <a href=\"http://www.ext.colostate.edu/pubs/foodnut/09315.html\" rel=\"noreferrer\">¹</a>\n<strong>A, D, E, K</strong></p>\n<p>and water soluble <a href=\"http://www.ext.colostate.edu/pubs/foodnut/09312.html\" rel=\"noreferrer\">²</a>\n<strong>B, C</strong></p>\n<p>You're fine with taking 1k of C everyday but it's unlikely to benefit you anymore once the body absorbs the 90mg it needs. Splitting a pill up into quarters (250mg) and consuming it with food (to increase chance of absorption) could work too.</p>\n<p>As for the dangerous part, yes. Despite what it may seem, more does not equal better. Balance and moderation is key. Anything is dangerous if overdosed, including water, oxygen, or ____</p>\n", "score": 6 }, { "answer_id": 1857, "body": "<p>While taking 1 gram or even more may not be acutely toxic as pointed out in the other answers, you should consider the question of why humans or other animals have not evolved to rid themselves of free radicals to the same degree as when one takes 1 gram or more of vitamin C. So, one can question if the naive picture of free radicals is actually correct, some recent research results suggest it may not be, <a href=\"http://ajcn.nutrition.org/content/87/1/142.full\" rel=\"nofollow noreferrer\">see e.g. here</a>:</p>\n\n<blockquote>\n <p>It is important to consider that free radicals are not always damaging to cells; in many cases, they serve as signals to adapt muscle cells to exercise via modulation of gene expression (9, 33). We have found that training causes an increase in 2 major antioxidant enzymes (Mn-SOD and GPx) in skeletal muscle. We were surprised to see that vitamin C prevents these beneficial effects of training. On the basis of the paradigm that enzymatic antioxidant systems such as Mn-SOD and GPx provide a first-line defense against ROS, it is expected that exercise may induce these protective mechanisms. Moderate exercise increases life span and decreases disability in rats (12) and humans (15). We report here that exercise training causes an increase in the expression of antioxidant enzymes, which is prevented by the administration of vitamin C.</p>\n</blockquote>\n\n<p>So, it is likely harmful and you should not use it. You can also take this perspective. We don't know all the relevant facts about free radicals, the way the human body gets rid of them, all the self repair mechanisms that the body does in addition to removing the free radicals, any use of free radicals in the immune system etc. etc. The simplistic idea to just flood the body with vitamin C is not based on a deep understanding of how the body actually works. The relevant mechanisms have evolved over more than 600 million years.</p>\n\n<p>Now, we know that vitamin C is produced by animals themselves who don't get it in their diet. Only when the diet contains sufficient amounts of vitamin C will the production of vitamin C have stopped. But this implies that more vitamin C is not better, because otherwise our bodies would just produce vitamin C itself in addition to what we get from food. In fact, the more we get from food the harder the body will work to remove it, but that takes a bit of time and with 1 gram per day you are going to get an equilibrium situation where there is just too much vitamin C in the body.</p>\n\n<p>Any theoretical argument why 1 gram per day is good should be based on a deep knowledge of the relevant facts which has never been presented. To the contrary, there are only good arguments why it is harmful (in the sense of not optimal for health). But of course, one can always do clinical trials, but those that have been conducted point to harmful effects consistent with the theoretical arguments.</p>\n", "score": 0 } ]

[ "nutrition", "micronutrients" ]

[ { "answer_id": 145, "body": "<p>The color, odor and consistency of urine can be differ and can reveal what you've been eating, how much drinking and what diseases you have, so change of the color is usually something completely normal. All substances circulating in your body (including bacteria, yeast, excess protein/sugar can make their way there. It's an important part of your body's disposal process and it's useful tool of diagnosis.</p>\n\n<p>Tomas Griebling, MD, MPH (vice chair of the urology department at the University of Kansas) says:</p>\n\n<blockquote>\n <p>From a historical view, urinalysis was one of the original windows into what's happening in the body.</p>\n</blockquote>\n\n<p>Anthony Smith, MD (professor and chief of urology at the University of New Mexico) says:</p>\n\n<blockquote>\n <p>The urine is there primarily to get rid of toxins or things that would otherwise build up in the body that would be bad for the body.</p>\n</blockquote>\n\n<hr>\n\n<p>Urine gets it color from the <a href=\"http://en.wikipedia.org/wiki/Urobilin\" rel=\"noreferrer\">urochrome pigment</a> and it ranges between light straw/yellow and dark/deep amber (honey). Darker color is normally when you're urinating first in the morning (this indicates your liver was busy at night to get rid of toxins). During day or evening can indicate <a href=\"http://en.wikipedia.org/wiki/Dehydration\" rel=\"noreferrer\">dehydration</a>, so you should drink more water.</p>\n\n<p>These are some of the medicines and vitamins that can change the colour of urine:</p>\n\n<ul>\n<li>Yellow or yellow-green: cascara, sulfasalazine, the B vitamins.</li>\n<li>Orange: rifampicin, sulfasalazine, the B vitamins, vitamin C.</li>\n<li>Pink or red: phenolphthalein, propofol, rifampicin, laxatives containing senna.</li>\n<li>Green or blue: amitriptyline, cimetidine, indomethacin, promethazine, propofol, triamterene, several multi-vitamins.</li>\n<li>Brown or brownish-black: levodopa, metronidazole, nitrofurantoin, some anti-malarial agents, methyldopa, laxatives containing cascara or senna.</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.webmd.boots.com/urinary-incontinence/urine-colour-changes\" rel=\"noreferrer\">Urinary Incontinence health centre</a>}</p>\n\n<hr>\n\n<p>If you worry about your urine color (apart of contacting your doctor of course), you may purchase <a href=\"http://en.wikipedia.org/wiki/Urine_test_strip\" rel=\"noreferrer\">urine test strips</a> for determination of leukocytes, nitrite, urobilinogen, protein, pH, blood, specific gravity, ketone, bilirubin and glucose in urine. You can easily check if your infection is gone or not.</p>\n\n<hr>\n\n<p>See the following chart (The Color of Pee) found at <a href=\"http://health.clevelandclinic.org/2013/10/what-the-color-of-your-urine-says-about-you-infographic/\" rel=\"noreferrer\">Cleveland Clinic</a>:</p>\n\n<p><a href=\"http://healthhub.wpengine.netdna-cdn.com/wp-content/uploads/2013/10/13-HHB-1407-The-Color-of-Pee-Infographic_FNL-finalnm.pdf\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/wnF9a.jpg\" alt=\"The Color of Pee: Pale straw, Transparent Yellow, Dark yellow, Amber of honey, Syrup, Pink, Orange, Blue, Green, Foaming or fizzing\"></a></p>\n\n<p>^{See also <a href=\"http://healthhub.wpengine.netdna-cdn.com/wp-content/uploads/2013/10/13-HHB-1407-The-Color-of-Pee-Infographic_FNL-finalnm.pdf\" rel=\"noreferrer\">PDF version</a> of it.}</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.webmd.com/urinary-incontinence-oab/features/the-truth-about-urine\" rel=\"noreferrer\">What do urine color and odor changes mean?</a> at WebMD</li>\n</ul>\n", "score": 11 }, { "answer_id": 117, "body": "<p>The anti-biotic could possibly be having an antidiuretic effect. This reduces the amount of water in urine, and so the natural yellow hue is intensified.</p>\n\n<p>There is a definition of an <a href=\"https://en.wikipedia.org/wiki/Antidiuretic\" rel=\"nofollow\">antidiuretic at Wikipedia</a>. The key element of the body's natural ability to retain urine is <a href=\"https://en.wikipedia.org/wiki/Vasopressin\" rel=\"nofollow\">Vasopressin</a>.</p>\n\n<p>There are natural remedies for both urine retention and lack of urine retention. Try:</p>\n\n<ul>\n<li>LiveStrong : <a href=\"http://www.livestrong.com/article/195020-natural-antidiuretic-herbs/\" rel=\"nofollow\">Antidiuretic</a></li>\n<li>LiveStrong : <a href=\"http://www.livestrong.com/article/293172-list-of-natural-diuretics/\" rel=\"nofollow\">Diuretic</a></li>\n</ul>\n", "score": 5 } ]

[ "side-effects", "coloration-discoloration", "antibiotics", "urine", "urinary-system" ]

[ { "answer_id": 267, "body": "<p>Firstly, removing all <strong>added</strong> sugars from you diet certainly will improve your general health in the long term due to the decreased risk of diabetes: your blood glucose level will be more stable with less variability and your diet will include less \"empty calories\". In order to endure in work, in hobbies, in exercise and in day to day living does not rewuire added sugar in a diet. They are bad.</p>\n\n<p>Removing <strong>carbohydrates</strong> from your diet may have some negative impact but not necessarily. Classic low carb diets recommend to remove all substances with a high glycemic index (GI) from your diet. The higher the GI, the faster your blood glucose level will rise when digesting the food. White bread or white rice are examples of foods with a high GI value. In the very extreme, a low carb diet may result in ketosis, which means that your body will get slightly acidic and all your energy consumption is due to burning fat. Removing all carbohydrates stops the citric acid cycle inside cells and this results in the formation of ketone substances which are acidic.</p>\n\n<p>Ketosis may improve your weight loss by burning fat more efficiently. However there are considerable between-subject variations in this. Low carb diets and subsequent ketosis may result in nausea, headaches and general illness. Not all people tolerate low carb diets or ketosis.</p>\n\n<p>If you perform long duration exercises I can´t recommend removing high GI substances from your diet. Skeletal muscles need a lot of energy while doing long duration exercises. The most important energy storage is muscle glycogen. This is consumed in long duration exercises, and after it runs out the body starts to use fats and proteins. Foods with a high GI value are important to restore your muscle glycogen storages after exercise. Therefore removing, say, white rice from your diet won´t be good for exercise if they are usually long duration. Interval or strength training is a different issue. It is also important to note that even a long day at work may be similar to long duration exercise. How well your body does tolerate the lack of your muscle glycogen, is very depending on your general health and fitness.</p>\n", "score": 9 } ]

[ "nutrition", "diet", "sugar" ]

[ { "answer_id": 284, "body": "<p>The reason why you should see a doctor right away is because some causes of sudden hearing loss need to be treated right away. Common causes of sudden hearing loss are <a href=\"http://www.nidcd.nih.gov/health/hearing/pages/sudden.aspx\">[1]</a></p>\n\n<ul>\n<li>infectious disease</li>\n<li>trauma such as head injury</li>\n<li>autoimmune disease such as Cogan's syndrome</li>\n<li>ototoxic drugs</li>\n<li>blood circulation problems</li>\n<li>a tumor on the nerve that connects the brain to the ear</li>\n<li>neurology disease and disorders such as multipe sclerosis</li>\n<li>disorders of the inner ear such as Meniere's disease</li>\n</ul>\n\n<p>Having to see a doctor right away does not imply the hearing loss will be permanent, but since some of the causes of sudden hearing loss can be serious, the need to see a specialist sooner rather than later is paramount.</p>\n\n<p>Additionally, \"treatment is directed at any known cause of the sudden deafness. When the cause is unknown, many doctors try giving corticosteroids along with antiviral drugs effective against herpes simplex (such as valacyclovir or famciclovir). <a href=\"http://www.merckmanuals.com/home/ear_nose_and_throat_disorders/hearing_loss_and_deafness/sudden_deafness.html\">[2]</a>\"</p>\n", "score": 15 }, { "answer_id": 285, "body": "<p>According to the <a href=\"http://www.nidcd.nih.gov/health/hearing/pages/sudden.aspx\" rel=\"noreferrer\">U.S. Department of Health &amp; Human Services</a>, a sudden hearing loss (Sudden Sensorineural Hearing Loss) is considered as a medical emergency as the treatment is more efficient if given as soon as possible:</p>\n\n<blockquote>\n <p>[...] delaying SSHL diagnosis and treatment may decrease the effectiveness\n of treatment.</p>\n</blockquote>\n\n<p>This appears in the section 1 of the linked document. </p>\n\n<p>This only answers your main question though, not the secondaries, as no further detail is given regarding why the treatment could be less efficient over the time. But the diagnosis and the treatment are both explained.</p>\n", "score": 10 } ]

[ "emergency", "hearing" ]

