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[ { "answer_id": 9556, "body": "<p>Sleeping on the floor could be comfortable for some people who does such, but when you sleep on bed usually and eventually decide to sleep on the floor, it'll seem impossible due to body adaptation. </p>\n\n<p>It might take some weeks for such a person's body to adapt to sleeping on the floor. Let me use myself as a case study, I usually sleep on the bed, but a day arose when visitors came and I had to sleep on the floor, sincerely I found it hard to breathe because my ribs felt pressed against the floor.</p>\n\n<p>So yes sleeping on the floor can improve sleep quality but on the other hand, it can't improve sleep quality.</p>\n", "score": 1 }, { "answer_id": 5917, "body": "<p>Sleep quality is multi-factorial. It depends on several physical and mental factors which differ person to person. For instance patients with spinal problems are better to sleep in a supine position (sleep on the back) on a hard surface while allergic patients and children are better to sleep in a prone position (sleep on the stomach) because in this position mucosal secretions can run out easily and cause no breathing difficulty. So generally speaking, sleeping on the floor does not improve your sleep quality unless you have spinal or neck or muscular difficulties. For experiencing a good deep sleep it is suggested to have an early dinner, exercise daily, meditate before sleep and avoid caffeine and smocking.</p>\n", "score": 0 } ]

[ "sleep" ]

[ { "answer_id": 5719, "body": "<p><strong>Sleep irregularity</strong></p>\n\n<ol>\n<li>In children, values for lower sleep duration were found to be strongly associated with increased metabolic risk.</li>\n</ol>\n\n<blockquote>\n <p>Although obese children did not display radically different total weekly sleep durations, compared with their normal-weight counterparts, analyses of SV throughout the week revealed that obese children were less likely to experience “catch-up” sleep on weekends and the combination of shorter sleep duration and more-variable sleep patterns was associated with adverse metabolic outcomes. <a href=\"http://pediatrics.aappublications.org/content/127/2/e345\" rel=\"nofollow\">Source: Sleep Duration, Sleep Regularity, Body Weight, and Metabolic Homeostasis in School-aged Children</a></p>\n</blockquote>\n\n<ol start=\"2\">\n<li>Adequate sleep each day is noted to be very important for learning and memory.</li>\n</ol>\n\n<blockquote>\n <p>In the view of many researchers, evidence suggests that various sleep stages are involved in the consolidation of different types of memories and that being sleep deprived reduces one’s ability to learn. Although open questions (and debate) remain, the overall evidence suggests that adequate sleep each day is very important for learning and memory. <a href=\"http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/learning-memory\" rel=\"nofollow\">Source: Sleep, Learning, and Memory</a></p>\n</blockquote>\n\n<ol start=\"3\">\n<li>Several sleep hygiene practices are recommended <a href=\"http://healthysleep.med.harvard.edu/healthy/getting/overcoming/tips\" rel=\"nofollow\">here</a> to regulate one's sleep.</li>\n</ol>\n\n<p><strong>TL;DR:</strong> Adults are recommended to sleep at least for seven hours per night on a regular basis.</p>\n\n<blockquote>\n <p>Sleeping less than 7 hours per night on a regular basis is associated with adverse health outcomes, including weight gain and obesity, diabetes, hypertension, heart disease and stroke, depression, and increased risk of\n death. Sleeping less than 7 hours per night is also associated with impaired immune function, increased pain, impaired performance, increased errors, and greater risk of accidents. <a href=\"http://www.aasmnet.org/resources/pdf/pressroom/Adult-sleep-duration-consensus.pdf\" rel=\"nofollow\">Source: Recommended Amount of Sleep for a Healthy Adult</a></p>\n</blockquote>\n", "score": 4 }, { "answer_id": 4383, "body": "<p>As a Dr I can tell you that this has been accepted by scientific community, so it will affect on your brain, body physiology, metabolisms,behavior and even your gene expression.\nClearly, sleep is not only for the brain but also for the rest of the body.</p>\n\n<p>and there is tons of articles in this field just search in <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/\" rel=\"nofollow\">PubMed</a>.</p>\n\n<p>For example read these may help you:</p>\n\n<p><strong>If you want to read just one article as your answer i recommend to read this one</strong> <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3678519/\" rel=\"nofollow\">Metabolic Consequences in Humans of Prolonged Sleep Restriction Combined with Circadian Disruption</a> examined healthy volunteers over a 29-day period. They were made to sleep less and at varying bedtimes; sleeping patterns similar to those experienced by shift-workers.</p>\n\n<p>They found that the shift-like sleep patterns led to <strong>poorer glucose regulation and metabolism</strong>. The authors explained that eventually, over time, the raised risk of <strong>obesity</strong> and <strong>diabetes</strong> became apparent. </p>\n\n<p><a href=\"http://www.medscape.org/viewarticle/502825\" rel=\"nofollow\">Review:The Impact of Sleep Deprivation on Hormones and Metabolism</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/218642\" rel=\"nofollow\">Behavioral and psychophysiological correlates of irregularity in chronic sleep routine</a></p>\n\n<p>(sleep irregularity effect on physiological arousal indexes, psychomotor performance and subjective mood )</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3181883/\" rel=\"nofollow\">Sleep disorders as core symptoms of depression</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16120095\" rel=\"nofollow\">Effect of sleep deprivation on healing process </a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21350389\" rel=\"nofollow\">a review on cortisol level and sleep relation</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656315\" rel=\"nofollow\">review on sleep disturbance and suicide risk</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/21075236\" rel=\"nofollow\">Sleep deprivation Impact on cognitive performance</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778638/\" rel=\"nofollow\">Effects of sleep deprivation on neural functioning: an integrative review</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11744682\" rel=\"nofollow\">How sleep deprivation affects gene expression in the brain: a review of recent findings.</a></p>\n\n<p><a href=\"http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/emotions-cognitive\" rel=\"nofollow\">WebMD</a>( interesting facts to read)</p>\n\n<p>They are all valid scientific publication with standard experiments and a lot more articles that proves effect of sleep on behavior and health mental and physical.</p>\n", "score": 1 } ]

[ "sleep", "brain" ]

[ { "answer_id": 15121, "body": "<p>Occasional severe pain in the throat and chest after swallowing that radiates into the arms and feels like a heart attack (as mentioned in the question and one comment) fits the description of <strong>esophageal spasm</strong> (<a href=\"https://www.webmd.com/digestive-disorders/tc/esophageal-spasm-topic-overview#1\" rel=\"nofollow noreferrer\">WebMD</a>).</p>\n\n<p>The pain may last only for few seconds or minutes to hours (<a href=\"http://www.hon.ch/OESO/books/Vol_4_Prim_Motility/Articles/ART208.HTML\" rel=\"nofollow noreferrer\">OESO Knowledge</a>).</p>\n\n<p>The causes and risk factors are not well understood; they can include acid reflux, unusal anatomy, problems with intrinsic esophageal innervation, etc. (<a href=\"https://emedicine.medscape.com/article/174975-overview\" rel=\"nofollow noreferrer\">Emedicine</a>). The pain can be triggered by hot or cold beverages or stress, for example.</p>\n\n<p>One possible explanation: Swallowing air results in a different onset of the esophageal peristaltic wave than usually. In combination with an underlying muscle/nerve abnormality, this can trigger a muscle spasm.</p>\n\n<p>Diagnostic procedures include an X-ray with barrium swallow, esophageal manometry, etc.</p>\n\n<p>Various endoscopic or surgical procedures can help... </p>\n\n<p>Related terms: diffuse esophageal spasm, nutcracker or jackhammer esophageus, odynophagia. </p>\n", "score": 1 } ]

[ "pain", "gastroenterology", "water", "swallow-swallowing" ]