[ { "answer_id": 453, "body": "<p><a href=\"http://www.who.int/foodsafety/areas_work/food-technology/faq-genetically-modified-food/en/\">The WHO considers the genetically modified food currently on the market to be safe</a></p>\n\n<blockquote>\n <p><strong>8. Are GM foods safe?</strong></p>\n \n <p>Different GM organisms include different genes inserted in different\n ways. This means that individual GM foods and their safety should be\n assessed on a case-by-case basis and that it is not possible to make\n general statements on the safety of all GM foods.</p>\n \n <p>GM foods currently available on the international market have passed\n safety assessments and are not likely to present risks for human\n health. In addition, no effects on human health have been shown as a\n result of the consumption of such foods by the general population in\n the countries where they have been approved. Continuous application of\n safety assessments based on the Codex Alimentarius principles and,\n where appropriate, adequate post market monitoring, should form the\n basis for ensuring the safety of GM foods.</p>\n</blockquote>\n\n<p><a href=\"http://www.fda.gov/Food/FoodScienceResearch/Biotechnology/ucm346030.htm\">The FDA also considers them safe</a></p>\n\n<blockquote>\n <p><strong>3. Are foods from genetically engineered plants safe?</strong></p>\n \n <p>Foods from genetically engineered plants must meet the same\n requirements, including safety requirements, as foods from\n traditionally bred plants. FDA has a consultation process that\n encourages developers of genetically engineered plants to consult with\n FDA before marketing their products. This process helps developers\n determine the necessary steps to ensure their food products are safe\n and lawful. The goal of the consultation process is to ensure that any\n safety or other regulatory issues related to a food product are\n resolved before commercial distribution. Foods from genetically\n engineered plants intended to be grown in the United States that have\n been evaluated by FDA through the consultation process have not gone\n on the market until the FDA’s questions about the safety of such\n products have been resolved.</p>\n \n <p><strong>8. Are foods from genetically engineered plants more likely to (1) cause an allergic reaction or (2) be toxic?</strong></p>\n \n <p>The foods we have evaluated through the consultation process have not\n been more likely to cause an allergic or toxic reaction than foods\n from traditionally bred plants. When new genetic traits are introduced\n into plants, the developer evaluates whether any new material could be\n (1) allergenic or (2) toxic if consumed in foods made from the\n genetically engineered plants or from ingredients derived from these\n plants.</p>\n \n <p><strong>10. Are there long-term health effects of foods from genetically engineered plants?</strong></p>\n \n <p>When evaluating the safety of food from genetically engineered plants,\n scientists with experience in assessing the long-term safety of food\n and food ingredients consider several factors, such as information\n about the long-term safety of the food from traditionally bred crops\n in combination with information on the food safety of the newly\n introduced traits. Foods from genetically engineered plants that have\n been evaluated by FDA through the consultation process have not gone\n on the market until the FDA’s questions about the safety of such\n products have been resolved.</p>\n</blockquote>\n\n<p><a href=\"http://www.aaas.org/sites/default/files/AAAS_GM_statement.pdf\">The AAAS also declared that eating Genetically modified food is safe</a>:</p>\n\n<blockquote>\n <p>The World Health Organization, the American Medical Association, the\n U.S. National Academy of Sciences, the British Royal Society, and\n every other respected organization that has examined the evidence has\n come to the same conclusion: consuming foods containing ingredients\n derived from GM crops is no riskier than consuming the same foods\n containing ingredients from crop plants modified by conventional plant\n improvement techniques.</p>\n</blockquote>\n\n<p>There is a broad scientific consensus that the genetically modified crops on the market are safe. There is also quite rigorous testing of any new GM crop before they are approved.</p>\n\n<p>There are real concerns like allergies, as genetically modified organisms typically add a protein that wasn't present before in those organisms. Any protein can potentially be allergenic, because of this the allergenicity is tested before the modified crop is approved.</p>\n\n<p>There are a few studies that showed negative effects of GMOs on rats, but most of them were from a single research group lead by Gilles-Éric Séralini and have been widely criticized (<a href=\"http://en.wikipedia.org/wiki/S%C3%A9ralini_affair\">summary of the Séralini results and the criticism on Wikipedia</a>, <a href=\"https://www.sciencebasedmedicine.org/the-seralini-gmo-study-retraction-and-response-to-critics/\">Blog post on Science Based Medicine</a>). <a href=\"http://www.elsevier.com/about/press-releases/research-and-journals/elsevier-announces-article-retraction-from-journal-food-and-chemical-toxicology\">The 2012 study from Séralini was also retracted by the publisher</a> and they stated that no conclusions could be reached from the experiments, mostly because the sample size was too small.</p>\n\n<p>There is a vast consensus among scientists and regulatory agencies that genetically modified food is safe. </p>\n", "score": 14 }, { "answer_id": 441, "body": "<p>GM food topic is controversial and it's subject of protests, vandalism, referenda, legislation, court action and scientific disputes and this involve consumers, biotechnology companies, governmental regulators, non-governmental organizations and scientists.</p>\n\n<p>The main concerns about GM (genetic modified) <a href=\"http://en.wikipedia.org/wiki/Genetically_modified_food\" rel=\"nofollow\">food</a> and <a href=\"http://en.wikipedia.org/wiki/Genetically_modified_crops\" rel=\"nofollow\">crops</a> is whether they have any negative effects on our health and the environment. And before implementation of these new GM strategies, we should take a full risk assessment which is necessary to understand the possible impacts.</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Transgenesis\" rel=\"nofollow\">Transgenesis</a> of food organisms is likely to grow further and used in the world food supply.</p>\n\n<p>Genetic engineering and breeding has aim of building plants that are superior (\"superweeds\" and \"superbugs\") which holds great promise.</p>\n\n<p>GM crops (such as corn, soybean, rapeseed and cotton) already been produced a range of GM characters such as:</p>\n\n<ul>\n<li>resistance to certain viral pathogens (cucumber mosaic virus), insect, pests, diseases (citrus greening disease) or environmental conditions,</li>\n<li>reduction of spoilage,</li>\n<li>resistance to chemical treatments (e.g. herbicide),</li>\n<li>enhancing yields or improved nutritional value,</li>\n<li>modification of enzymes involved in bioprocessing^{2006, 2007},</li>\n<li>altering oil content,</li>\n<li>tomato - delayed fruit ripening,</li>\n<li>alfalfa - aimed at the reduction of lignin content^{<a href=\"http://en.wikipedia.org/wiki/Alfalfa#Genetically_modified_alfalfa\" rel=\"nofollow\">wiki</a>},</li>\n<li>and many more</li>\n</ul>\n\n<h3>Health concerns</h3>\n\n<p>However some health groups claim that there is potential long-term impact on human health have not been adequately assessed^{<a href=\"http://www.argenbio.org/adc/uploads/pdf/bma.pdf\" rel=\"nofollow\">2004</a>,<a href=\"http://www.phaa.net.au/documents/policy/GMFood.pdf\" rel=\"nofollow\">2007</a>}, however the broad scientific consensus is that food on the market derived from GM crops poses no greater risk than conventional food^{<a href=\"http://www.sciencedirect.com/science/article/pii/S0306919210000254\" rel=\"nofollow\">2010</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120150/\" rel=\"nofollow\">2011</a>, <a href=\"http://www.aaas.org/news/aaas-board-directors-legally-mandating-gm-food-labels-could-%E2%80%9Cmislead-and-falsely-alarm\" rel=\"nofollow\">2012</a>}.</p>\n\n<p>In general those who create genetically engineered seeds argue the seeds are safe and critics say that FDA has relied on studies the industry paid for in comparison with overseas studies which show increasing signs of concern (e.g. increasing the size of organs in mice).</p>\n\n<p>The main concerns raised by <a href=\"http://en.wikipedia.org/wiki/British_Medical_Association\" rel=\"nofollow\">BMA</a> (<a href=\"http://www.argenbio.org/adc/uploads/pdf/bma.pdf\" rel=\"nofollow\">PDF</a>) in 2004 are:</p>\n\n<ul>\n<li><p>Allergens.</p>\n\n<ul>\n<li><p>Possible effects of GM foods on allergic responses.</p>\n\n<blockquote>\n <p>It\n remains possible that any new food products could elicit new allergies.</p>\n \n <p>There is evidence that the food matrix can affect the release of other\n nutrients during digestion and it seems likely that it can also influence the release and digestion of\n allergens in the digestive tract.</p>\n \n <p>With regard to sensitisation it is still not known whether other\n components in the food matrix can have an adjuvant effect on the development of IgE responses in\n susceptible individuals.</p>\n \n <p>The concerns are that they may contain allergenic substances due to introduction of new genes into crops^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12746139\" rel=\"nofollow\">2003</a>}.</p>\n</blockquote></li>\n</ul></li>\n<li><p>Nutritional status^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12746139\" rel=\"nofollow\">2003</a>}.</p>\n\n<blockquote>\n <p>It is possible that GM technology could lead to unpredicted harmful\n changes in the nutritional status of foods^{MRC 2000}.</p>\n \n <p>GM foods could conceivably have different effects on those of poor nutritional status and/or those belonging to ‘vulnerable groups’ (notably the foetus, infants, children, pregnant and lactating women, the elderly and those with chronic disease) when compared with healthy individuals.</p>\n</blockquote></li>\n<li><p>Genetic transfer.</p>\n\n<ul>\n<li><p>The fate of GM plant DNA in the digestive system.</p>\n\n<blockquote>\n <p>While gene transfer has been observed in the gastrointestinal tract of some mammals ^{<a href=\"http://informahealthcare.com/doi/abs/10.3109/08910609109140149\" rel=\"nofollow\">1991</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8111532\" rel=\"nofollow\">1993</a>} and birds ^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC91691/\" rel=\"nofollow\">1999</a>} there is still great uncertainty as to the extent and the consequences of this transfer ^{<a href=\"http://www.newscientist.com/article/mg17523530.400-does-it-matter-if-genes-can-jump-from-gm-food-to-bugs-in-human-gut.html\" rel=\"nofollow\">2002</a>}.</p>\n</blockquote></li>\n<li><p>Potential effects on human health resulting from the use of viral DNA in plants.</p>\n\n<blockquote>\n <p>Plant viral DNA sequences are commonly used in the construction of the genes inserted into GM plants.</p>\n \n <p>The concern is that genetic engineering often involves the use of antibiotic-resistance genes as \"selectable markers\" and this could lead to production of antibiotic-resistant bacterial strains that are resistant to available antibiotics. This would create a serious public health problem.^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12746139\" rel=\"nofollow\">2003</a>}</p>\n</blockquote></li>\n</ul></li>\n<li><p>Environmental impact.</p>\n\n<blockquote>\n <p>Recent UK Farm Scale Evaluations of GM herbicide-tolerant\n crops (GMHT)^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1693271/\" rel=\"nofollow\">2003</a>} indicate that if GMHT beet and spring oilseed rape were introduced and managed as they were in the trial, a significant reduction would be expected in weed biomass and weed seed return. This would result in fewer nectar resources for pollinators and fewer weed seed resources for granivorous birds.</p>\n \n <p>Canadian farmers found that their fields filled with stray GM crop plants known as ‘volunteers’. These were resistant, not only to the substance against which the main crop was engineered, but to the other two herbicides used as well.^{<a href=\"http://www.economist.com/node/975762\" rel=\"nofollow\">2002</a>} </p>\n \n <p>The potential impact of GM crops on the environment and biological diversity is the issue that has given rise to most concern and it remains in doubt^{<a href=\"http://tna.europarchive.org/20120605160537/http://www.food.gov.uk/gmdebate/?view=GM%20Microsite\" rel=\"nofollow\">2003</a>}.</p>\n</blockquote></li>\n<li><p>Experimental design.</p>\n\n<blockquote>\n <p>Research into the possible health effects of GM foods in this country has been limited to date by the lack of firm hypotheses regarding such effects, difficulties of defining individual consumption, and the generally low levels of consumption of GM foods.</p>\n</blockquote></li>\n</ul>\n\n<p>Some other groups such as Greenpeace and WWF have concerns that risks of GM food have not been adequately identified and managed.</p>\n\n<p>One cellular biologist, David Williams, says that anyone in this field knows that genome is not a static environment and can be transformed by several different means, and it can happen generations later which can result in potentially toxic plants slipping through testing^{<a href=\"http://www.scientificamerican.com/article/the-truth-about-genetically-modified-food/\" rel=\"nofollow\">D. Williams</a>}.</p>\n\n<p>Some other studies indicated that there may be specific health risks associated with consumption of GM foods, such as:</p>\n\n<ul>\n<li><p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16119037\" rel=\"nofollow\">The 2005 study by Allergy Asthma Proc.</a> toward assessing the allergenic potential of GMO food.</p>\n\n<blockquote>\n <p>The skin test results of 49 patients showed 13 positive results to wild soybeans and 8 positive results to GMO soybeans. One patient had a positive skin test result to GMO soybeans only.</p>\n</blockquote></li>\n<li><p><a href=\"http://gmopundit.blogspot.co.uk/2008/11/full-report-of-austrian-study-on-gm.html\" rel=\"nofollow\">The 2008 study of biological effects of transgenic maize NK603xMON810 fed in long term reproduction studies in mice.</a></p>\n\n<blockquote>\n <p>The RACB trial showed time related negative reproductive effects of the GM maize under the given experimental conditions. The outcome of this study suggests that future studies on the safety of GM feed and food should include reproduction studies.</p>\n</blockquote></li>\n<li><p>Study in 2007 &amp; 2009 found that <a href=\"https://en.wikipedia.org/wiki/MON_810\" rel=\"nofollow\">MON810’s transgene structure in GM maize</a> used around the world caused liver, kidney, and heart damage in rats, however EFSA reviewed and concluded that the differences observed were within a normal range for control rats and deemed the statistical methods used inappropriate.</p></li>\n</ul>\n\n<hr>\n\n<h3>Other concerns</h3>\n\n<p>People questioning this new technology and activists around the world demonstrate to express their concerns while food industries trying to push this technology forward.</p>\n\n<p>There are common claims from opponents that consumption of GM can cause cancer or birth defects, however there currently is no evidence to support this claim.</p>\n\n<p>Currently labeling of GMO products in the marketplace is required over 60 countries^{<a href=\"http://www.burlingtonfreepress.com/story/news/politics/2014/04/27/gmo-labeling-came-pass-vermont/8166519/\" rel=\"nofollow\">2014</a>}, the US does not require this.</p>\n\n<hr>\n\n<h3>Conclusion</h3>\n\n<p>Based on above, many unanswered questions remain, especially with potential long-term impact of GM foods on animal and human health and the environment and it currently. The GM foods are very complex and currently there is a lack of evidence-based research with regard to medium/long-effects on health and it remains as a matter of great public concern. Further research is required on how best to carry the experiments (modern profiling techniques and define the 'normal' compositions of conventional plants), risk assessments and surveillance studies with respect to GM crops and foods.</p>\n\n<p>The Royal Society in their <a href=\"https://royalsociety.org/~/media/royal_society_content/policy/publications/2002/9960.pdf\" rel=\"nofollow\">2002 report</a> saying there is at present no evidence that GM foods cause allergic reactions, use of\nspecific viral DNA sequences in GM plants are negligible and conclude that consumption poses no significant risk to human health, and that ingestion of GM DNA has no effect.</p>\n\n<p>Study from <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12746139\" rel=\"nofollow\">2003 by J Toxicol Environ Health</a> summarise it:</p>\n\n<blockquote>\n <p>The review of available literature indicates that the genetically modified crops available in the market that are intended for human consumption are generally safe; their consumption is not associated with serious health problems. However, because of potential for exposure of a large segment of human population to genetically modified foods, more research is needed to ensure that the genetically modified foods are safe for human consumption.</p>\n</blockquote>\n\n<p>Currently the broad scientific consensus states that food on the market derived from GM crops poses no greater risk to human health than conventional food^{<a href=\"http://www.sciencedirect.com/science/article/pii/S0306919210000254\" rel=\"nofollow\">2010</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21546547\" rel=\"nofollow\">2011</a>, <a href=\"http://www.aaas.org/news/aaas-board-directors-legally-mandating-gm-food-labels-could-%E2%80%9Cmislead-and-falsely-alarm\" rel=\"nofollow\">2012</a>}.</p>\n\n<hr>\n\n<p>Further readings:</p>\n\n<ul>\n<li><p>Wikipedia</p>\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_food\" rel=\"nofollow\">Genetically modified food</a> (GM food)</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_crops\" rel=\"nofollow\">Genetically modified crops</a> (GMOs, biotech crops, transgenic plants)</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_organism\" rel=\"nofollow\">Genetically modified organism</a> (GMO)</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_food_controversies\" rel=\"nofollow\">Genetically modified food controversies</a></li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetic_engineering\" rel=\"nofollow\">Genetic engineering</a> (<a href=\"http://en.wikipedia.org/wiki/Transgenesis\" rel=\"nofollow\">Transgenesis</a>, <a href=\"http://en.wikipedia.org/wiki/Cisgenesis\" rel=\"nofollow\">Cisgenesis</a>, Subgenic)</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Plant_breeding#Genetic_modification\" rel=\"nofollow\">Plant breeding: Genetic modification</a></li>\n<li><a href=\"http://en.wikipedia.org/wiki/Detection_of_genetically_modified_organisms\" rel=\"nofollow\">Detection of genetically modified organisms</a></li>\n<li><p><a href=\"http://en.wikipedia.org/wiki/Category:Genetically_modified_organisms_in_agriculture\" rel=\"nofollow\">GM organisms in agriculture</a>:</p></li>\n<li><p><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_soybean\" rel=\"nofollow\">GM soybean</a> (controversies: safety),</p></li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_tomato\" rel=\"nofollow\">GM tomato</a>,</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_wheat\" rel=\"nofollow\">GM wheat</a> (controversies: safety, ecological, intellectual property law, contamination of the non-GM, etc.),</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_rice\" rel=\"nofollow\">GM rice</a> (controversies: safety, should be labeled, intellectual property, contamination of the non-GM, etc.)</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Alfalfa#Genetically_modified_alfalfa\" rel=\"nofollow\">GM alfalfa</a> (and legal issues in the UK),\n\n\n<blockquote>\n <p>Growers can spray fields of Roundup Ready alfalfa with the glyphosate herbicide and kill the weeds without harming the alfalfa crop.</li>\n <li><p><a href=\"http://en.wikipedia.org/wiki/AquAdvantage_salmon\" rel=\"nofollow\">AquAdvantage salmon</a> (trade name for GM Atlantic salmon)</p></p>\n</blockquote>\n\n<p>Concerns: survival, rate of growth, smoltification, allergenicity, muscle fibers, lack of fertilization, swimming capabilities, decreased sperm velocity</p></li>\n<li><p><a href=\"http://en.wikipedia.org/wiki/Genetically_modified_canola\" rel=\"nofollow\">GM canola</a></p></li>\n<li><a href=\"https://en.wikipedia.org/wiki/Genetically_modified_maize\" rel=\"nofollow\">GM maize</a> (Effects on nontarget insects, Gene flow, corn recalls)</li>\n</ul></li>\n<li><p><a href=\"http://www.scientificamerican.com/article/the-truth-about-genetically-modified-food/\" rel=\"nofollow\">The Truth about Genetically Modified Food</a> at Scientific American</p></li>\n<li><p><a href=\"http://www.innerself.com/Health/frankenfood.htm\" rel=\"nofollow\">Are You Eating Frankenfood?</a> article by Martin Teitel, Ph.D.\nand Kimberly A. Wilson</p>\n\n<blockquote>\n <p>Results coming in from the first objective tests are not encouraging. Scientists issue cautionary statements almost weekly, ranging from problems with monarch butterflies dying from genetically modified corn pollen to the danger of violent allergic reactions to genes introduced into soy products, as well as experiments showing a variety of actual and suspected health problems for cows fed genetically engineered hormones and the humans who drink their milk. And this doesn't even consider slow-acting problems that might not show up for years or decades. Who decided this was an acceptable risk?</p>\n</blockquote></li>\n</ul>\n", "score": 7 } ]