[ { "answer_id": 11687, "body": "<h2>Let's get a few things out of the way...</h2>\n<p>Sex is normal (<a href=\"http://link.springer.com/referenceworkentry/10.1007/978-3-540-29678-2_5370\" rel=\"noreferrer\">1</a>). Sexual desire and arousal are normal (<a href=\"http://www.bbc.com/future/story/20160217-what-is-a-normal-sex-life\" rel=\"noreferrer\">2</a>). Asexuality is normal (<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3965446/\" rel=\"noreferrer\">3</a>). Masturbation is normal (<a href=\"http://link.springer.com/referenceworkentry/10.1007/978-0-306-48113-0_261\" rel=\"noreferrer\">4</a>),(<a href=\"http://link.springer.com/referenceworkentry/10.1007/978-1-4419-1695-2_565\" rel=\"noreferrer\">5</a>). There is no problem whatsoever with these three things, although everyone blushes when they talk about them.</p>\n<h2>Is Masturbation healthy?</h2>\n<p><strong>Downsides</strong>:</p>\n<p>Masturbation is not risk free. It is about as dangerous as <em>chewing or walking</em> (<a href=\"http://www.webmd.com/men/guide/male-masturbation-5-things-you-didnt-know#1\" rel=\"noreferrer\">6</a>). Some side effects are irritated skin and ruptured penis, but only if you really, really, really overdo it (Once or twice a day is by far not overdoing it!).</p>\n<p><strong>Upsides</strong>:</p>\n<p>While masturbation does not have the health benefits sex has (<a href=\"http://www.webmd.com/men/guide/male-masturbation-5-things-you-didnt-know#1\" rel=\"noreferrer\">6</a>), there are some advantages to it:</p>\n<p>a) You get to know how your penis/vagina works. This will greatly benefit you when having sexual intercourse!</p>\n<p>b) Masturbation can help you relax and improve your mood; it won't resolve clinical depression but it can help you feel better if you're having a bad day, and it can help you forget about stressful events of the day and improve sleep.</p>\n<p>c) Masturbating can provide pain relief. Reports indicate that masturbation can help relieve menstrual cramps.</p>\n<p>d) Masturbation can help strengthen muscle tone in the pelvic and anal areas, which can reduce the chances of incontinence and uterine prolapse. (<a href=\"http://www.webmd.boots.com/sex-relationships/guide/women-masturbation\" rel=\"noreferrer\">7</a>)</p>\n<p>e) Masturbating men are less likely to develop prostate cancer. (<a href=\"http://www.menshealth.com/sex-women/health-and-sexual-benefits-of-masturbation\" rel=\"noreferrer\">8</a>)</p>\n<p><strong>Conclusion</strong>:\nUnless it <em>hurts</em> and <em>as long as you are comfortable with it and feel the desire</em>, masturbation is actually a good thing.</p>\n<h2>How much is too much?</h2>\n<p>As pointed out before, one can overdo it.\nThis article (<a href=\"http://sexuality.about.com/od/masturbation/a/masturbation1.htm\" rel=\"noreferrer\">9</a>) sums everything up quite neatly though:</p>\n<blockquote>\n<p>There is no amount of masturbation that is healthy or unhealthy. Masturbation isn’t like candy or eggs, there isn’t a &quot;recommended daily allowance&quot;, it means different things to different people, and we all use masturbation differently, in positive and negative ways. So this question needs to be answered on an individual basis, keeping in mind that very few of us actually masturbate in ways that are harmful to ourselves or others.</p>\n<p>Having said that, there are people whose masturbation is causing them distress and even pain (physical, emotional, psychological), and for those people it may make sense to talk with someone and sort our whether they are masturbating too much or whether they can adjust their feelings about masturbation to allow them to enjoy it more.</p>\n</blockquote>\n<h2>References and Sources</h2>\n<p>(1): <a href=\"http://link.springer.com/referenceworkentry/10.1007/978-3-540-29678-2_5370\" rel=\"noreferrer\">Encyclopedia of Neuroscience</a> - Sex<br />\n(2): <a href=\"http://www.bbc.com/future/story/20160217-what-is-a-normal-sex-life\" rel=\"noreferrer\">BBC Future</a> - What is a 'Normal' Sex Life?<br />\n(3): <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3965446/\" rel=\"noreferrer\">PLOS One</a> - Asexuality Development among Middle Aged and Older Men<br />\n(4): <a href=\"http://link.springer.com/referenceworkentry/10.1007/978-0-306-48113-0_261\" rel=\"noreferrer\">Women Health</a> - Masturbation<br />\n(5): <a href=\"http://link.springer.com/referenceworkentry/10.1007/978-1-4419-1695-2_565\" rel=\"noreferrer\">Encyclopedia of Adolescents</a> - Masturbation<br />\n(6): <a href=\"http://www.webmd.com/men/guide/male-masturbation-5-things-you-didnt-know#1\" rel=\"noreferrer\">WebMD</a> - Five things about male masturbation<br />\n(7): <a href=\"http://www.webmd.boots.com/sex-relationships/guide/women-masturbation\" rel=\"noreferrer\">WebMD</a> - Women Masturbation<br />\n(8): <a href=\"http://www.menshealth.com/sex-women/health-and-sexual-benefits-of-masturbation\" rel=\"noreferrer\">Men'sHealth</a> - Masturbation<br />\n(9): <a href=\"http://sexuality.about.com/od/masturbation/a/masturbation1.htm\" rel=\"noreferrer\">Sexuality.com</a> - Worried About Too Much Masturbation</p>\n<p>Might also be worth another look: <a href=\"https://health.stackexchange.com/a/11676/8212\">This great answer</a> by Chris on a very similar question.</p>\n", "score": 27 }, { "answer_id": 5512, "body": "<p>Since you have not been rendered blind, you can follow this <a href=\"http://www.nhs.uk/chq/Pages/3048.aspx?CategoryID=118\" rel=\"noreferrer\">link</a> which states that it is not intrinsically unhealthy unless it starts to interfere with the way you function socially or at work. In some people it intrudes into their public life and so then might considered an illness. Another form of harm is when it displaces normal sexual activity and some people find that they are then not able to engage in normal sexual activity with a partner due to habituation.</p>\n", "score": 8 }, { "answer_id": 22904, "body": "<p>I'm somewhat surprised stopping or drastically reducing your, um... fantasies, can lead to <a href=\"https://www.prostatitis.org/prosfaq.html\" rel=\"nofollow noreferrer\">Monk's Disease</a>.</p>\n", "score": 1 } ]

[ "sex", "masturbation" ]

[ { "answer_id": 21484, "body": "<p>One of the primary purposes of corticosteroids is to suppress immune activity and inflammation: that's exactly why they are used in asthma.</p>\n\n<p>Of course the immune system has an actual job besides causing nuisance inflammation: fighting infection.</p>\n\n<p>For some infections, the harm to the infected person caused by the immune reaction itself is worse than that of the pathogen itself, so steroids can help prevent damage or ease symptoms while the immune system continues to mount a response, without being <em>hyper</em>active.</p>\n\n<p>For others, immune suppression may be detrimental. </p>\n\n<p>Corticosteroids mediate the immune response by suppressing a variety of cytokines and increasing others, which influences activity circulating numbers of different immune cell populations. Cortisol binds the <a href=\"https://en.wikipedia.org/wiki/Glucocorticoid_receptor\" rel=\"noreferrer\">glucocorticoid receptor</a>, causing numerous changes in gene expression, many of which are associated with the immune system. From <a href=\"https://en.wikipedia.org/wiki/Cortisol#Immune_response\" rel=\"noreferrer\">Wikipedia</a>:</p>\n\n<blockquote>\n <p>(cortisol) inhibits production of interleukin (IL)-12, interferon (IFN)-gamma, IFN-alpha, and tumor-necrosis-factor (TNF)-alpha by antigen-presenting cells (APCs) and T helper (Th)1 cells, but upregulates IL-4, IL-10, and IL-13 by Th2 cells. This results in a shift toward a Th2 immune response rather than general immunosuppression. The activation of the stress system (and resulting increase in cortisol and Th2 shift) seen during an infection is believed to be a protective mechanism which prevents an over-activation of the inflammatory response.</p>\n</blockquote>\n\n<p>In other words, corticosteroids work by by suppressing the generalized killing/cleanup part of the immune system mediated by <a href=\"https://en.wikipedia.org/wiki/Macrophage\" rel=\"noreferrer\">macrophages</a> and <a href=\"https://en.wikipedia.org/wiki/Cytotoxic_T_cell\" rel=\"noreferrer\">CD8+ cells</a>, while preserving the <a href=\"https://en.wikipedia.org/wiki/B_cell\" rel=\"noreferrer\">B-cell</a> part of the immune system that produces specific antibodies and the <a href=\"https://en.wikipedia.org/wiki/Neutrophil\" rel=\"noreferrer\">neutrophils</a> that phagocytose antibody- and complement-bound pathogens.</p>\n\n<p>Immune reactions are incredibly complex, so some of these basics may be violated in certain circumstances (including prolonged rather than acute dosing), and I've left out a lot of the other related immune cells. See references below (and the Wikipedia pages linked above) for more:</p>\n\n<hr>\n\n<p>Cupps, T. R., &amp; Fauci, A. S. (1982). Corticosteroid‐mediated immunoregulation in man. Immunological reviews, 65(1), 133-155.</p>\n\n<p>McGee, S., &amp; Hirschmann, J. (2008). Use of corticosteroids in treating infectious diseases. Archives of internal medicine, 168(10), 1034-1046.</p>\n", "score": 20 }, { "answer_id": 21579, "body": "<p>The Lancet article you referenced in your question answered the questions you asked. In the trials of high dose corticosteroids used to treat SARS patients</p>\n\n<p>Corticosteroids use was: </p>\n\n<ul>\n<li>not associated with a difference in 90-day mortality (adjusted odds ratio 0·8, 95% CI 0·5–1·1; p=0·12)</li>\n<li>associated with delayed clearance of viral RNA from respiratory tract secretions (adjusted hazard ratio 0·4, 95% CI 0·2–0·7; p=0·0005).</li>\n<li>more likely to require mechanical ventilation, vasopressors, and renal replacement therapy</li>\n</ul>\n", "score": 2 } ]

[ "covid-19", "asthma", "virus", "steroids", "corticosteroids" ]