[ "nutrition", "resistance", "artificial", "genetic-engineering", "gmo" ]

[ { "answer_id": 540, "body": "<h1>Shampooing</h1>\n<p>The first synthetic shampoos were introduced in the 1930's and by '70s and '80s, daily shampooing became norm in the US. So shampooing in the modern sense (water to produce a soapy lather) is only about 100 years old.</p>\n<p>Our modern shampoos are a combination of <a href=\"https://en.wikipedia.org/wiki/Surfactant\" rel=\"noreferrer\">surfactants</a> (such as <a href=\"https://en.wikipedia.org/wiki/Sodium_dodecyl_sulfate\" rel=\"noreferrer\">SLS</a>) which dissolve natural oils (<a href=\"https://en.wikipedia.org/wiki/Sebaceous_gland\" rel=\"noreferrer\">sebum</a>) and remove dirt particles. As result, it reduces the natural oils in your hair and scalp making it drier than usual, causing the scalp to produce more oil to compensate.</p>\n<p>According to some dermatologists, a gradual reduction in shampoo causes <a href=\"https://en.wikipedia.org/wiki/Sebaceous_gland\" rel=\"noreferrer\">sebaceous glands</a> to produce sebum at a slower rate resulting in less oil on the scalp and in the hair^{<a href=\"http://www.npr.org/templates/story/story.php?storyId=102062969\" rel=\"noreferrer\">2009</a>}.</p>\n<p>Michelle Hanjani, a dermatologist at Columbia University explains:</p>\n<blockquote>\n<p>If you wash your hair every day, you're removing the sebum, then the oil glands compensate by producing more oil&quot;</p>\n</blockquote>\n<p>She recommends that patients wash their hair no more than two or three times a week.</p>\n<p>In the 2010 book Packing for Mars, Soviet research said^{<a href=\"https://en.wikipedia.org/wiki/Special:BookSources/9780393068474\" rel=\"noreferrer\">2010</a>}:</p>\n<blockquote>\n<p>the skin halts its production of sebum—after five to seven days of not bathing</p>\n</blockquote>\n<p>However this could vary greatly from person to person, as some people could respond better to some products with different concentrations of surfactants.</p>\n<p>For example if you have &quot;oily hair&quot; you need a higher concentration of SLS to help dissolve the oils, when you have &quot;dry and frizzy hair&quot;, it would exacerbate the problem.</p>\n<p>In 2007 radio audition, Australian <a href=\"https://en.wikipedia.org/wiki/Richard_Glover_(radio_presenter)\" rel=\"noreferrer\">Richard Glover</a> decided to challenge his audience to go without shampoo for six weeks. 86 percent of those who 500 people who participated reported that &quot;their hair was either better or the same&quot;^{<a href=\"https://en.wikipedia.org/wiki/No_poo\" rel=\"noreferrer\">wiki</a>}.</p>\n<h3>Studies</h3>\n<p>A <a href=\"http://journal.scconline.org/pdf/cc1997/cc048n02/p00117-p00121.pdf\" rel=\"noreferrer\">study from 1997</a> showed a link between excessive oil production and anti-dandruff shampoos containing selenium sulfide.</p>\n<blockquote>\n<p>Study was conducted in 120 men in order to quantify the effect of eight proprietary antidandruff shampoos on sebum flow dynamic.</p>\n<p>Two shampoos exhibited a significant effect upon the sebum follicular reservoir, steadily increasing the sebum excretion rate in time. One other product induced a significant decrease in sebum output.</p>\n<p>Only a few topical products are known to decrease the sebum output at the skin surface:</p>\n<p>Among them, the effect of progesterone, astringents, erythromycin-zinc complex, corticosteroids, and elubiol have been documented.</p>\n</blockquote>\n<p>For older studies, see: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/4177572\" rel=\"noreferrer\">1968</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/6580909\" rel=\"noreferrer\">1983</a></p>\n<p>In 2013, the FDA announced that triclosan was found to affect hormone levels in animals^{<a href=\"http://www.fda.gov/forconsumers/consumerupdates/ucm205999.htm\" rel=\"noreferrer\">FDA</a>}.</p>\n<blockquote>\n<p>Animal studies have shown that triclosan alters hormone regulation. However, data showing effects in animals don’t always predict effects in humans.</p>\n</blockquote>\n<p>A recent study from 2014 showed that shampooing impact on cortisol levels in human hair:</p>\n<blockquote>\n<p>Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies.</p>\n</blockquote>\n<p>Based on above it seems that chemical properties in modern shampoos can affect our hormones, however more studies needs to be conducted to see how exactly it affects our natural oil production (<a href=\"https://en.wikipedia.org/wiki/Sebaceous_gland\" rel=\"noreferrer\">sebum</a>).</p>\n<p>Read more:</p>\n<ul>\n<li><a href=\"http://www.nbcnews.com/id/30337386/ns/health-skin_and_beauty/t/ditching-shampoo-dirty-little-beauty-secret/#.VS_UjJTF9v1\" rel=\"noreferrer\">Ditching shampoo a dirty little beauty secret</a> at NBC</li>\n<li><a href=\"http://www.npr.org/templates/story/story.php?storyId=102062969\" rel=\"noreferrer\">When It Comes To Shampoo, Less Is More</a> at NPR</li>\n<li><a href=\"http://www.nytimes.com/2008/02/21/fashion/21SKINOne.html\" rel=\"noreferrer\">Of Course I Washed My Hair Last Year</a></li>\n<li>Curly Girl by Michele Bender (2002)</li>\n<li><a href=\"https://en.wikipedia.org/wiki/No_poo\" rel=\"noreferrer\">No poo</a> (<strong>no</strong> sham<strong>poo</strong>) at Wikipedia</li>\n</ul>\n", "score": 5 }, { "answer_id": 1204, "body": "<p>_{To complete the answer of kenorb, I would like to add the second part}</p>\n<h1>Soaping</h1>\n<p>According to the <a href=\"https://www.aad.org/dermatology-a-to-z/health-and-beauty/general-skin-care/dry-skin-tips\" rel=\"nofollow noreferrer\">America Academy of Dermatology</a>, the number one tip to prevent dry skin is:</p>\n<blockquote>\n<p>Prevent baths and showers</p>\n</blockquote>\n<p><a href=\"http://www.nytimes.com/2010/10/31/fashion/31Unwashed.html?_r=3&amp;pagewanted=1&amp;ref=fashion\" rel=\"nofollow noreferrer\">The Great Unwashed</a>, The New York Times explains further:</p>\n<blockquote>\n<p>[...] researchers have discovered that just as the gut contains good bacteria that help it run more efficiently, so does our skin brim with beneficial germs that we might not want to wash down the drain. “Good bacteria are educating your own skin cells to make your own antibiotics,” said Dr. Richard Gallo, chief of the dermatology division at the University of California, San Diego, and “they produce their own antibiotics that kills off bad bacteria.”</p>\n<p>Some people have long complained that showering too much makes their skin drier or more prone to flare-ups of, say, eczema, and Dr. Gallo said that scientists are just beginning to understand why. “<strong>It’s not just removing the lipids and oils on your skin that’s drying it out,</strong>” he said. <strong>It could be “removing some of the good bacteria that help maintain a healthy balance of skin.&quot;</strong></p>\n</blockquote>\n<p>There is a note:</p>\n<blockquote>\n<p>But Elaine Larson, a professor at the Columbia University School of Nursing with a Ph.D. in epidemiology, cautioned that subway riders, gymgoers and others who come into <strong>contact with many strangers</strong> should consider soaping up. “If it’s cold and flu season, you want to get rid of the stuff that isn’t a part of your own normal germs,” she said.</p>\n</blockquote>\n<h1>However</h1>\n<p>If you are about to think that not shower/bath because it's make your skin dry, there are other reasons to reconsider. According to <a href=\"http://www.medicaldaily.com/benefits-cold-showers-7-reasons-why-taking-cool-showers-good-your-health-289524\" rel=\"nofollow noreferrer\">Medical Daily</a>, there is 7 reasons to take a <strong>cool</strong> shower:</p>\n<ol>\n<li>Increases Alertness</li>\n<li>“Seal” the pores in the skin and scalp</li>\n<li>Improves Immunity and Circulation</li>\n<li>Stimulates Weight Loss</li>\n<li>Speeds Up Muscle Soreness and Recovery</li>\n<li>Eases Stress</li>\n</ol>\n", "score": 3 } ]

[ "dermatology", "oil-of-skin" ]

[ { "answer_id": 512, "body": "<p>The OP observes:</p>\n\n<blockquote>\n <p>When I was a smoker, my own SpO2 was usually 100%.</p>\n</blockquote>\n\n<p>Although <em>long-term</em> smoking often does lead to changes in the lungs that cause hypoxemia (low peripheral O₂ Saturation, a.k.a. SpO₂), these effects are not immediate. In fact, in the short term, SpO₂ may even be spuriously <strong>high</strong>, consistent with your observation. We should distinguish between the factors that drive changes in O₂ saturation in long-term when compared to short-term smoking.*</p>\n\n<h2>Short term</h2>\n\n<p><a href=\"https://health.stackexchange.com/a/505/165\">Another answer</a> discussed the increased carbon monoxide (CO) levels in smokers, which <em>is</em> <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20739872\" rel=\"noreferrer\">an immediate effect of the inhaled cigarette smoke that is dose-dependent</a> (i.e. heavy smokers will inhale more CO than light smokers). </p>\n\n<p><a href=\"http://www.hopkinsmedicine.org/healthlibrary/test_procedures/pulmonary/oximetry_92,p07754/\" rel=\"noreferrer\">A pulse oximeter</a> measures the percentage of circulating hemoglobin to which oxygen is bound. By standard pulse oximetry, <a href=\"http://www.merckmanuals.com/professional/injuries-poisoning/poisoning/carbon-monoxide-poisoning\" rel=\"noreferrer\">carboxy-hemoglobin is indistinguishable from oxyhemoglobin</a>. Also, carbon monoxide causes a left-shift of the <a href=\"http://www.ventworld.com/resources/oxydisso/dissoc.html\" rel=\"noreferrer\">oxyhemoglobin dissociation curve</a>. This means the hemoglobin is holding onto the oxygen more tightly, resulting in a higher saturation of hemoglobin. It is for both of these reasons that students are often taught about the <a href=\"http://medical-dictionary.thefreedictionary.com/Carbon+Monoxide+Poisoning\" rel=\"noreferrer\">“cherry red” appearance of skin</a> and mucous membranes in carbon monoxide poisoning.** In contrast to hypoxemia (low SpO₂) when mucous membranes tend to turn blue due to low oxygen saturation, the hemoglobin saturation in carbon monoxide poisoning will be seen (both by our eyes and by pulse oximetry) as high. <strong><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=buckley+pulse+oximetry+gap\" rel=\"noreferrer\">Pulse oximetry may be spuriously high</a> in smokers due to the presence of carboxyhemoglobin.</strong> </p>\n\n<p>In most young, healthy people, oxygen saturation is 98-100% anyway, so this difference is usually negligible. However, the point remains that the OP’s observation is fully consistent with the effects of short-term smoking.</p>\n\n<h2>Long-term</h2>\n\n<p>Long-term smokers frequently do have low oxygen saturation <em>despite</em> the spurious elevation due to carbon monoxide. A full explanation of the mechanism would require a textbook of respiratory physiology. The basic idea is that the toxins in cigarette smoke lead to inflammation and remodeling in the lung that cause both <a href=\"http://www.nhlbi.nih.gov/health/health-topics/topics/copd\" rel=\"noreferrer\">obstructive pulmonary disease</a> and <a href=\"http://en.wikipedia.org/wiki/DLCO\" rel=\"noreferrer\">decreased alveolar diffusing capacity</a>. </p>\n\n<p>It has been shown that <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=24307008\" rel=\"noreferrer\">early inflammatory changes are present even in young smokers with normal pulmonary function tests</a>. These microscopic changes in the lung do not cause measurable changes in oxygen saturation or pulmonary function tests. However, evidence like this should reinforce to the OP (and any other former smokers around) how absolutely <strong>fabulous</strong> it is that you quit smoking.</p>\n\n<hr>\n\n<p>_\nNotes\n</p>\n\n<p>_{\n*The exact time period (more precisely, number of <a href=\"http://en.wikipedia.org/wiki/Pack-year\" rel=\"noreferrer\">pack-years</a>) after which the long-term effects begin to dominate the acute effects has substantial inter-individual variability.\n}<br>\n_{\n**This is rarely seen in real life, and it would only be present in those with higher doses of CO than that incurred from normal cigarette smoking. The theoretical point remains.\n}</p>\n", "score": 15 }, { "answer_id": 505, "body": "<p>Yes, SpO2 levels can be depressed in smokers, but the body will compensate for some of the effects which can explain why you may have had normal saturation levels. There are also age considerations, as well as how much a person smokes.</p>\n\n<p>One of the culprits in cigarette smoke is CO, or Carbon Monoxide. CO shares the same binding sites as O2 in blood hemoglobin (Hg), and actually has 200 times greater affinity than O2. So when you smoke, the CO travels across and prevents some Hg from picking up oxygen. The net result is that your heart starts working harder to get more blood around, which can keep up your sat levels. There is a decent <a href=\"http://health.howstuffworks.com/wellness/drugs-alcohol/smoking-starve-the-heart-of-oxygen1.htm\" rel=\"nofollow noreferrer\">plain English explanation here</a>.</p>\n\n<p>In addition to this, there are other changes that can occur in longtime smokers. <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC459657/?page=3\" rel=\"nofollow noreferrer\">This study</a> from 1983 found that in females and smokers over 50 have associated increases in red cell volume and reduced plasma volume. This suggests that the body adapts to the decreased O2 count by producing more RBC's. While this sounds like a great adaptation, it also means that with the reduced plasma volume, the blood is \"thicker\", which means that the heart has to work harder to push it around.</p>\n\n<p><a href=\"http://www.bloodjournal.org/content/bloodjournal/41/6/845.full.pdf?sso-checked=true\" rel=\"nofollow noreferrer\">This article</a> also notes decreased plasma volume and greater RBC counts in long time CO exposure subjects as well as other significant blood composition changes.</p>\n\n<p>TL;DR: Yes, O2 saturation is impaired by continued exposure to CO as a long term effect. However, the good news is that the body is remarkably resilient, and depending on length of time a person smokes, the body will start reversing the effects of smoking within a week or two. Shameless self promotion: <a href=\"https://fitness.stackexchange.com/questions/7990/how-long-does-it-take-lungs-to-recover-after-quitting-smoking/7992#7992\">Reversing effects of smoking.</a></p>\n", "score": 6 } ]

[ "smoking", "oxygenation", "biological-parameter" ]