[ { "answer_id": 9, "body": "<p>Actually, in the case of most drugs, it has nothing to do with the immune system <em>per se</em>. Generally, drugs are either chemically modified (often in the liver) to make them inert, or excreted (either in the urine or the stool) thus removing them from the body. When the liver or the kidneys are not working properly, drugs fail to be excreted or digested, resulting in accumulation, which may be toxic.</p>\n", "score": 19 }, { "answer_id": 8, "body": "<p>Certainly not. By definition, it cannot break down poisons (at least not quickly enough) to stop the body being harmed or killed. In addition, it can not break down (or \"neutralize\") many radioactive substances. A famous example of this was the murder of <a href=\"http://en.wikipedia.org/wiki/Alexander_Litvinenko#Poisoning_and_death\">Alexander Litvinenko</a>:</p>\n\n<blockquote>\n <p>On 1 November 2006, Litvinenko suddenly fell ill and was hospitalised. His illness was later attributed to poisoning with radionuclide polonium-210 after the Health Protection Agency found significant amounts of the rare and highly toxic element in his body.</p>\n</blockquote>\n", "score": 14 }, { "answer_id": 7048, "body": "<p>First of all, it's typically liver and the kidneys responsible for removing unwanted chemicals from the body, not the immune system. It should be noted that liver and kidneys <strong>have no &quot;knowledge&quot; which chemical is &quot;bad&quot; and which is &quot;good&quot;</strong>. They have evolved to let some chemicals pass, react some chemicals etc. But there is plethora of compounds that had so little influence on evolutionary process, that we're not ready to handle them, since not being able to handle them was not selected against in the process of evolution.</p>\n<blockquote>\n<h3>So can the body break down anything?</h3>\n</blockquote>\n<p><strong>tl;dr: No, there are many chemical compounds that are not handled by human body ideally and that, even if there's enough time for the body to handle them, still cause major harm.</strong></p>\n<p>Not sure what breaking down exactly means here, but certainly there are some compounds that can get stuck in the body, notably heavy metals. Those and some others accumulate in the body, possibly but not necessarily causing harm in the future. Let's have some examples:</p>\n<h2>Bioaccumulation</h2>\n<p>Bioaccumulation is a process where organism (eg. you) absorbs certain chemical compound at faster rate than it excretes or processes it, which is probably what you meant by &quot;<em>breaking down</em>&quot;. See bellow some examples of such accumulation. Remember that the compound to be accumulated doesn't need to be exactly toxic, but as the poison is in the dose, as long as you accumulate something, it eventually <strong>will</strong> became toxic, should it even be water.</p>\n<h3>Silver</h3>\n<p>Silver is a heavy metal and was used as disinfection in the first half of 20th century^[1]. Silver accumulates in the human body, causing <a href=\"https://en.wikipedia.org/wiki/Argyria\" rel=\"nofollow noreferrer\">argyria</a>. This often happens to people who adhere to so-called &quot;alternative medicine&quot;, which includes promoting silver suspension as a cure to all kinds of diseases.^[2]</p>\n<h3>Lead</h3>\n<p>Lead is more dangerous than silver and is recognised as <a href=\"http://www.who.int/mediacentre/factsheets/fs379/en/\" rel=\"nofollow noreferrer\">important health problem by WHO</a>.</p>\n<h3>Other examples</h3>\n<p>I will defer listing of other <a href=\"https://en.wikipedia.org/wiki/Bioaccumulation#Examples\" rel=\"nofollow noreferrer\">examples on wikipedia</a>.</p>\n<h2>Toxification</h2>\n<p>As I said in the introduction, evolution didn't prepare liver and kidneys for many chemicals. Sometimes the attempt to react them starts the toxic reaction itself and it would be better if the chemical stayed in blood as-is and was excreted in urine. Such event is a type of <a href=\"https://en.wikipedia.org/wiki/Toxication\" rel=\"nofollow noreferrer\"><strong>toxification</strong></a>, toxification can generally occur anywhere, not just liver.</p>\n<h3>Methanol</h3>\n<p>Methanol is known as possible toxic component that can accidentally occur in alcoholic beverages. Methanol shares toxicity properties with ethanol, however on top of that, it is metabolized into formic acid in the liver. This is why, if there are no better alternatives, ethanol can be administered to prevent further methanol poisoning since it occupies the liver and therefore stops the toxification process. Bear in mind that this only works before the methanol was already turned into formic acid.^[3]</p>\n<h3>Arsenic</h3>\n<p>Apart from accumulating, arsenic also is oxidated in body which produces much more toxic arsenic (III) oxide which is the famous deadly poison.</p>\n<h3>Refferences:</h3>\n<ul>\n<li>[1] <a href=\"http://www.archive.org/stream/useofcolloidsinh00searuoft#page/70/mode/2up\" rel=\"nofollow noreferrer\">&quot;Chapter VIII: Germicides and Disinfectants&quot;. The Use of Colloids in Health and Disease</a></li>\n<li>[2] <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/10558603\" rel=\"nofollow noreferrer\">Over-the-counter drug products containing colloidal silver ingredients or silver salts</a></li>\n<li>[3] <a href=\"https://web.archive.org/web/20111005043548/http://www.antizol.com/mpoisono.htm\" rel=\"nofollow noreferrer\">Methanol poisoning overview</a></li>\n</ul>\n", "score": 2 }, { "answer_id": 430, "body": "<p>Any drug taken by mouth are being absorbed by the digestive system where a large amount may be destroyed by metabolic enzymes (<a href=\"http://en.wikipedia.org/wiki/First_pass_effect\" rel=\"nofollow\">first-pass metabolism</a>) and enters the <a href=\"http://en.wikipedia.org/wiki/Hepatic_portal_system\" rel=\"nofollow\">hepatic portal system</a>. Then it's carried through the <a href=\"http://en.wikipedia.org/wiki/Hepatic_portal_vein\" rel=\"nofollow\">portal vein</a> into the <a href=\"http://en.wikipedia.org/wiki/Liver\" rel=\"nofollow\">liver</a> to be absorbed into the bloodstream and excrete the waste through <a href=\"http://en.wikipedia.org/wiki/Bile\" rel=\"nofollow\">bile</a>. Some other bypass the liver, entering the blood directly. Only around 2-5% of the dose is excreted in an unchanged form in the urine.</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Biological_half-life\" rel=\"nofollow\">The biological half-life</a> of a substance refers to the body's cleansing through the function of kidneys and liver in addition to excretion functions to eliminate a substance from the body (time it takes for the blood plasma concentration of a substance to halve its steady-state).</p>\n\n<p>Here are the common prescription medications which has its high half-life:</p>\n\n<ul>\n<li>4–16 days: <a href=\"http://en.wikipedia.org/wiki/Fluoxetine\" rel=\"nofollow\">Fluoxetine</a>,</li>\n<li>5 weeks: <a href=\"http://en.wikipedia.org/wiki/Dutasteride\" rel=\"nofollow\">Dutasteride</a>,</li>\n<li>22-110 days: <a href=\"http://en.wikipedia.org/wiki/Amiodarone\" rel=\"nofollow\">Amiodarone</a></li>\n<li>5.5 months: <a href=\"http://en.wikipedia.org/wiki/Bedaquiline\" rel=\"nofollow\">Bedaquiline</a></li>\n</ul>\n\n<p>And here are the metals:</p>\n\n<ul>\n<li>Mercury (as methylmercury) in the body has a half-life of about 65 days.</li>\n<li>Lead in the blood has a half life of 28–36 days. In bone about 10 years.</li>\n<li>Cadmium in bone about 30 years.</li>\n<li>Plutonium in the liver about 40 years. Plutonium in bone about <strong>100 years</strong>.</li>\n</ul>\n\n<p>I hope that helps.</p>\n", "score": 1 } ]

[ "immune-system", "drug-metabolism" ]

[ { "answer_id": 614, "body": "<p>As you have noted, the \"paroxysmal\" stage of a clinical case of pertussis, which involves the rapid, exhausting coughing fits and the characteristic \"whoop\" at the end can often be extremely long. <a href=\"http://www.cdc.gov/pertussis/clinical/features.html\">While it usually lasts 1-6 weeks, it can persist for up to 10 weeks</a>, followed by a convalescent period.</p>\n\n<p>One reason for the long duration of the cough is that by the time one has reached that phase of disease, they are largely beyond the help of antibiotics, which <a href=\"http://www.prrjournal.com/article/S1526-0542(08)00041-9/abstract\">will not shorten the clinical course of the disease in infected patients</a>, but are intended to prevent its transmission to others.</p>\n\n<p>Additionally, the actual mechanism of action for pertussis helps making the coughing longer. <em>Bordetalla pertussis</em> infect the upper respiratory system and <a href=\"http://www.cdc.gov/pertussis/about/causes-transmission.html\">bind to the lining of your respiratory system</a>, decreasing the movement of your cilia, which serve to help clear mucous from your lungs. They also produce toxins which can cause inflammation and damage the cilia. As a result, even once the bacteria are dead, there is lingering damage to your respiratory system that will result in continued coughing.</p>\n", "score": 10 }, { "answer_id": 207, "body": "<p>As you mentioned, whooping cough is caused by Bordetella pertussis. It proves to be a very stubborn diseases especially in children. </p>\n\n<p><strong>Why this cough lasts so long?</strong></p>\n\n<p>There could be many reasons. </p>\n\n<p>Firstly, the bacteria attach themselves to the cells lining the airways and then gradually spread all over. The area of lungs and airway is quite large and it gives them all playground to multiple and have greater impact. </p>\n\n<p>Secondly, it is a specialty of this bacterium that <strong>even if it is treated and terminated</strong>, the coughing remains for long term. </p>\n\n<p><a href=\"http://www.patient.co.uk/health/whooping-cough-leaflet\" rel=\"noreferrer\">Patient.co.uk writes:</a></p>\n\n<blockquote>\n <p>Bordetella pertussis bacteria affect the lining of the airways in some way to cause symptoms (mainly a cough) to continue for a long time <strong><em>after the bacteria have gone.</em></strong></p>\n</blockquote>\n\n<p>This could be due to the damage they made and the healing time our body requires. I may not deny the theory that affected area might have some residuals of the microorganisms that might be causing 'irritation' to the throat that ultimately produces coughing. </p>\n", "score": 5 } ]

[ "infection", "cough" ]

[ { "answer_id": 143, "body": "<p>There are three main types of stretching that the general layman will be familiar with. There are a couple of others, but they are extreme techniques, and generally not used by the everyday athlete.</p>\n\n<ul>\n<li>Ballistic - The \"lean and bounce\" method, where you repeatedly bob back and forth in the stretch</li>\n<li>Dynamic - Mimics the motion of the activity in increasing amplitude</li>\n<li>Static - Traditional \"lean and hold\" type of stretching.</li>\n</ul>\n\n<p>Ballistic is old fashioned, and has been contraindicated for quite a while. One of the big risks is activating the stretch reflex in the tendon (This is what causes your knee to jerk when the doctor whacks you with the hammer), and this causes your muscle to try and tighten (shorten) at the same time you are actively lengthening it. This can produce tears, avulsions or tendon ruptures.</p>\n\n<p>Dynamic is recommended before activity, especially if you are doing an activity that requires great extremes of motion (Such as martial arts or gymnastics). This is simply doing the motions of the sport starting with slow, short movements and gradually increasing the range and power. Skips into bounds before running is one example of this. As evidenced <a href=\"http://journals.lww.com/nsca-jscr/Abstract/2008/11000/The_Acute_Effects_of_Dynamic_and_Ballistic.18.aspx\" rel=\"noreferrer\">by this study</a>, dynamic stretching before activity showed greater gains in jump power, where ballistic and static stretching did not show the same gains.</p>\n\n<p>Static should be done after activity if it is done. Several studies have shown that static stretching before activity (especially in power based activities) actually decreases performance. The main purpose of static stretching is to increase range of motion (ROM) in the area being stretched. <a href=\"http://saudeemovimento.net.br/wp-content/uploads/bsk-pdf-manager/402_EFFECT_OF_STATIC_AND_BALLISTIC_STRETCHING_ON.PDF\" rel=\"noreferrer\">This study</a> shows a decreased resistance to passive resistive torque (How far the joint can move before resistance begins), i.e. gains in flexibility with static where ballistic did not show the improvement. Ballistic did, however, reduce stiffness in the studied tendon (Achilles).</p>\n\n<p>There is currently no evidence that stretching will alleviate muscle pain, and while it is popular to do, not much evidence that it helps alleviate cramps, either. Static stretching (contrary to popular belief) has also not been proven to reduce injury rates (<a href=\"http://www.gytk.sote.hu/gyki/Oktatok/Horpet/Bozot_suggested_article.pdf\" rel=\"noreferrer\">As shown by this review article of the literature</a>) or assist with such things as delayed onset muscle soreness (DOMS), \"flush\" lactate out of the muscles, or anything. If it helps relax you, or if you need extreme ranges of motion for a specific sport, it can help, but other than that, there isn't much evidence for it to support performance increases.</p>\n\n<p>Also, since you mention that you play baseball, there is some evidence (Although I can't find the study at the moment) that preswing warmups should be done with a lightweight bat rather than a weighted bat, as it helps increase the following swing speeds.</p>\n\n<p>Addition: While reading through references, I did find some notations that ballistic stretching post exercise could possibly produce greater gains in flexibility, at the cost of a higher injury risk.</p>\n", "score": 14 }, { "answer_id": 189, "body": "<p>Here is my <a href=\"https://biology.stackexchange.com/a/30957/12909\">answer</a> from yesterday on Biology.SE. There is probably some overlap but I have linked articles with data available with my answer that may be of interest. As a note, the question on Bio was about warm showering to prepare for a sporting event. I am leaving the post as is since the information is still relevant and useful.</p>\n\n<hr>\n\n<p>I am going to address only the stretching portion of the question since some misinformation is out there. When you say stretching, I hope you mean dynamic as opposed to static stretching especially if you are about to compete in a sport. If you are referring to static stretching, taking a shower may be a better option then, but if you mean dynamic stretching, a shower will not provide a greater benefit.</p>\n\n<p>For peak performance, athletes or weekend warriors should use dynamic stretching prior to an event.</p>\n\n<blockquote>\n <p>In previous research it has been recommended to use dynamic stretching as the primary method of stretching pre-event warm-up before high speed, and power activities (Little &amp; Williams, 2004). The findings of this study agree with that recommendation for agility activities as well. This study supported the use of dynamic stretching in eliciting the greatest performance in agility movements by decreased T-Drill time. The findings\n of the current study are consistent with those of Fletcher and Jones (2004), and Young and Behm (2003) who determined that dynamic stretching elicits the best performance in power and high-speed activities <a href=\"http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1691&amp;context=etd\" rel=\"nofollow noreferrer\">[1]</a>. </p>\n</blockquote>\n\n<p>However, static stretching does not improve performance and can actually lead to injury.</p>\n\n<blockquote>\n <p>The current study found static stretching to have a negative effect on agility, and acceleration (Fletcher &amp; Jones, 2004; Nelson et al., 2005). As acceleration is a component of agility, these findings support those of Fletcher and Jones (2004) and Nelson et al. (2005). Agility also involves components of braking, and change of direction. Static stretching prior to agility activities was found to have a negative effect on agility performance <a href=\"http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1691&amp;context=etd\" rel=\"nofollow noreferrer\">[1]</a>. </p>\n</blockquote>\n\n<p>To read up on dynamic and static stretching as well as other types of stretching, I would recommend MIT's <a href=\"http://web.mit.edu/tkd/stretch/stretching_4.html\" rel=\"nofollow noreferrer\">Types of Stretching</a> page.</p>\n\n<p>Additionally, the references to my reference one provides many more useful articles to look into.</p>\n\n<ol>\n<li><a href=\"http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1691&amp;context=etd\" rel=\"nofollow noreferrer\">Static versus dynamic stretching effect on agility and performance</a></li>\n</ol>\n", "score": 7 }, { "answer_id": 115, "body": "<p>Although stretching is not the only answer, you should certainly do some pre-exercising. In a state of inaction, your muscles contract and tighten, and also lose heat. This makes them brittle and inert. Going straight into heavy exercise can cause significant damage, and so in going from inactive to fully active, you should ideally 'warm-up' with a more moderate set of exercises. This can include stretching, and should address all the muscle groups your main activity uses.</p>\n\n<p>Here are some references that agree with me:</p>\n\n<ul>\n<li><a href=\"http://www.ausport.gov.au/participating/coaches/tools/the_training_session/Warmup-Cooldown\" rel=\"nofollow\">Australian Sports Commission</a></li>\n<li><a href=\"http://www.sportsinjuryclinic.net/sports-specific/warm-up-cool-down\" rel=\"nofollow\">Sports Injury Clinic</a></li>\n</ul>\n\n<p>With running you can combine the warm-up into the run by starting off by almost walking.</p>\n", "score": 5 } ]

[ "muscle", "sports" ]

[ { "answer_id": 266, "body": "<p><strong><em>Short anwser</em></strong>: <a href=\"http://firstaid.about.com/od/injuriesathome/ht/06_burns.htm\">Never put butter, oil, etc</a>, on a burn. This would worsen the burn.</p>\n\n<p>Putting butter, oil, or anything else would trap heat and make the burn deeper. It would also make further treatment harder and would <a href=\"http://www.healthcommunities.com/burns/overview-of-burn-injuries.shtml\">make the risk of infection higher</a>:</p>\n\n<blockquote>\n <p><strong>Don’t apply burn ointments.</strong> Like butter (or mayonnaise), these ointments, usually oil-based, won’t relieve pain but instead will trap heat, slow down healing, and increase the risk of infection.</p>\n</blockquote>\n\n<p><strong><em>What to do instead</em>:</strong> Once it happens, a burn is actually \"cooking inside\", and this for a while after the exposure, so the first thing to do is to stop this internal reaction using flowing water.</p>\n\n<p>According to <a href=\"http://www.interieur.gouv.fr/content/download/36645/277100/file/PSC1_version%201.1.1.pdf\">official guidelines for general public in France</a> (page 12-14), and sticking to thermal burns here (not chemical nor electrical), you should:</p>\n\n<ol>\n<li><p>Quickly water the burn </p>\n\n<ul>\n<li>Act right after the burn if safely possible. (You are not supposed to put yourself in danger to save someone: this is the best way to end up with two victims instead of one)</li>\n<li>Put the burn under flowing water, between 15 and 25° Celsius. The tap is fine to to that, just keep in mind to keep the water pressure low enough not to press the burn.</li>\n<li>While watering, remove the clothes of the victim unless they adhere to the burn (should they adhere, don't pull on clothes).</li>\n</ul></li>\n<li><p>Evaluate the burn</p>\n\n<ul>\n<li>No blister or blister smaller that 1/2 of the victim's palm ; far from natural orifices ; not on the neck, face or joints ; just red, not black and white: this is a <strong>minor burn</strong></li>\n<li>Any burn that does not match the criteria above, or any large red area on a children, is a <strong>major burn</strong></li>\n</ul></li>\n<li><p>Should it be a <strong>minor burn</strong></p>\n\n<ul>\n<li>Keep on watering as long as the burn hurts and the victim doesn't feel cold. Not just a couple of seconds: 5 or 10 minutes is not surprising, it's actually fine. Watering is what prevents (more) blisters from appearing later on.</li>\n<li>Depending on the pain, aspect and victim's age: watch over the burn or ask a doctor or a physician. </li>\n<li>Don't pierce blisters should there be any. Cover them with a sterile plaster. </li>\n<li>Should blisters, fever, heat, pain, etc, appear later on, ask for medical advice.</li>\n</ul></li>\n<li><p>Should it be a <strong>major burn</strong> </p>\n\n<ul>\n<li>Call the medical emergency services, and, without hurrying (very important! Being calm is gaining time.)\n<ul>\n<li>Tell your name, phone number, current location,</li>\n<li>Tell this is for a burn, and tell the victim's gender and age</li>\n<li>Describe the result of the evaluation you made. </li>\n<li>They will guide you in accordance to the protocols applicable in your country. This guidance will certainly include watering, covering the victim if he/she feels cold...)</li>\n<li>Do NOT hang up the phone before they tell you to do so</li>\n</ul></li>\n<li>Keep on watering as instructed by the medical assistance.</li>\n<li>Make the victim to lie down in a way he/she cannot fall (floor, bed...). Sitting down is OK the victim has difficulties to breathe. The victim should NOT sit on a chair but on the ground to prevent him/her from falling. </li>\n<li>Protect the victim with a clean linen. The burnt body parts should remain visible.</li>\n<li>Watch over the victim until the arrival of the ambulance.</li>\n</ul></li>\n</ol>\n", "score": 17 } ]