[ { "answer_id": 805, "body": "<p>The original 3500 calorie theory comes from a correspondence <a href=\"http://jama.jamanetwork.com/article.aspx?articleid=328550\" rel=\"nofollow noreferrer\">published in 1959, by a Dr. Max Wishnofsky</a>, where he equates it to pounds lost in observed obese patients.</p>\n\n<p>It's further perpetuated by badly applied mathematics. White adipose tissue has the responsibility for energy storage in the body. This tissue is composed of <a href=\"http://www.sportsci.org/encyc/adipose/adipose.html\" rel=\"nofollow noreferrer\">anywhere from 60% to 85% lipid</a> (fat). If you take the commonly accepted 9 calories of energy per gram of fat (Which is also not quite accurate), you get the following formula:</p>\n\n<p>9 (calories/gram) * 454 grams (grams in a pound) * .85 = 3465 calories.</p>\n\n<p>So, the original estimation was that there were 3500 calories in a pound of human fat, so to lose a pound you had to burn 3500 calories. Since this \"makes sense\", it was widely repeated and used, and became entrenched. It is not accurate, and implying that to lose a pound of fat you have to burn exactly 3500 calories is erroneous.</p>\n\n<p>Edit: While researching something else, I came across this article, titled \"<a href=\"http://www.todaysdietitian.com/newarchives/111114p36.shtml\" rel=\"nofollow noreferrer\">Farewell to the 3500 calorie Rule</a>\", on Today's Dietitian website. One paragraph from the article:</p>\n\n<blockquote>\n <p>It's been estimated that the 3,500-calorie rule is cited in more than 35,000 educational weight-loss sites.1 In September, the Journal of the American Medical Association published a patient handout titled Healthy Weight Loss, in which the first sentence states, \"A total of 3,500 calories equals 1 pound of body fat. This means if you decrease (or increase) your intake by 500 calories daily, you will lose (or gain) 1 pound per week.\"2 Undoubtedly, the 3,500-calorie dogma still is being taught even though it's been shown that it simply doesn't work this way. So where did the 3,500-calorie weight-loss wisdom come from? It originated from researcher Max Wishnofsky, MD, in 1958, who calculated that 1 lb of fat stores approximately 3,500 kcal of energy.3 It was appealingly simple, and it stuck.</p>\n</blockquote>\n", "score": 10 }, { "answer_id": 16875, "body": "<p>It is, at least, overly simplified.</p>\n\n<p>The average amount of water in adipose tissue is 13%. In addition to that, it also contains approx. 3% protein. The remainder is fat.</p>\n\n<p>Lard, which should have a similar calorific value as human fat, provides ~8980 calories per kg.</p>\n\n<p>To simplify this calculation we assume that 1 kg of protein provides 4000 calories and 1 kg of fat 9000 calories (in other words ratios of 1:4 and 1:9).</p>\n\n<p>The average kilo of adipose tissue (fat tissue) contains 840g fat and 30g protein. Which amounts to a calorific value of 7680 calories per kilo.</p>\n\n<p>Translated into pounds that is 3484 calories per pound, which is pretty close to the number in question.</p>\n\n<p>The problem is that this is based on average values that have wide ranges attached to them.</p>\n\n<p>The water content of fat tissue can vary between ~4 and ~40% and the protein content between ~2 and ~3.5%. </p>\n\n<p>This means the calorific value can vary <strong>between 5540 and 8540 calories per kilo (or 2510 and 3870 per pound)</strong> of fat tissue. </p>\n\n<p>Sadly, it also seems that the water content is lower for those above standard weight. So whoever needs to lose a couple of pounds because of health reasons should rather apply 3900 per pound.</p>\n\n<p>The numbers are based on this <a href=\"https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/expphysiol.1962.sp001589\" rel=\"nofollow noreferrer\">study</a>. It is a bit old but as the numbers are based on actual tissue samples, I doubt they are too far away from the truth. What might have changed is the average. At least in some countries, as obesity rates are much higher than 50 years ago.</p>\n\n<p>Regarding the water content of body fat, try a watermelon test. Replace an intake of 1000 calories with watermelon worth 500 calories. Drink as much water as you usually do. The extra water intake will most likely lead to an increase body weight on the next day, even though your calorific intake was lower. </p>\n\n<p>^{The above-mentioned study refers to: \"THE CHEMICAL COMPOSITION OF ADIPOSE TISSUE OF MAN AND MICE.\" LORETTE W. THOMAS, Department of Physiology, Edinburgh University. (1962)}</p>\n", "score": 4 }, { "answer_id": 29009, "body": "<blockquote>\n<p>Every pound of pure body fat that is metabolized yields approximately 3500 kcals, thus a daily caloric deficit of 500 kcals theoretically results in fat loss of approximately one pound per week if the weight loss comes entirely from body fat [7].</p>\n</blockquote>\n<blockquote>\n<p>However, a static mathematical model does not represent the dynamic physiological adaptations that occur in response to an imposed energy deficit [8]. Metabolic adaptation to dieting has been studied in overweight populations and when observed, reductions in energy expenditure amount to as little as 79 kcal/d [9], to as much as 504 kcal/d beyond what is predicted from weight loss [10].</p>\n</blockquote>\n<p><a href=\"https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC4033492\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC4033492</a></p>\n<p>Exploring reference [7], <a href=\"https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC2376744/\" rel=\"nofollow noreferrer\"><em>What is the Required Energy Deficit per unit Weight Loss?</em></a>:</p>\n<blockquote>\n<p>[...] it is now generally acknowledged that this rule of thumb is an oversimplification (1). But under what conditions is this rule of thumb appropriate? In other words, what are the factors that determine the cumulative energy deficit required per unit weight loss?</p>\n</blockquote>\n<p>Note, 3000 kcal = <strong>32.2 MJ per kg</strong>:</p>\n<p><a href=\"https://i.stack.imgur.com/BON1G.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/BON1G.png\" alt=\"The predicted energy density of weight loss expressed as a function of A)initial body fat content or B) initial body weight of women.Data points depict the calculated weight loss energy densities from several published studies in both obese and lean subjects.\" /></a></p>\n<blockquote>\n<p>Figure 1 The predicted energy density of weight loss expressed as a function of A)initial body fat content or B) initial body weight of women.Data points depict the calculated weight loss energy densities from several published studies in both obese and lean subjects.</p>\n</blockquote>\n<p>There is somewhat of a cluster around 3500 calories, slightly below even. (A rule-of-thumb of less calories is better for losing weight since less calories need to be burned.)</p>\n<blockquote>\n<p>The fact that weight loss typically slows over time for a prescribed constant diet (9, 38) suggests that either the energy expenditure decreases with time, or the dietary intervention is relaxed over time, or both.</p>\n</blockquote>\n", "score": 2 } ]

[ "nutrition", "diet", "weight" ]

[ { "answer_id": 10338, "body": "<p><strong>Unquestionably, sexual activity has several benefits for the body and mind.</strong> </p>\n\n<p>People who have a satisfactory sexual life tend to be happier, friendlier, calmer and sleep better. People who are happier, friendlier, calmer and sleep better, tend to need fewer medical appointments. Then again, sex is a touchy subject. Unless you are a psychyatrist, most medical professionals would find it very difficult to find out if an individual patient has a regular and normal sexual life, and even more difficult if they are as pleasurable as they should be. Trying to find out may induce some patients to lie. Worse than that, some may say the doctor is too nosy and never return. </p>\n\n<p>Even if an occasionally uninhibited and outspoken patient says that they have no sexual activity and think they would be much happier if they did, to advise \"go and have sex to improve your general health or to help treat these disorders\" can be risky. If the patient makes wrong choices and unexpected problems are created, malpractice actions may follow. </p>\n\n<p>All a doctor can do is mention that pleasurable sexual activity is good for one's health. So are a good night's sleep and healthy meals, everybody knows that. I'm sure those who enjoy sex, and know where to get a good partner, will have it whenever they want. For those who cannot find a partner or who do not enjoy sex at all, it's no use telling them to go and have it for the sake of their health. They simply won't.</p>\n\n<p>ps - Even if a medical professional were sure some sort of sexual therapy would be of great benefit to an individual patient, any sort of prescription would have to be approved by the FDA or an official Secretary of Health.</p>\n", "score": 4 } ]

[ "treatment-options", "benefits", "endorphins" ]

[ { "answer_id": 1366, "body": "<p>My short answer is : <strong>Brushing your tooth without toothpaste will not cause a greater amount of micro-scratches than if you were to use toothpaste</strong>. </p>\n\n<p>To begin, <strong>tooth paste</strong>, is a product most often made of <strong>abrasive substances</strong> that <strong>increases</strong> the <strong>scrubbing power</strong> of the toothbrush bristles. Some kinds of toothpaste can also accomplish other things, such as reducing dental sensitivity (potassium nitrate, Sensodyne®) or make teeth more resistant to caries and acidity (Fluoride).</p>\n\n<p>In other words it is the <strong>physical movement</strong> of the bristles of the brush that <strong>removes plaque</strong> that accumulates on and between the teeth and gums.</p>\n\n<p>Therefore, it is not the tooth paste that will make the greatest impact on your teeth and gums but <strong>the way you move your toothbrush</strong> on the surfaces of your teeth and gums.</p>\n\n<p>If you brush too aggressively, you will at first cause the gums to recede and then will use prematurely the enamel on your teeth.</p>\n\n<p>Here is a list of things to do to brush properly:</p>\n\n<ul>\n<li><strong>Brush your teeth by using the modified Bass (roll-brush) method</strong>. Keep your toothbrush at a 45º angle and make small circular movements, on a set of 2-3 teeth at a time. Avoid broad, horizontal, back-and-fourth movements, since they will irritate the gums. Once a set of teeth has been brushed, make one sweep from the gum to the teeth, to remove any debris stuck in between.</li>\n<li><strong>Don't put too much pressure</strong>, and use a soft or super-soft bristle toothbrush. If done correctly, the plaque and bio-film will be removed by the movement of the toothbrush bristles. Anything that is harder than what a soft bristle can remove is probably tarter (calcified plaque) which needs to get removed by a dentist or hygienist.</li>\n<li>If you need to remove food stuck between teeth, <strong>use floss</strong>.</li>\n</ul>\n\n<p>A more in-depth look into mechanical plaque control could be done, but it would be somewhat outside the scope of the original question.</p>\n\n<p>One of my references:\n<a href=\"http://www.aapd.org/assets/1/25/Axelsson-03-S1.pdf\">http://www.aapd.org/assets/1/25/Axelsson-03-S1.pdf</a></p>\n", "score": 17 } ]

[ "brushing-teeth", "toothbrush", "toothpaste", "enamel", "rinsing-mouth" ]