[ "first-aid", "burns", "home-remedies" ]

[ { "answer_id": 511, "body": "<p>According to the Mayo Clininc, <strong>no</strong>. They write in their eye myths and facts section:</p>\n\n<blockquote>\n <p><strong>Myth: Wearing eyeglasses will weaken the eyes:</strong> The eyeglasses worn to correct nearsightedness, farsightedness, astigmatism, or presbyopia will not weaken the eyes any more than they will permanently \"cure\" these kinds of vision problems. Glasses are simply external optical aids that provide vision to people with blurred vision caused by refractive errors. Exceptions are the kinds of glasses given to children with crossed eyes (strabismus) or lazy eye (amblyopia). These glasses are used temporarily to help straighten the eyes or improve vision. Not wearing such glasses may lead to permanently defective vision <a href=\"http://mayoclinichealthsystem.org/locations/la-crosse/medical-services/ophthalmology/myths-and-facts\" rel=\"noreferrer\">[1]</a>.</p>\n</blockquote>\n", "score": 12 }, { "answer_id": 538, "body": "<p>Another explanation for the eye mis-focusing is that the problem is \"habitual strain,\" not the shape of the eye, and that glasses do nothing but exacerbate this strain. Instead, the cure is relaxation and exercises, via the <a href=\"https://en.wikipedia.org/wiki/Bates_method\" rel=\"nofollow\">Bates Method</a>. This explanation is still alive, despite a lack of scientific evidence that it works; Bates's seminal <a href=\"http://rads.stackoverflow.com/amzn/click/1484061748\" rel=\"nofollow\">Perfect Sight Without Glasses</a>, first published in 1920, is now in its 6th edition (2013).</p>\n\n<p>Anecdotally, though, glasses may cause the wearer to realize how bad their vision was before. And as with any impoverished sense, the brain will have learned to fill in the perceptual gaps automatically. New glasses-wearers may find their vision \"degrading\" as they lose their internalized accommodations, which are no longer needed.</p>\n", "score": 2 }, { "answer_id": 1173, "body": "<p>Essentially there are 3 eye conditions:</p>\n\n<ol>\n<li>Myopia (also called shortsightedness or nearsightedness). People with this condition struggle to see far things clearly.</li>\n<li>Hypermetropia (also know as longsightedness or farsightedness). People with this condition often - but not always - struggle to see close objects clearly.</li>\n<li>Astigmatism: where the eye is shaped like a rugby ball and the vision can be blurry at distance and near. </li>\n</ol>\n\n<p>(A fourth condition, Presbyopia, tends to affect older adults but isn't relevant in a discussion about glasses weakening the eyes).</p>\n\n<p>The only situation where wearing glasses may weaken the eyes is in the case of some young children who wear glasses to correct only small amounts of longsightedness. \nIf done at the right time and in the right manner by an Optometrist or other eye care professional these children can often gradually be weaned off their glasses with absolutely no adverse effects whereas if they are left alone and this is not done they may remain dependent on their glasses into adulthood. </p>\n", "score": 1 } ]

[ "eye" ]

[ { "answer_id": 1742, "body": "<p>I did not find any studies which would investigate that matter. Moreover, in 2008 Nillni and co-workers <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3254702/\" rel=\"nofollow\">(1)</a> stated:</p>\n\n<blockquote>\n <p>Surprisingly, although the expressed goal of breathing training is to correct hyperventilation, pCO2 has never been used as an outcome measure</p>\n</blockquote>\n\n<p>In a recent study <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22901344\" rel=\"nofollow\">(2)</a> it was concluded: </p>\n\n<blockquote>\n <p>Clinical improvement must have depended on elements common to both\n breathing therapies rather than on the effect of the therapies\n themselves on CO(2) levels.</p>\n</blockquote>\n\n<p>As so I would conclude that even in theoretical level there is very limited evidence for that intervention to be effective.</p>\n\n<p>But I would your use very different perspective. I bet that if you choose ten people out of the street and ask them \"What would you do if your friend had a panic attack?\" more than half would respond that they would give him/her a paper bag. The use of paper bag as an emergency intervention is a very common factoid. With this matter there exists a major <em>placebo</em> effect with that treatment. Use of paper bag as an emergency measure for person with a panic attack is very cost-effective without any potential side effects so it is an ideal \"intervention\". So I think we should not crave for solid evidence. Due to the factoid matter majority of people <em>think</em> it is an effective treatment and with comes a great placebo effect which should be definitely used due to the cost-effectiveness and safety. </p>\n", "score": 2 }, { "answer_id": 24691, "body": "<p>Breathing into a paper bag to control hyperventilation might improve hypocarbia, but should NOT be done because of the risks of hypoxia and death.</p>\n<p>This <a href=\"https://pubmed.ncbi.nlm.nih.gov/2499228/\" rel=\"nofollow noreferrer\">case report</a> shows that breathing into a paper bag during hyperventilation can reduce partial pressure of oxygen by up to 42 mmHg (normal 80-100mmHg) and can result in death.</p>\n<p>As answered by @arkiaamu, a better treatment would be <a href=\"https://www.hopkinsmedicine.org/health/conditions-and-diseases/hyperventilation\" rel=\"nofollow noreferrer\">reassurance, pursed lip breathing, and breathing exercises</a> to restore regular breathing pattern.</p>\n<p><strong>Case Report Source</strong>:\nCallaham M. Hypoxic hazards of traditional paper bag rebreathing in hyperventilating patients. Ann Emerg Med. 1989;18(6):622-628. doi:10.1016/s0196-0644(89)80515-3</p>\n", "score": 2 } ]

[ "effectiveness", "anxiety-disorders", "panic-attack", "hyperventilation", "carbon-dioxide" ]