[ { "answer_id": 1317, "body": "<p>This subject is very broad and a detailed answer would require to be a whole book. Shortly I can say that vegetarians and vegans have lower rates of <strong>mortality</strong> (both by ischemic heart disease and total) (1-3) and lower incidence rates of <strong>diabetes</strong> (4) and <strong>cancer</strong> (5,6). Vegetarian diets are related to lower <strong>blood pressure</strong> (7,8), lower <strong>body weight</strong> and <strong>Body Mass Index</strong> (BMI) (3,9), lower serum levels of <strong>total and LDL cholesterol</strong> (3) (LDL is \"the bad one\"), lower levels of C-reactive protein (10) (= show a lower lever of chronical inflammation), and higher <strong>insulin sensitivity</strong> (11) (this means they're less prone to diabetes). All this has been found studying people that were already vegetarian or vegan at the moment of the study.</p>\n\n<p>There are also experiments of people <strong>switching</strong> their diet to vegetarian or vegan for medical purpose, say get rid of <strong>diabetes or heart disease</strong>. A review of these successful experiments is <a href=\"https://lacucinadeibriganti.wordpress.com/articoli/diete-vegane-per-la-cura-delle-malattie-cardiovascolari-e-metaboliche/\">here</a>; basically people who switched to a low-fat lof-glycemic index vegan diet showed improvements in body weight, BMI, waist circumference, total and LDL cholesterol, triglycerides, glycemic control, insulin resistance, less need for drugs, reduction of cardiac events, reversal of heart disease. (12-16)</p>\n\n<p>If you want to read more scientific studies on vegetarianism you might also want to check these: 17-21.</p>\n\n<p>Finally I would like to add my personal experience (3 years vegetarian + 8 vegan): I feel better, my mind is more active, I can keep working or studying after lunch, I stopped having terrible pain in the intestine (probably due to putrefaction of meat during digestion) and my blood analysis are perfect.</p>\n\n<h2>References</h2>\n\n<ol>\n<li><p>Chang-Claude J, Frentzel-Beyme R. Dietary and Lifestyle Determinants of Mortality among German Vegetarians. Int J Epidemiol. 1993;22(2):228-236. doi:10.1093/ije/22.2.228.</p></li>\n<li><p>Thorogood M, Mann J, Appleby P, McPherson K. Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters. BMJ. 1994;308(6945):1667-1670. doi:10.1136/bmj.308.6945.1667.</p></li>\n<li><p>Key TJ, Fraser GE, Thorogood M, et al. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr. 1999;70(3):516S-524. Available at: <a href=\"http://ajcn.nutrition.org/content/70/3/516s.short\">http://ajcn.nutrition.org/content/70/3/516s.short</a>. Accessed May 15, 2015.</p></li>\n<li><p>Snowdon DA, Phillips RL. Does a vegetarian diet reduce the occurrence of diabetes? Am J Public Health. 1985;75(5):507-512. doi:10.2105/AJPH.75.5.507.</p></li>\n<li><p>Huang T, Yang B, Zheng J, Li G, Wahlqvist ML, Li D. Cardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic review. Ann Nutr Metab. 2012;60(4):233-40. doi:10.1159/000337301.</p></li>\n<li><p>Lanou AJ, Svenson B. Reduced cancer risk in vegetarians: an analysis of recent reports. Cancer Manag Res. 2010;3:1-8. doi:10.2147/CMR.S6910.</p></li>\n<li><p>Fu C-H, Yang CCH, Lin C-L, Kuo TBJ. Effects of long-term vegetarian diets on cardiovascular autonomic functions in healthy postmenopausal women. Am J Cardiol. 2006;97(3):380-3. doi:10.1016/j.amjcard.2005.08.057.</p></li>\n<li><p>Appleby PN, Davey GK, Key TJ. Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC-Oxford. Public Health Nutr. 2002;5(5):645-54. doi:10.1079/PHN2002332.</p></li>\n<li><p>Spencer EA, Appleby PN, Davey GK, Key TJ. Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int J Obes Relat Metab Disord. 2003;27(6):728-34. doi:10.1038/sj.ijo.0802300.</p></li>\n<li><p>Krajcovicova-Kudlackova M, Blazicek P. C-reactive protein and nutrition. Bratisl Lek Listy. 2005;106(11):345-7. Available at: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16541618\">http://www.ncbi.nlm.nih.gov/pubmed/16541618</a>. Accessed May 15, 2015.</p></li>\n<li><p>Kuo C-S, Lai N-S, Ho L-T, Lin C-L. Insulin sensitivity in Chinese ovo-lactovegetarians compared with omnivores. Eur J Clin Nutr. 2004;58(2):312-6. doi:10.1038/sj.ejcn.1601783. </p></li>\n<li><p>Barnard, N. D., Cohen, J., Jenkins, D. J. A., Turner-McGrievy, G., Gloede, L., Green, A., &amp; Ferdowsian, H. (2009). A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. The American Journal of Clinical Nutrition, 89(5), 1588S–1596S. doi:10.3945/ajcn.2009.26736H</p></li>\n<li><p>Ornish, D., Brown, S. E., Billings, J. H., Scherwitz, L. W., Armstrong, W. T., Ports, T. A., … Brand, R. J. (1990). Can lifestyle changes reverse coronary heart disease? The Lancet, 336(8708), 129–133. doi:10.1016/0140-6736(90)91656-U</p></li>\n<li><p>Esselstyn, C. B. (1999). Updating a 12-year experience with arrest and reversal therapy for coronary heart disease (an overdue requiem for palliative cardiology). The American Journal of Cardiology, 84(3), 339–341. doi:10.1016/S0002-9149(99)00290-8</p></li>\n<li><p>Jenkins, D. J. A., Kendall, C. W. C., Marchie, A., Faulkner, D. A., Wong, J. M. W., de Souza, R., … Connelly, P. W. (2003). Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. JAMA, 290(4), 502–10. doi:10.1001/jama.290.4.502</p></li>\n<li><p>Jenkins, D. J. A., Kendall, C. W. C., Faulkner, D., Vidgen, E., Trautwein, E. A., Parker, T. L., … Connelly, P. W. (2002). A dietary portfolio approach to cholesterol reduction: combined effects of plant sterols, vegetable proteins, and viscous fibers in hypercholesterolemia. Metabolism: Clinical and Experimental, 51(12), 1596–604. doi:10.1053/meta.2002.35578</p></li>\n<li><p>Craig, Winston, J., Mangels, Ann, R., Craig, W. J., &amp; Mangels, A. R. (2009). Position of the American Dietetic Association: vegetarian diets. Journal of the American Dietetic Association, 109(7), 1266–82. doi:10.1016/j.jada.2009.05.027</p></li>\n<li><p>Ferdowsian, H. R., &amp; Barnard, N. D. (2009). Effects of plant-based diets on plasma lipids. The American Journal of Cardiology, 104(7), 947–56. doi:10.1016/j.amjcard.2009.05.032</p></li>\n<li><p>Jenkins, D. J. A., Kendall, C. W., Marchie, A., Jenkins, A. L., Augustin, L. S., Ludwig, D. S., … Anderson, J. W. (2003). Type 2 diabetes and the vegetarian diet. Am J Clin Nutr, 78(3), 610S–616. Retrieved from <a href=\"http://ajcn.nutrition.org/content/78/3/610S.short\">http://ajcn.nutrition.org/content/78/3/610S.short</a></p></li>\n<li><p>Trapp, C. B., &amp; Barnard, N. D. (2010). Usefulness of vegetarian and vegan diets for treating type 2 diabetes. Current Diabetes Reports, 10(2), 152–8. doi:10.1007/s11892-010-0093-7</p></li>\n<li><p>Trapp, C., &amp; Levin, S. (2012). Preparing to Prescribe Plant-Based Diets for Diabetes Prevention and Treatment. Diabetes Spectrum, 25(1), 38–44. doi:10.2337/diaspect.25.1.38</p></li>\n</ol>\n", "score": 12 }, { "answer_id": 1165, "body": "<p>This is a question that cannot be answered by a simple yes or no.</p>\n\n<p>As a vegetarian for health purposes (who was a vegan for 1 year) I say that the human isn't supposed to be vegetarian, but rather an opportunistic omnivore. The fact that we can eat meat doesn't mean we have to.</p>\n\n<p>Most of people that went from non-vegetarian to vegetarian (no meat, no fish) felt better the following weeks, however the reasons could be numerous and ambiguous:</p>\n\n<ul>\n<li>Maybe they were eating <strong>too much</strong> meat until they stopped ?</li>\n<li>Maybe the meat they were buying was bad quality meat ?</li>\n</ul>\n\n<p>Anyway, most of meat and fish's nutrients we need to live healthy are proven to be in eggs and milk with enough quantities.</p>\n\n<p>Concerning the vegans (no eggs, no milk), the most recurrent problem is about the vitamin B12 that is very hardly obtained in vegan food, it can be found in some mushrooms, but in most cases you'll have to eat 4kg of that a day to fulfill your daily needs. It can also be found in some algaes and supplements like spirulina, but in that form it is nearly impossible for the body to be absorbed. Even though you might feel better the first year of veganism, you might be sick later on, even though some vegans never become sick.</p>\n\n<p>It also depends of the genes of each person. Some African ethnicities have evolved eating a lot of meat per day and still they remain healthier than most of people from Western countries. On the other hand, most Romans from the antiquity were eating less than 1kg of meat per month.</p>\n\n<p>I think that the best way to find how being vegetarian is good for you is to try it out by yourself, pay attention at how you feel, and have regular blood tests.</p>\n\n<p>Reference: <a href=\"http://chriskresser.com/what-everyone-especially-vegetarians-should-know-about-b12-deficiency\" rel=\"noreferrer\">What Everyone (Especially Vegetarians) Should Know About B12 Deficiency</a></p>\n", "score": 9 }, { "answer_id": 16403, "body": "<p>In 2013, as an already healthy athlete, I decided to stop eating meat, eggs, and dairy products and switch to a plant-based diet. Very soon thereafter, I noticed significant positive changes, realized what it truly meant to be a human being, and never looked back again.</p>\n\n<p>Note: Once you access any of the sources below, to see the supporting peer-reviewed articles, click on the sources cited tab.</p>\n\n<p>More energy (<a href=\"https://nutritionfacts.org/video/plant-based-diets-for-improved-mood-and-productivity/\" rel=\"nofollow noreferrer\">1</a>), better athletic performance (<a href=\"https://nutritionfacts.org/video/whole-beets-vs-juice-for-improving-athletic-performance/\" rel=\"nofollow noreferrer\">2</a>), faster muscle recovery (<a href=\"https://nutritionfacts.org/video/enhanced-athletic-recovery-without-undermining-adaptation/\" rel=\"nofollow noreferrer\">3</a>), less inflammation (<a href=\"https://nutritionfacts.org/video/reducing-muscle-fatigue-with-citrus/\" rel=\"nofollow noreferrer\">4</a>) (<a href=\"https://nutritionfacts.org/video/reducing-muscle-soreness-with-berries/\" rel=\"nofollow noreferrer\">5</a>), better and more frequent bowel movement (<a href=\"https://nutritionfacts.org/video/bowel-movement-frequency/\" rel=\"nofollow noreferrer\">6</a>) (<a href=\"https://nutritionfacts.org/video/bowels-of-the-earth/\" rel=\"nofollow noreferrer\">7</a>) (<a href=\"https://nutritionfacts.org/video/how-many-bowel-movements-should-you-have-every-day/\" rel=\"nofollow noreferrer\">8</a>), better blood sugar (<a href=\"https://nutritionfacts.org/video/how-not-to-die-from-diabetes/\" rel=\"nofollow noreferrer\">9</a>), less cholesterol (<a href=\"https://nutritionfacts.org/video/switching-from-beef-to-chicken-fish-may-not-lower-cholesterol/\" rel=\"nofollow noreferrer\">10</a>), lower risk of cancer or better said cancerlet (<a href=\"https://nutritionfacts.org/video/how-not-to-die-from-cancer/\" rel=\"nofollow noreferrer\">11</a>) (12 Latest-evidence based information on cancer can be found in chapter 3 of the book The China Study Revised and Expanded Edition) and much, much more.</p>\n\n<p>A vegetarian diet includes eggs and dairy products which, whether organic or not, still contain the same main components that meat does - cholesterol, high amounts of saturated fat, no fiber, and almost no antioxidants (<a href=\"https://nutritionfacts.org/video/antioxidant-power-of-plant-foods-versus-animal-foods/\" rel=\"nofollow noreferrer\">13</a>). So I only speak in the name of a whole food plant-based diet.</p>\n\n<p>Below is a picture comparing 500 calories of animal foods vs 500 calories of plant foods. Note the animal foods' cholesterol, high amounts of saturated fat, and no fiber. Data sources for the data in the picture:\n• USDA Nutrient Database. <a href=\"http://ndb.nal.usda.gov/ndb/\" rel=\"nofollow noreferrer\">http://ndb.nal.usda.gov/ndb/</a>\n• Holden JM, Eldridge AL, Beecher GR, et al. “Carotenoid content of U.S. foods: an update of the database.” J. Food Comp. Anal. 12 (1999): 169–196.\n• Campbell, T. Colin (2016) Chart 11.2 The China Study. Benbella Books. </p>\n\n<p><a href=\"https://i.stack.imgur.com/oeLjd.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/oeLjd.png\" alt=\"500 calories of plant foods vs 500 calories of animal foods\"></a></p>\n\n<p>Here is a picture that shows the food categories that I strive to consume on a daily basis. Each category, every day. And of course, remember to exercise and manage stress.</p>\n\n<p><a href=\"https://i.stack.imgur.com/ZjrKH.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/ZjrKH.jpg\" alt=\"proper plant-based diet\"></a></p>\n", "score": 5 } ]

[ "vegetarianism", "non-vegetarianism" ]

[ { "answer_id": 11130, "body": "<p>Your question has no correct answer. It is up to take the pain for a gain. What I would do is look for other times when I can build rapports.</p>\n<p>However, studies show that non-smokers exposed to second-hand smoke are at risk for many of the health problems associated with direct smoking.</p>\n<p>Risk on respiratory system: asthma, bronchitis and pneumonia.\nOther risks: lung cancer, heart disease and stroke.</p>\n<p><a href=\"https://en.wikipedia.org/wiki/Passive_smoking#Effects\" rel=\"nofollow noreferrer\">Passive smoking effects</a></p>\n<p><a href=\"https://health.stackexchange.com/a/443/8133\">A good explanation from SO</a></p>\n<p><a href=\"https://betobaccofree.hhs.gov/health-effects/smoking-health/#autoimmune\" rel=\"nofollow noreferrer\">Risk of autoimmune disease</a></p>\n<p><a href=\"https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/general_facts/\" rel=\"nofollow noreferrer\">Below Quotes are from the fact sheet</a></p>\n<blockquote>\n<p>It is estimated that secondhand smoke caused nearly 34,000 heart disease deaths each year during 2005–2009 among adult nonsmokers in the United States.</p>\n<p>Secondhand smoke exposure caused more than 7,300 lung cancer deaths each year during 2005–2009 among adult nonsmokers in the United States</p>\n<p>Since 1964, approximately 2,500,000 nonsmokers have died from health problems caused by exposure to secondhand smoke.</p>\n</blockquote>\n<p>If each cigarette lasts for 6 mins, if you inhale even 5% of smoke passively (which is very less than the real scenario) from each smoker.</p>\n<p>If you stand with 2 smokers for 24 mins in a day,\n2 smokers x 6 mins x 5% x 4 times = 240% per day i.e equivalent of 2.4 cigarette smokes.</p>\n<p>So in short <strong>Yes, it is highly risky</strong></p>\n", "score": 3 } ]

[ "smoking", "second-hand-smoke", "social" ]