[ { "answer_id": 3888, "body": "<p>The World Health Organization published a report entitled <a href=\"http://www.ncbi.nlm.nih.gov/books/NBK138218/pdf/Bookshelf_NBK138218.pdf\">Blood Donor Selection: Guidelines on Assessing Donor Suitability for Blood Donation</a>. Based on a review of scientific studies and other literature, it contains detailed recommendations for establishing blood donation programs, including which donors to accept or reject.</p>\n\n<p>It mentions several autoimmune diseases. From the non-communicable section (page 49), we have</p>\n\n<blockquote>\n <p><strong>5.1.4 Thrombocytopenia</strong><br>\n Individuals with thrombocytopenia should not be accepted as blood donors\n because of the risk of bleeding at the venepuncture site and because chronic\n thrombocytopenia may be associated with serious underlying haematological or\n other systemic disease. A past history of autoimmune thrombocytopenia is not\n a contraindication to blood donation, even if treated by splenectomy, provided\n that the prospective donor has been well for five years with no evidence of\n relapse (64).</p>\n</blockquote>\n\n<p>The specific reason for rejection here is twofold: The possibility of bleeding and of a secondary, more serious condition. The first risk, however, is common for all haematological disease. The section references a selection of guidelines from the UK Blood Transfusion &amp; Tissue Transplantation Services.</p>\n\n<p>There is a full section dedicated to \"Immunological diseases\" (which presumably encompasses autoimmune diseases) (page 57):</p>\n\n<blockquote>\n <p><strong>5.6 IMMUNOLOGICAL DISEASES</strong><br>\n Individuals with systemic immunological diseases are generally unwell and are\n therefore not suitable to donate blood. Donors should be questioned about severe\n allergy to materials used in blood collection, such as latex or skin disinfectant, so that contact with these materials can be avoided. Passive transfer of IgE by blood transfusion has been reported but does not alter acceptance criteria (129,130,131).</p>\n \n <p>While there is no evidence of harm resulting from blood donation by individuals with a history of anaphylaxis, the permanent deferral of such individuals is recommended as a precautionary measure (70).</p>\n</blockquote>\n\n<p>Note that the recommendation stems mostly from the assumption that these diseases are severe, and could thus cause serious harm to the recipients of these donors' blood. The referenced sources are three studies on the potential transferability of <a href=\"https://en.wikipedia.org/wiki/Immunoglobulin_E\">IgE</a>, and one general set of blood donor recommendations.</p>\n\n<p>A later section discusses general central nervous system diseases (page 58):</p>\n\n<blockquote>\n <p><strong>5.8 CENTRAL NERVOUS SYSTEM DISEASES</strong><br>\n Assessment of the suitability of prospective donors with central nervous system\n conditions should take into account the well-being of the donor and the risk of\n transfusion-transmission of variant Creutzfeldt-Jakob disease (vCJD).</p>\n</blockquote>\n\n<p>It is recommended that almost all donors with central nervous system diseases (epilepsy, multiple sclerosis, etc.) be deferred, for several reasons:</p>\n\n<ul>\n<li>A lack of full understanding of the cause of the disease (see the section on multiple sclerosis)</li>\n<li>A fear that blood donation could lead to adverse effects on the donor (see the section on epilepsy)</li>\n<li>The possibility of the transmission of variant Creutzfeldt-Jakob disease (vCJD).</li>\n</ul>\n\n<p>Some of these have not yet been supported by studies, although attempts have been made to prove/disprove them. The primary concern is that some variants of these diseases are not well-known enough, and there could be adverse effects that physicians are not aware of. This is a concern I've seen cited on various websites of blood donation programs.</p>\n\n<p>Finally, there is a generic section on medications (page 64). This harkens back to the deferral of some donors with thrombocytopenia, insofar as currently having the disease can make one ineligible for donation. In these cases, the medication could be transferred through the blood, thus possible harming the recipient:</p>\n\n<blockquote>\n <p><strong>6.2 MEDICATIONS</strong><br>\n Deferral criteria for medications taken by donors should take into account the\n underlying condition for which the medication is taken, the pharmacokinetic\n properties of the medication and the effect of the medication on the quality\n or safety of the donated blood (146,147,148). Donors should not omit regular\n medication in order to attend a blood donor session.</p>\n \n <p>There is no published evidence that medications in donated blood have caused\n adverse effects in a patient receiving transfusion, although it is unlikely that\n such events would be recognized. European Union legislation requires temporary\n deferral based on the “nature and mode of action” of the medication (149).</p>\n</blockquote>\n\n<p>Again, though this possibility has been studied, there is little evidence to back it up. Blood donation programs are advised to defer these potential donors in some cases out of caution.</p>\n\n<hr>\n\n<p>There are <em>some</em> autoimmune diseases which will not automatically prohibit blood donation. Among these are asthma and some cases of rheumatoid arthritis and hypothyroidism. These are the less severe autoimmune diseases, and they are also well-known and treatable, meaning that some of the risks mentioned earlier don't apply to them.</p>\n", "score": 15 } ]

[ "blood", "autoimmune-disease", "blood-donation" ]

[ { "answer_id": 8909, "body": "<p>I did some article browsing and here's what I found:</p>\n\n<ol>\n<li>Almost all of the articles I came across discussed the affect of general anesthesia on certain nerve tissues, ion channels, and receptors. I could not find a good overview or any peer reviewed articles covering the long-term clinical effects (what impact it actually has on the patient) of general anesthesia.</li>\n<li>Many of the studies are either in animals, in children, or in the elderly; not general population or a wide patient base.</li>\n<li>A general consensus seemed to be that the possible short term effects from anesthesia (malignant hyperthermia, hypotension, slowed respiratory rate) and the surgery itself lead to many more complications than any long term effects from general anesthesia.</li>\n</ol>\n\n<p>I did stumble across one fairly broad article which discussed cognitive decline in the elderly after uncomplicated general anesthesia. The syndrome is called Post-operative Cognitive Dysfunction (POCD). The article didn't seem to consider how many times patients had undergone anesthesia in their lives, but focused more on receiving anesthesia at an old age (85 or older).</p>\n\n<blockquote>\n <p>Lewis, M. C., and I. Nevo. \"Uncomplicated General Anesthesia in the Elderly Results in Cognitive Decline: Does Cognitive Decline Predict Morbidity and Mortality?\" Medical Hypothesis 68.3 (2007): 484-92. Science Direct. Web. 19 Aug. 2016. </p>\n</blockquote>\n\n<p>Here's another article that doesn't really answer your original question, but might be helpful nonetheless:\n<a href=\"http://healthland.time.com/2011/08/04/under-the-knife-study-shows-rising-death-rates-from-general-anesthesia/\" rel=\"nofollow\">General discussion TIME article</a></p>\n\n<p>So I couldn't find any articles addressing your specific situation, but hopefully some of this info can help you draw your own conclusions, and maybe someone else will have better luck article searching than I did.</p>\n", "score": 2 } ]

[ "medications", "surgery", "anesthesia" ]

[ { "answer_id": 3880, "body": "<p>Basically, most of what you suggested. </p>\n\n<p>One of the big risks of alcohol consumption is damage to the liver. Thus, if drinking a lot, don't do anything else that damages the liver, like taking medication that can itself lead to liver damage. The most common drug that this includes is acetaminophen (paracetamol). </p>\n\n<p>The next important thing is to get the alcohol to be delivered into the blood (and liver) slowly. That means eating before drinking, drinking slowly, and not taking any medication that worsens the effect of alcohol. </p>\n\n<p>And then comes reducing its effects and speeding up recovery. Drink enough additional fluids (water, juices, etc) before, during and after drinking alcohol. Get enough sleep and give your body time to recover. </p>\n\n<p>With regular alcohol consumption comes vitamin deficiencies. A multivitamin with folate, vitamin B6, thiamine, and vitamin A might help. Iron deficiency and anemia are common, getting enough iron in the diet or through a multivitamin can help with that. </p>\n\n<p>There are lots of things long-term alcohol abuse can cause that can't be treated like this, though. Seizures, nerve damage, pancreatitis, etc. </p>\n\n<p>All in all, I <strong>really, really</strong> recommend against it, but in this hypothetical scenario, the steps above might reduce the damage done to the body. </p>\n\n<p><strong>Sources</strong></p>\n\n<p><a href=\"http://www.liver.ca/liver-health/liver-disease-prevention/tips-for-healthy-liver/alcohol-consumption.aspx\">How to Protect Your Liver if You Drink Alcohol</a></p>\n\n<p><a href=\"http://mcwell.nd.edu/your-well-being/physical-well-being/alcohol/absorption-rate-factors/\">Absorption Rate Factors</a></p>\n\n<p><a href=\"http://www.nhs.uk/Livewell/alcohol/Pages/Hangovers.aspx\">NHS hangover cures</a></p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3544907\">Mechanisms of vitamin deficiencies in alcoholism</a></p>\n\n<p><a href=\"http://www.nhs.uk/conditions/alcohol-misuse/pages/risks.aspx\">Risks of alcohol misuse</a></p>\n\n<p><a href=\"http://www.m.webmd.com/a-to-z-guides/features/12-health-risks-of-chronic-heavy-drinking\">Health Risks of Alcohol</a></p>\n", "score": 14 } ]

[ "alcohol" ]

[ { "answer_id": 4310, "body": "<p><strong>It's unclear, but it's generally terrible for your survival odds.</strong></p>\n\n<p>The <a href=\"http://preventcancer.aicr.org/site/News2?page=NewsArticle&amp;id=13266&amp;news_iv_ctrl=0&amp;abbr=pr_hf_\" rel=\"noreferrer\">American Institute for Cancer Research</a> states quite bluntly that</p>\n\n<blockquote>\n <p>While underweight men and women have higher overall mortality rates than people of normal weight, this association is not seen in deaths resulting from cancer. In fact, rates of death from cancer among the underweight are not any higher than among people of normal weight. That said, some factors associated with being underweight can and do raise risk for certain cancers. Current and former smokers who are underweight have a higher risk of lung cancer. A diet lacking in basic nutrients can impair immune function and raise risk of several types of cancer.</p>\n</blockquote>\n\n<p>Notice the difference here between a risk of cancer from being underweight and a risk of cancer from other factors that can cause a person to be underweight. The two are vastly different things.</p>\n\n<p>Being underweight can lead to a higher mortality rate (see, for instance, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18519281\" rel=\"noreferrer\">Ringbäck et al. (2008)</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11520651\" rel=\"noreferrer\">Katzmarzyk et al. (2001)</a>, and <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10752793\" rel=\"noreferrer\">Visscher et al. (2000)</a>). However, this encompasses death via a variety of diseases, not just cancer. The jury is out on this, with some studies finding no correlation (<a href=\"http://jama.jamanetwork.com/article.aspx?articleid=209359\" rel=\"noreferrer\">Flegal et al. (2007)</a>) and some studies finding a possible inverse relationship between BMI and cancer at some ages (<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26634678\" rel=\"noreferrer\">Maasland et al. (2015)</a>, studying the risk of head-neck cancer).</p>\n\n<p>Regardless of the effect of low BMI on cancer risk, being underweight can drastically reduce your odds of survival if you <em>do</em> end up getting cancer.</p>\n\n<ul>\n<li><strong><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26277079\" rel=\"noreferrer\">Matsunaga et al. (2015)</a>:</strong> Underweight patients had a higher risk of cerebrovascular or pulmonary complications and mortality after surgery or related procedures for lung cancer while in a hospital. Often, their risk levels were twice as high as those for patients of normal weight or overweight patients.</li>\n<li><strong><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26298184\" rel=\"noreferrer\">Migita et al. (2015)</a>:</strong> Underweight people undergoing surgery for gastric cancer had a five-year survival rate of 66.6%, compared to 81.3% in people with normal BMI and 79.9% in overweight people.</li>\n<li><strong><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26008961\" rel=\"noreferrer\">Zogg et al. (2015)</a>:</strong> The risk-adjusted outcomes for underweight patients undergoing treatment or surgery for a variety of cancers \"consistently were worse\" than risk-adjusted outcomes for patients of normal BMI.</li>\n</ul>\n", "score": 6 } ]