[ { "answer_id": 4090, "body": "<p>A common medical myth is that cracking your knuckles causes arthritis, but is has been shown that cracking your knuckles, and popping your joints in general, will not raise your risk for developing arthritis.^{<a href=\"http://www.jabfm.org/content/24/2/169\" rel=\"noreferrer\">1</a>} It has also been shown to not cause degenerative joint disease in your hand joints in old age.^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1129752/pdf/westjmed00297-0049.pdf\" rel=\"noreferrer\">2</a>}</p>\n\n<p>However, cracking your knuckles does have some risks. One study from 1990,^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1004074/?tool=pubmed\" rel=\"noreferrer\">3</a>} showed that, while cracking your knuckles does not increase your risk of arthritis, it does impair your hand function. It was shown to lower grip strength and cause hand inflammation in habitual knuckle crackers. Acute injuries to ligaments in the knuckles as a result of cracking knuckles has also been recorded.^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10067714\" rel=\"noreferrer\">4</a>}</p>\n\n<p>There are no physical benefits to cracking your knuckles. It has been observed that there is a possibly perceived sense of therapeutic release when cracking your knuckles, which is most likely the reason that many people do it habitually. Though it is not incredibly dangerous, knuckle cracking is a habit that is probably best avoided.</p>\n\n<hr>\n\n<p>^{<a href=\"http://www.jabfm.org/content/24/2/169\" rel=\"noreferrer\">1: Knuckle Cracking and Hand Osteoarthritis</a>}</p>\n\n<p>^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1129752/pdf/westjmed00297-0049.pdf\" rel=\"noreferrer\">2: The Consequences of Habitual Knuckle Cracking</a>}</p>\n\n<p>^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1004074/?tool=pubmed\" rel=\"noreferrer\">3: Effect of habitual knuckle cracking on hand function.</a>}</p>\n\n<p>^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10067714\" rel=\"noreferrer\">4: Consequences of knuckle cracking: a report of two acute injuries.</a>}</p>\n\n<p>^{<a href=\"http://articles.mercola.com/sites/articles/archive/2014/11/08/cracking-knuckles-harmful.aspx\" rel=\"noreferrer\">Is Cracking Your Knuckles Harmful?</a>}</p>\n\n<p>^{<a href=\"http://www.hopkinsarthritis.org/arthritis-news/knuckle-cracking-q-a-from/\" rel=\"noreferrer\">Johns Hopkins Arthritis Center - Knuckle Cracking Q &amp; A</a>}</p>\n\n<p>^{<a href=\"http://www.medicalnewstoday.com/articles/259603.php\" rel=\"noreferrer\">Knuckles and Joints: Does Cracking Your Knuckles Cause Arthritis?</a>}</p>\n", "score": 9 } ]

[ "musculoskeletal-system" ]

[ { "answer_id": 13547, "body": "<p><strong>Because leprosy and multiple myeloma are conditions for which other treatment options are limited.</strong></p>\n\n<p>All treatments have side effects, some more debilitating than others. The trick with pharmacology is to balance the benefit of treatment with the hazards of the side effects.</p>\n\n<p>Take cancer chemotherapy. The drugs we use for cancer chemotherapy are <em>horrible</em> poisons. We literally use <a href=\"https://en.wikipedia.org/wiki/Nitrogen_mustard\" rel=\"noreferrer\">derivatives of chemical weapons</a> to treat cancer. Why do we deliberately poison cancer patients with what amounts to a weapon of mass destruction? Because if we don't, the cancer will kill them. </p>\n\n<p>In pharmacology there's a concept of a <a href=\"https://en.wikipedia.org/wiki/Therapeutic_index\" rel=\"noreferrer\">therapeutic window</a>. That is, there's a particular amount of compound that will cause death or other severe disability. There's another (hopefully lower) level of the compound that will effectively treat the disease. In treating, we hope to hit that middle ground: enough to treat the disease, but not enough to kill the patient.</p>\n\n<p>Different drugs have different therapeutic window. The window for over-the-counter drugs like asprin is rather large: the amount needed for severe side effects is many times higher than what people take to treat headaches. That's why we can allow untrained people to self-dose. (Though look at acetaminophen/paracetamol as an over-the-counter example where the window is not as large as it probably should be.) </p>\n\n<p>In contrast, the threaputic window for many chemotherapy drugs is rather narrow. To make sure we hit that window, they're typically dosed by licensed professionals in a very controlled environment.</p>\n\n<p>Back to thalidomide. The side effects of thalidomide are pretty severe. But to some extent they're controllable. If you scrupulously avoid exposing pregnant women or women who may become pregnant to thalidomide, you can avoid the teratogenic consequences. For the other consequences, you're back to the theraputic window: you want to hit a level of drug that is effective in treating the disease, but minimizes side effects.</p>\n\n<p>That's why thalidomide has been approved. It's a cost/benefit analysis. The approving authorities took a look at the hazards of leaving leprosy and multiple myeloma untreated (or treated with other methods) versus the hazards from exposure to thalidomide. On the whole, they felt that the risks of thalidomide could be mitigated enough that it was the \"lesser evil\" than leaving the diseases untreated.</p>\n\n<p>That said, if someone came out with a wonder drug that was as effective as thalidomide in treating these diseases but had fewer (or more benign) side effects, doctors would drop thalidomide like a hot potato, and the FDA might even revoke its approval. (Similar arguments hold for other potentially hazardous drugs like the nitrogen mustard chemotherapeutics.)</p>\n", "score": 41 }, { "answer_id": 13546, "body": "<p><a href=\"https://en.wikipedia.org/wiki/Thalidomide#Medical_uses\" rel=\"noreferrer\">Thalidomide</a> is used to treat, among other things, multiple myeloma. Since we know it has adverse effects for pregnant women, we simply don't give it to them.</p>\n\n<p>Almost all drugs have side effects of some kind. We don't ban aspirin or NSAIDS, even though those are all known to have issues with stomach bleeding, for example.</p>\n", "score": 9 } ]

[ "medications", "drug-metabolism" ]

[ { "answer_id": 131, "body": "<p>These are some reasons:</p>\n\n<ul>\n<li>Free sugars contribute to the overall energy density of diets. [<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12768890\">1</a>]</li>\n<li>Free sugars promote a positive energy balance. (= excess of energy intake) [<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12768890\">1</a>]</li>\n<li>Drinks that are rich in free sugars increase overall energy intake by\nreducing appetite control. [<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12768890\">1</a>]</li>\n<li>Fruit sugar is less cariogenic than refined sugar [<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12768890\">1</a>]</li>\n<li>Some sources talk about the potential damages of substances involved during refining of sugar: phosphoric acid [<a href=\"http://www.sugaraustralia.com.au/Industry.aspx?content=RefiningBusiness\">2</a>], calcium hydroxide [<a href=\"http://en.wikipedia.org/wiki/Sugarcane\">3</a>] and sulfur dioxide [<a href=\"http://en.wikipedia.org/wiki/Sugarcane\">3</a>]</li>\n<li>Finally free sugars and sweetened foods have higher glycemic index than naturally sweetened foods [<a href=\"http://www.health.harvard.edu/healthy-eating/glycemic_index_and_glycemic_load_for_100_foods\">4</a>]</li>\n</ul>\n\n<p>One more note in terms of <em>health</em>: free sugars have no minerals, vitamins nor fiber, that are usually contained in fruits and fruit juices.</p>\n", "score": 12 }, { "answer_id": 16362, "body": "<p>To directly answer your question: it is not. &quot;Natural&quot; sugar is no healthier than &quot;refined&quot; sugar, and sugar in fruits is no healthier than sugar in juice. Sugar molecules are sugar molecules, regardless of whether they are &quot;natural&quot; or &quot;refined.&quot; There is no difference.</p>\n<p>However, I believe the real question here is why the WHO is recommending one type of food over another, so I'll attempt to address this.</p>\n<p>The sugar is the same, but (1) the rest of the food that you eat with the sugar is different, so (2) your overall diet is different, (3) which leads to different health effects.</p>\n<p>(1) When you eat refined sugar you are typically not consuming nutrient-dense foods. A simple example is oranges vs. orange juice. Have you ever tried to eat three oranges? It's not easy. You have to chew a lot of pulp, which fills you up, and later on you may have bowel issues due to the large amount of fiber. These are natural mechanisms that help to prevent you from over-consuming oranges. However, if you instead squeeze these oranges, you get a glass of orange juice, which is easy to drink, and due to the lack of pulp it is easy to digest and does not fill you up.</p>\n<p>(2) A healthy diet has carbs, protein, fats, fiber, water, vitamins, minerals, and other nutrients, and if you eat a balanced mix of fruits, vegetables, meats, grains, nuts, and/or other &quot;natural&quot; foods, you can get a pretty good mix of these. If you consume a large quantity of refined foods, you'll get a lot of sugar, salt, and fat, but not much else, so you get a lot of calories but don't make much progress in your overall nutrient needs. This has the dual effects of excess calories and nutrient deficiency. You're starving (for nutrients) and over-consuming (sugar, salt, and fat) at the same time.</p>\n<p>(3) This unbalanced diet (heavy in sugar) leads to some health effects such as (a) excess weight gain, and (b) decreased insulin sensitivity.</p>\n<p>(3a) Fructose is generally processed by the liver, and it does not trigger the &quot;fullness&quot; feeling like glucose and other foods, leading to excess calorie consumption and weight gain. This extra body fat is associated with negative health effects.</p>\n<p>(3b) Insulin helps regulate blood sugar, but it can lose effectiveness, especially when blood sugar quickly and repeatedly rises to high levels. This is not just due to sugar, but starch and high glycemic index foods that easily break down into glucose. The amount matters, too. It's not just how fast the food gets converted to glucose but how much of it there is.</p>\n<p>Table sugar (sucrose) and corn syrup (including high fructose corn syrup) have both glucose and fructose, so you'll probably see both effects if you include enough refined foods in your diet.</p>\n<p>So, bottom line: refined foods have the same sugar chemicals, but the overall composition of the foods is skewed away from nutrients and toward sugar, which means the overall diet is out of balance, leading to over-consumption of calories, weight gain, and insulin resistance, which are associated with a number of health problems.</p>\n<p>References:<BR>\n[1] Maria Gadoy, &quot;What's More Nutritious, Orange Juice Or An Orange? It's Complicated&quot;, January 22, 2015, NPR, <a href=\"https://www.npr.org/sections/thesalt/2015/01/22/378920980/for-more-nutrients-drink-oj-or-eat-an-orange-it-s-not-so-clear-cut\" rel=\"noreferrer\">https://www.npr.org/sections/thesalt/2015/01/22/378920980/for-more-nutrients-drink-oj-or-eat-an-orange-it-s-not-so-clear-cut</a></p>\n<blockquote>\n<p>Interesting discussion about pros and cons of oranges vs. juice. Bottom line: cooking (pasteurizing) can release some nutrients better than fresh oranges, but juice has no fiber and does not fill you up.</p>\n</blockquote>\n<p>[2] DiNicolantonio JJ, Berger A. Added sugars drive nutrient and energy deficit in obesity: a new paradigm. Open Heart 2016;3:e000469. doi: 10.1136/openhrt-2016-000469\n<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975866/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975866/</a></p>\n<blockquote>\n<p>&quot;Not only do added sugars displace nutritionally superior foods in the diet, but they may also deplete nutrients from other foods that have been consumed, as well as from body stores, in order to enable their proper oxidation and liberate their calories as energy.&quot;<br></p>\n<p>&quot;Although edible, added sugars cannot be considered a ‘food’, nor can their consumption be equated to eating foods that contain natural amounts of sugar, but which also provide fibre, vitamins, minerals and other phytonutrients that combat oxidative stress produced by the small amounts of fructose present.&quot;</p>\n</blockquote>\n<p>[3] George A Bray; How bad is fructose?, The American Journal of Clinical Nutrition, Volume 86, Issue 4, 1 October 2007, Pages 895–896, <a href=\"https://doi.org/10.1093/ajcn/86.4.895\" rel=\"noreferrer\">https://doi.org/10.1093/ajcn/86.4.895</a><br></p>\n<blockquote>\n<p>&quot;When ingested by itself, fructose is poorly absorbed from the gastrointestinal tract, and it is almost entirely cleared by the liver&quot;<br></p>\n<p>&quot;Glucose stimulates insulin release from the isolated pancreas, but fructose does not.&quot;<br></p>\n<p>&quot;Fructose is metabolized, primarily in the liver, by phosphorylation on the 1-position, a process that bypasses the rate-limiting phosphofructokinase step (4). Hepatic metabolism of fructose thus favors lipogenesis, and it is not surprising that several studies have found changes in circulating lipids when subjects eat high-fructose diets&quot;</p>\n</blockquote>\n<p>[4] Peter J. Havel; Dietary Fructose: Implications for Dysregulation of Energy Homeostasis and Lipid/Carbohydrate Metabolism, Nutrition Reviews, Volume 63, Issue 5, 1 May 2005, Pages 133–157, <a href=\"https://doi.org/10.1111/j.1753-4887.2005.tb00132.x\" rel=\"noreferrer\">https://doi.org/10.1111/j.1753-4887.2005.tb00132.x</a></p>\n<blockquote>\n<p>&quot;Compared with glucose, the hepatic metabolism of fructose favors lipogenesis, which may contribute to hyperlipidemia and obesity. Fructose does not increase insulin and leptin or suppress ghrelin, which suggests an endocrine mechanism by which it induces a positive energy balance.&quot;</p>\n</blockquote>\n<p>[5] Boyd Swinburn, Gary Sacks, Eric Ravussin; Increased food energy supply is more than sufficient to explain the US epidemic of obesity, The American Journal of Clinical Nutrition, Volume 90, Issue 6, 1 December 2009, Pages 1453–1456, <a href=\"https://doi.org/10.3945/ajcn.2009.28595\" rel=\"noreferrer\">https://doi.org/10.3945/ajcn.2009.28595</a></p>\n<blockquote>\n<p>&quot;Increased energy intake appears to be more than sufficient to explain weight gain in the US population.&quot;</p>\n</blockquote>\n<p>[6] Sam Z. Sun, Mark W. Empie; Fructose metabolism in humans – what isotopic tracer studies tell us, Nutrition &amp; Metabolism 2012 9:89, October 2012.\n<a href=\"https://doi.org/10.1186/1743-7075-9-89\" rel=\"noreferrer\">https://doi.org/10.1186/1743-7075-9-89</a></p>\n<blockquote>\n<p>Detailed account of fructose metabolism.</p>\n</blockquote>\n<p>[7] Prediabetes &amp; Insulin Resistance, National Institute of Diabetes and Digestive and Kidney Diseases, NIH. <a href=\"https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance\" rel=\"noreferrer\">https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance</a></p>\n<blockquote>\n<p>&quot;Although the exact causes of insulin resistance are not completely understood, scientists think the major contributors to insulin resistance are excess weight and physical inactivity.&quot;</p>\n</blockquote>\n", "score": 10 } ]

[ "nutrition", "diet", "sugar" ]

[ { "answer_id": 563, "body": "<p>Note: The following is excerpted from an article written in 2005. For lay (Non trained) people, there are more updated recommendations. The following is an example of the process, not the current recommendations.</p>\n\n<blockquote>\n <p>To be effective, CPR must restore adequate coronary and cerebral blood flow. Interruptions in chest compressions lower coronary perfusion pressure and decrease rates of survival from cardiac arrest. In the first minutes of VF SCA, ventilation does not appear to be as important as chest compressions, but it does appear to contribute to survival from prolonged and asphyxial arrest. Certainly the ventilation rate needed to maintain a normal ventilation-perfusion ratio during CPR is much smaller than normal because pulmonary blood flow is low.</p>\n</blockquote>\n\n<p>That is one of the opening paragraphs <a href=\"http://circ.ahajournals.org/content/112/24_suppl/IV-206.full\">from this article</a> published on the American Heart Association (AHA) website from 2005, regarding CPR evaluation and recommended changes. (VF SCA = Ventricular Fibrillation Sudden Cardiac Arrest)</p>\n\n<p>As a summation, a group of scientists and heart experts (281 experts over 36 months) gathered to review all the study and epidemiological data regarding survival rate in witnessed SCA. They reviewed the (then) current survival rates, sequence and priorities in CPR to see how differences affected the survival rate. There are 57 articles cited throughout the article that are all listed with links.</p>\n\n<p>One of the biggest factors was that few people received early CPR, and those that did, it wasn't always effective CPR. Some of the factors that they found were that chest compressions were inadequately performed, slow, and often interrupted for too long for rescue breaths, especially among lay CPR performers (Non EMS trained). This resulted in inadequate cerebral blood flow and cardiac output.</p>\n\n<p>Once they determined that, the following excerpt explains how they evaluated the recommended changes (at that time, this is a 2005 publication.)</p>\n\n<blockquote>\n <p>Mathematical and animal models showed that matching of pulmonary blood flow and ventilation might be more appropriate at compression-ventilation ratios higher than 15:2. There was concern, however, particularly among pediatric experts, that inadequate ventilation rates could reduce survival from pediatric and asphyxial (eg, drowning) arrest. To achieve optimal compression rates and reduce the frequency of interruptions in compressions, a universal compression-ventilation ratio of 30:2 for all lone rescuers of victims from infancy (excluding newborns) through adulthood is recommended by consensus, based on integration of the best human, animal, manikin, and theoretical data available. The 30:2 ratio is recommended to simplify training in 1-rescuer or 2-rescuer CPR for adults and all lay rescuer resuscitation. A compression-ventilation ratio of 15:2 is recommended for 2-rescuer CPR (a skill taught chiefly to healthcare providers and lifeguards) for infants and children (to the onset of puberty). This recommendation will result in the delivery of more rescue breaths per minute of CPR to victims with a high prevalence of asphyxial arrest. </p>\n</blockquote>\n\n<p>So basically, a panel of experts gets together and reviews current literature and reports on survival from both field and hospital based sources. Along with that they review changes and practices that have been implemented (There is reference to early Automatic External Defibrillator {AED} devices being a key factor in survival rates) since the last recommendation. They pair this with animal and computer modeling to determine what should used for compression rates and compression/breath ratios.</p>\n\n<p>As far as the differences, I do not know how to account for those other than people using outdated information, or not following guidelines. Here in the United States, (as far as I know), all CPR certification falls under the guidelines of the AHA.</p>\n", "score": 10 }, { "answer_id": 336, "body": "<p>In Europe we use 30/2 for adults and 15/2 for children. </p>\n\n<p>For children heart problems are rare, so the focus lies on breathing (we also start with 5 breaths). With adults the focus lies on chest compressions, hence the double amount.</p>\n\n<p>There is a lot of research going on and as a result of the research, the guidelines are changed, each 5 years. (Last time the dept of the compression increased and the frequency went up.) We hope to receive the new guidelines in 2016.</p>\n\n<p>All ERC (European Resuscitation Council) trained instructors should use the same guidelines in their courses.</p>\n\n<p>The actual survival chance has increased a lot the last 20 years (if CPR is started with 6 minutes). Two pieces of equipment have helped. First the mobile phone (no delay in finding a phone so professional help can be summoned as soon as possible). And the use of the AED.</p>\n", "score": 5 } ]

[ "first-aid", "cpr", "research" ]

[ { "answer_id": 537, "body": "<p>Different hairs cells in inner ear (<a href=\"https://en.wikipedia.org/wiki/Cochlea\" rel=\"nofollow noreferrer\">cochlea</a>) vibrate in various ways in respond to different sound frequencies.</p>\n\n<p><img src=\"https://i.stack.imgur.com/9yNj7.gif\" alt=\"The hairs vibrate in various ways in respond to the resonance in the cochlear fluid.\"></p>\n\n<p>Small temporary changes or damages in the outer hair cells of the cochlea can trigger the emergence of tinnitus by increasing the gain of the central auditory system^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2686891/#B8\" rel=\"nofollow noreferrer\">2004</a>}.</p>\n\n<p>Most patients (both tinnitus and hearing loss) reports that the frequency of the tinnitus correlates with the severity and frequency characteristics of their hearing loss and that intensity of the tinnitus is usually less than 10dB above the patient's hearing threshold at that frequency^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2686891/#B6\" rel=\"nofollow noreferrer\">2004</a>}</p>\n\n<p>However the risk of hearing loss is not related to specific sound frequency, but rather to sound pressure (loudness) as it's stated in the article which you linked:</p>\n\n<blockquote>\n <p><strong>Exposure to loud noise.</strong> Loud noises, such as those from heavy equipment, chain saws and firearms, are common sources of noise-related hearing loss. Portable music devices, such as MP3 players or iPods, also can cause noise-related hearing loss if played loudly for long periods. Tinnitus caused by short-term exposure, such as attending a loud concert, usually goes away; long-term exposure to loud sound can cause permanent damage.</p>\n</blockquote>\n\n<p>Tinnitus is one of the most important symptoms that can signal the onset of acoustic trauma.</p>\n\n<p>Those exposed to over 85 decibels of sound continually are at a higher risk for acoustic trauma. In other words, the ear can be exposed to short periods in excess of 120dB without permanent harm (having discomfort and possibly pain), however long term exposure to sound levels over 80dB can cause permanent hearing loss^{<a href=\"https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&amp;p_id=9735\" rel=\"nofollow noreferrer\">OSHA</a>}.</p>\n\n<p>According to <a href=\"https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&amp;p_id=9735\" rel=\"nofollow noreferrer\">Occupational Safety &amp; Health Administration: Regulations (Standards - 29 CFR)</a>, these noise levels are permissible noise exposures:</p>\n\n<pre><code>______________________________________________________________\n |\n Duration per day, hours | Sound level dBA slow response\n____________________________|_________________________________\n |\n8...........................| 90\n6...........................| 92\n4...........................| 95\n3...........................| 97\n2...........................| 100\n1 1/2 ......................| 102\n1...........................| 105\n1/2 ........................| 110\n1/4 or less................| 115\n____________________________|________________________________\n</code></pre>\n\n<blockquote>\n <p>When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, rather than the individual effect of\n each.</p>\n \n <p>Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.</p>\n</blockquote>\n\n<p>Read more:</p>\n\n<ul>\n<li><a href=\"https://en.wikipedia.org/wiki/Tinnitus\" rel=\"nofollow noreferrer\">Tinnitus</a> and <a href=\"https://en.wikipedia.org/wiki/Noise-induced_hearing_loss\" rel=\"nofollow noreferrer\">NIHL</a> at Wikipedia</li>\n</ul>\n\n<p>See also: <a href=\"https://health.stackexchange.com/q/312/114\">When does the use of headphones become harmful?</a></p>\n", "score": 7 } ]

[ "hearing" ]

[ { "answer_id": 818, "body": "<p>A <em>very brief</em> review of an allergic response is in order so that the answer makes sense. Think of a linked chain of events here.</p>\n\n<p>An \"allergen\" is something a person is allergic to, e.g., cat dander or pollen. When someone is exposed to an allergen, they either become allergic or not.</p>\n\n<p>In a susceptible individual, something in the allergen (called an antigen, usually a protein of some kind) causes the person's immune system to produce an antibody (or Immunoglubin, in this case Immunoglobin E, or IgE) to the antigen, which then circulates throughout the entire system. The individual is now considered \"sensitized\". The IgE's bind to receptor sites on mast cell surfaces.</p>\n\n<p>When a sensitized individual is re-exposed to the antigen, the antigen binds to the IgE's changing the cell surface, triggering a response.</p>\n\n<p>Mast cells, found in connective tissues throughout the body - but especially in mucus membranes and skin - make and store a molecule called histamine. When the antigen binds to the IgE's on the mast cell, the cell is \"signalled\" to release (among other things) histamine, a molecule which causes local capillaries to swell and leak fluid: the typical runny/stuffy nose, red/itchy/watering eyes, etc.</p>\n\n<p>So that's a basic allergic response involving histamine.</p>\n\n<blockquote>\n <p>Is the antihistamine doing something regarding his immune's system reaction or is it doing something about the symptoms? How does it work?</p>\n</blockquote>\n\n<p>The antihistamine essentially blocks the effect of histamine on the capillaries. It doesn't decrease his immunity to the antigen (it doesn't stop IgE from being produced); it just treats the symptoms (stuffy nose, watery eyes, etc.)</p>\n\n<blockquote>\n <p>Will his immune system learn how to behave whilst taking antihistamines? Would the process of learning be better or worse for taking them?</p>\n</blockquote>\n\n<p>The antihistamine will have [little or]* no effect - either positive or negative - on his immune system. It is used only to make the allergic symptoms more tolerable.</p>\n\n<p><img src=\"https://i.stack.imgur.com/zBKyE.gif\" alt=\"enter image description here\"></p>\n\n<p>*_{The immune system is so incredibly complex, many things are still being worked out. I would not categorically rule out some kind of modulation, but for all intents and purposes, this is not what antihistamines are used for.}</p>\n\n<p>_{Image from <a href=\"http://www.theasthmacenter.org/index.php/disease_information/asthma/what_is_asthma/definition_of_asthma/mediator_release/\" rel=\"noreferrer\">The Asthma Center</a>}<br>\n_{<a href=\"http://www.jacionline.org/article/S0091-6749%2811%2901408-4/abstract\" rel=\"noreferrer\">Histamine and H1-antihistamines: Celebrating a century of progress</a>}<br>\n_{<a href=\"http://www.nature.com/nm/journal/v18/n5/full/nm.2755.html\" rel=\"noreferrer\">IgE and mast cells in allergic disease</a>}<br>\n_{<a href=\"http://www.ncbi.nlm.nih.gov/books/NBK27112/\" rel=\"noreferrer\">Janeway, <em>Immunobiology: The Immune System in Health and Disease. 5th edition</em></a>}<br>\n_{<a href=\"http://www.jacionline.org/article/S0091-6749%2811%2901408-4/abstract\" rel=\"noreferrer\">Histamine and H1-antihistamines: Celebrating a century of progress</a>}</p>\n", "score": 9 } ]

[ "allergy" ]