[ "cancer", "weight" ]

[ { "answer_id": 7285, "body": "<p>As you mentioned in the side note, it really depends on the type of pill. Because there are chemical interactions between the food and the pill e.g. tetracycline and milk (tetracycline and calcium form complexes, thus inactivating the antibiotic).</p>\n\n<p>Generally the gastric pH is not so important for the drug uptake, as it happens in the small intestine. However some drugs can get destroyed in acid, therefore some pills have an acid resistant coating. \nThis coat is usually a weak acid. Since the gastric pH is very low (1-3) weak acids stay protonated, thus are not polar and can't be solved in water. Later in the duodenum the pH varies between 8-9, the coating weak acid deprotonates and dissolves. The drug is set free. This is the reason why you can't split all pills!</p>\n\n<p>The reason why you should eat some food with some medicaments is that they can irritate your gastric lining (e.g. diclofenac) and food serves as a buffer as it \"dilutes\" the medicament. Other substances need the food to function properly e.g. iron needs to be taken with orange juice or other vitamin c rich juices (the gastric acid oxidates <code>Fe2+ -&gt; Fe3+</code>, but <code>Fe3+</code> cannot be absorbed, therefore vitamin c is needed as a reduction agent).</p>\n\n<p>The question which food is the best can't really be answered as each patient is different. As long as the food does not harm the medication any food you like is good. Usually some crackers are enough, however if you start to feel stomach pain, eating more would be a good idea. Since most medicaments should be taken at a fixed time of the day, taking them 5 minutes after a regular meal is a good idea. </p>\n\n<p>However some food should not be eaten while taking medication because they induce/inhibit the cytochrome P450 system in the liver and therefore leading to insufficent or dangerous high blood levels of the medicamention.</p>\n\n<ul>\n<li><strong>grapefruit juice</strong> induces <a href=\"https://en.wikipedia.org/wiki/CYP3A4\" rel=\"nofollow noreferrer\">Cyt P450 3A4</a> which leads to sometimes greatly increased bioavailability of many medicaments and herbs (and the reverse for a few), and thus overdoses or underdoses.</li>\n</ul>\n", "score": 4 } ]

[ "medications", "digestion", "stomach" ]

[ { "answer_id": 12, "body": "<p>Calcium carbonate is largely insoluble in aqueous solutions; you need stomach acid to change it into calcium BIcarbonate, which is much more soluble.</p>\n\n<p>Calcium-fortified foods are generally fortified with other calcium salts which are more soluble, such as calcium acetate, calcium lactate, or calcium gluconate, unless the food is high in acid.</p>\n", "score": 11 } ]

[ "nutrition" ]

[ { "answer_id": 29, "body": "<p>There are several good tips to help avoid voice strain. </p>\n\n<ul>\n<li><p>Like you said, drink a lot of water (6-8 glasses a day); also, limit your intake of caffeinated drinks or alcoholic drinks, as they dry your throat</p></li>\n<li><p>When you are talking, support your voice with deep breaths, like singers have to; speaking from your diaphragm puts less stress on your voice and also make you talk clearer </p>\n\n<ul>\n<li>If you start to feel that you are getting voice strain, stop talking and just rest for a little while. </li>\n</ul></li>\n</ul>\n\n<hr>\n\n<p>_{<a href=\"http://www.nidcd.nih.gov/health/voice/pages/takingcare.aspx#4\" rel=\"nofollow\">Taking Care of Your Voice</a>}</p>\n", "score": 6 }, { "answer_id": 53, "body": "<p>One answer to this is <strong>give it some time</strong>. Your voice will get used to being used much more than it has in the past.</p>\n\n<p>When I became a teaching assistant I was suddenly using my voice to address large groups for long periods of time when I had previously only been using it for occasional conversation. My voice was raw for a few days at the beginning of the semester, but my body was able to adapt (I should note that this experience was fairly general among the group of graduate students I served with, not just me).</p>\n\n<p>Another possible approach might be <strong>ramp up</strong>. Don't go straight from not using your voice at all to using it all day. If it's possible to do part of your work by typing and the other with voice commands, alternate a little as your voice gets accustomed to heavier usage.</p>\n\n<p>Remedies for raw throat are discussed here in an article about drill sergeants, but they are anecdotal: <a href=\"https://www.militarytimes.com/2013/04/08/di-secrets-theres-a-human-side-to-these-larger-than-life-marines/\" rel=\"nofollow noreferrer\">https://www.militarytimes.com/2013/04/08/di-secrets-theres-a-human-side-to-these-larger-than-life-marines/</a>.</p>\n\n<p>[EDIT: previous link died. I found the article again, searching for \"the human side of these larger than life marines\"--here are the suggestions from the article:</p>\n\n<ul>\n<li>Same as sore throat remedy--honey, lemon, hot water</li>\n<li>Hot tea followed by a cold drink</li>\n<li>Pickle juice or lime juice mixed with salt\n]</li>\n</ul>\n", "score": 5 }, { "answer_id": 426, "body": "<p>When working with speech recognition systems, you should take the following steps to minimise strain:</p>\n\n<ul>\n<li>sit comfortably,\n<ul>\n<li>poor posture in sitting can lead to: swallowing, talking and breathing difficulties if your chest is slumped and unable to expand ^{<a href=\"http://www.nhs.uk/ipgmedia/national/multiple%20sclerosis%20trust/assets/areyousittingcomfortably.pdf\" rel=\"nofollow\">(source)</a>},</li>\n</ul></li>\n<li>speak at a normal pitch/volume,</li>\n<li>take breaks,</li>\n<li>drink regularly.</li>\n</ul>\n\n<p>Source: <a href=\"http://www.nhs.uk/accessibilityhelp/Factsheets/Voice-recognition-software-an-introduction.pdf\" rel=\"nofollow\">NHS: Voice Recognition Software - An Introduction</a></p>\n", "score": 5 }, { "answer_id": 13626, "body": "<p>The best thing you can do is visit a speech pathologist (aka a voice coach) who can work with you to make sure you are not stressing your vocal folds and other parts of the speech pathway.</p>\n", "score": 1 } ]

[ "voice", "computers" ]

[ { "answer_id": 42, "body": "<p>Ear tubes do many things to help ear infections. The most important things they do are draining the ear of fluid and ventilating the ear. Overall, this will help your child hear better. The tubes also stop fluid from building up behind the ear drum, which should help prevent the ear infections.</p>\n<h3>Stuff to watch out for</h3>\n<p>There is always the possibility of ear infections coming back after the 6-12 months that the tubes will be in. There is also a minor chance of hearing loss because of scarring of the ear drum. The tube can become blocked, stopping it from working. To help prevent these complications, you will have to routinely visit the doctor for a systems check.</p>\n<hr />\n<p><a href=\"http://www.webmd.com/cold-and-flu/ear-infection/tubes-for-ear-infections\" rel=\"noreferrer\">^{WebMD - Tubes for Ear Infections}</a></p>\n<p><a href=\"http://www.entnet.org/content/ear-tubes\" rel=\"noreferrer\">^{Ear Tubes}</a></p>\n", "score": 10 } ]

[ "otolaryngology", "infection", "treatment" ]

[ { "answer_id": 81, "body": "<p>This is debunked with little reference on <a href=\"http://www.snopes.com/food/ingredient/carrots.asp\" rel=\"noreferrer\">Snopes</a>. It is claimed there that the origin of the myth was deliberate misinformation to hide the use of a game-changing technology used by the RAF to shoot down German planes. This claim regarding the propaganda origin is sourced a bit better at the <a href=\"http://en.wikipedia.org/w/index.php?title=John_Cunningham_(RAF_officer)&amp;oldid=651180263#Propaganda\" rel=\"noreferrer\">Wikipedia article on one of the officers</a>.</p>\n\n<p>The grain-of-truth (which probably helps perpetuate the myth) is mentioned in the Snopes article as well and partially backed up at the (archived) <a href=\"https://web.archive.org/web/20070421214532/http://www.fruitsandveggiesmatter.gov/month/carrot.html\" rel=\"noreferrer\">CDC article on carrots</a> that they link to:</p>\n\n<blockquote>\n <p>Beta-carotene, which is found in the vegetable, may help reduce the risk of cataract and macular degeneration. However, it needs be pointed out that studies which have posited this link used doses of Vitamin A or beta-carotene that were higher than what is found in the standard diet. It would be quite difficult to eat the requisite number of carrots to match this level of intake. Also, among those who suffer a Vitamin A deficiency, nyctanopia (also known as nyctalopia or night blindness; the inability to see well in poor light) can be at least somewhat helped by adding carrots to the sufferer's diet.</p>\n</blockquote>\n", "score": 14 }, { "answer_id": 431, "body": "<p>This page on <a href=\"http://www.webmd.com/eye-health/fact-fiction-myths-about-eyes#0\" rel=\"noreferrer\">WebMd</a>\nhas an interesting section entitled &quot;Myths About Your Eyes and Vision.&quot;</p>\n<p>The relevant portion:</p>\n<blockquote>\n<p>Eating Carrots Will Improve Your Vision</p>\n<p>Fact: Carrots are high in vitamin A, a nutrient essential for good vision. Eating carrots will provide you with the small amount of vitamin A needed for good vision, but vitamin A isn't limited to rabbit food; it can also be found in milk, cheese, egg yolk, and liver.</p>\n</blockquote>\n<p>While the explanation is not as in-depth as the CDC article cited by @msouth, it appears to be a decent corroboration.</p>\n", "score": 7 } ]

[ "eye" ]

[ { "answer_id": 321, "body": "<p>How to stop or delay hair loss, it mainly depends on your cause and there many reasons of <a href=\"https://en.wikipedia.org/wiki/Hair_loss\" rel=\"noreferrer\">hair loss</a> (alopecia) as this can be caused by oxidative stress, alopecia areata, an autoimmune disorder, fungal infection, traumatic damage, iron deficiency and many more and it can occur anywhere and at any age.</p>\n<p>In general nutrients and antioxidants in food play an key role in body defence mechanism including hair growth. Antioxidants help to neutralize certain free radicals which have the potential to damage human cells and genetic material. They basically halting the oxidation reaction.</p>\n\n<h3>Antioxidants</h3>\n<ul>\n<li><p>Vitamin C &amp; E</p>\n<p>Is a potent antioxidant that help in maintaining healthy hair. It help to increase scalp circulation and oxygenation.</p>\n</li>\n<li><p>Polyphenol antioxidants^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569505/\" rel=\"noreferrer\">2005</a>}</p>\n<p>Polyphenols have many health benefits and their antioxidant properties promote hair growth. They're also photoprotective, radioprotective, anti-inflammatory and highly antioxidant.</p>\n<p>See also: <a href=\"https://en.wikipedia.org/wiki/Antioxidant_effect_of_polyphenols_and_natural_phenols\" rel=\"noreferrer\">Antioxidant effect of polyphenols and natural phenols</a></p>\n</li>\n<li><p>C60/EVOO (C60 dissolved in Extra Virgin Olive Oil)</p>\n<p>C60/EVOO is an strong anti-oxidant at intracellular level which results in better functioning mitochondria.</p>\n<p><a href=\"http://www.researchgate.net/publication/24021223_Fullerene_nanomaterials_potentiate_hair_g%20rowth/links/0c960528b84a79db7e000000.pdf\" rel=\"noreferrer\">Studies</a> in 2009 showed that fullerene nanomaterials potentiate hair growth:</p>\n<blockquote>\n<p>In SKH-1hairless mice fullerene derivatives given <strong>topically</strong> or subdermally markedly increased hair growth.</p>\n<p>The fullerenes also <strong>increased hair growth in human skin sections</strong> maintained in culture. These studies have wide-ranging implications for those conditions leading to hair loss, including alopecia, chemotherapy, and reactions to various chemicals.</p>\n<p>[...] <strong>We report that fullerene derivatives accelerate the growth of hair in mice and human skin.</strong> [...]</p>\n</blockquote>\n<p>Quote from Luna <a href=\"http://www.google.com.tr/patents/US20110003773\" rel=\"noreferrer\">US20110003773</a> patent:</p>\n<blockquote>\n<p>Using fullerenes to enhance and stimulate hair growth</p>\n<p>It has been discovered that <strong>fullerenes can stimulate hair growth</strong>, restore hair growth in areas of hair loss, and induce the formation of new hair follicles.</p>\n</blockquote>\n<p>Dr. Moussa has <a href=\"http://www.owndoc.com/pdf/C60-Fullerene.pdf\" rel=\"noreferrer\">studied</a> the effects of C60 on animals for 18 years and claim C60 in olive oil is safe and anti-toxic (has no toxicity effects).</p>\n<p>Quote from one <a href=\"http://www.longecity.org/forum/user/19769-turnbuckle/\" rel=\"noreferrer\">researcher</a> who was/is taking C60-EVOO orally/topically for over 3 years:</p>\n<blockquote>\n<p>Hair regrowth that filled in a patch in the back that had been thinning for thirty years and was bare in a spot about as big as my palm. (A Norwood 4 in the back and a 1.5 in the front).</p>\n<p>I have now seen further improvement by applying a small amount dissolved in 91% rubbing alcohol, applying it with a dropper to the scalp for a few days. So topical treatment may be better than oral for hair regrowth.</p>\n</blockquote>\n</li>\n</ul>\n", "score": 9 } ]

[ "hygiene", "alopecia", "hairloss" ]

[ { "answer_id": 150, "body": "<p><strong>LASIK</strong> is an acronym for <em>Laser-Assisted in situ Keratomileusis</em>, with <em>Keratomileusis</em> meaning surgical improvement of the cornea's refractive capabilities, i.e. usually to overcome the defects of myopia (short-sightedness), hyperopia (long-sightedness) and astigmatism (distorted vision).</p>\n<p>The process involves first cutting a corneal flap to allow access to the defective corneal tissue. This process involves keeping the eye open, and making an incision across the protective cornea tissue to form a flap. This is achieved via a suction ring. The flap is then lifted back (note that it is still connected to the rest of the eye). Lasers are then used to reshape the cornea tissue to remove the defects. The flap is pulled back over the cornea tissue and left to heal.</p>\n<p>The laser used operates using rapid pulses of low-energy-level ultraviolet light. The are other forms of eye surgery other than LASIK, but they depend more on the patients individual eye issues.</p>\n<p>These links from the U.S. Food and Drug Administration shows the processes involved.</p>\n<ul>\n<li><a href=\"https://www.fda.gov/medical-devices/surgery-devices/lasik\" rel=\"nofollow noreferrer\">https://www.fda.gov/medical-devices/surgery-devices/lasik</a> (with a video explaining the risks)</li>\n<li><a href=\"https://www.fda.gov/medical-devices/lasik/lasik-faqs-frequently-asked-questions\" rel=\"nofollow noreferrer\">https://www.fda.gov/medical-devices/lasik/lasik-faqs-frequently-asked-questions</a></li>\n</ul>\n", "score": 10 } ]

[ "eye", "surgery", "opthalmology", "lasik" ]

[ { "answer_id": 258, "body": "<ul>\n<li><h3>Walking</h3>\n\n<ul>\n<li>Several studies have been done on the effects of walking and high blood pressure</li>\n<li>One Korean study<a href=\"http://synapse.koreamed.org/DOIx.php?id=10.15384/kjhp.2014.14.2.67\">¹</a> had 23 men with hypertension; they found that taking a 40 minute walk helped to reduce the blood pressure in the test subjects</li>\n</ul></li>\n<li><h3>Eating<a href=\"http://www.webmd.com/hypertension-high-blood-pressure/high-blood-pressure-diet\">²</a></h3>\n\n<ul>\n<li>Avoid salt (sodium) because it puts higher strain on your blood vessels, which raises your blood pressure</li>\n<li>Eat fruits and vegetables (apples, bananas, grapes, broccoli, carrots) because they contain potassium, magnesium, and fiber, which all help to control blood pressure, and they are also low in sodium</li>\n<li>Other good foods to eat are nuts, legumes, and poultry</li>\n</ul></li>\n<li><h3>Relaxation<a href=\"http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/PreventionTreatmentofHighBloodPressure/Stress-and-Blood-Pressure_UCM_301883_Article.jsp\">³</a></h3>\n\n<ul>\n<li>Stress is an indirect cause of high blood pressure; sometimes people cope with stress by doing unhealthy things like smoking or eating junk food, which can raise blood pressure</li>\n<li>Meditation is a great way to reduce stress</li>\n<li>Get more sleep</li>\n</ul></li>\n</ul>\n\n<hr>\n\n<p>^{[<a href=\"http://synapse.koreamed.org/DOIx.php?id=10.15384/kjhp.2014.14.2.67\">1</a>] <a href=\"http://synapse.koreamed.org/DOIx.php?id=10.15384/kjhp.2014.14.2.67\">The Effect Size Analysis of Exercise on Body Composition, Blood Pressure, and Physical Fitness in Korean Adults</a>}</p>\n\n<p>^{[<a href=\"http://www.webmd.com/hypertension-high-blood-pressure/high-blood-pressure-diet\">2</a>] <a href=\"http://www.webmd.com/hypertension-high-blood-pressure/high-blood-pressure-diet\">WebMD - High Blood Pressure Diet</a>}</p>\n\n<p>^{[<a href=\"http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/PreventionTreatmentofHighBloodPressure/Stress-and-Blood-Pressure_UCM_301883_Article.jsp\">3</a>] <a href=\"http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/PreventionTreatmentofHighBloodPressure/Stress-and-Blood-Pressure_UCM_301883_Article.jsp\">American Heart Association - Stress and Blood Pressure</a>}</p>\n", "score": 13 }, { "answer_id": 8779, "body": "<p>There are only currently two main supplements you can take to help reduce blood pressure, beyond the advice of just <strong>exercising more</strong>, <strong>eating healthy</strong> and <strong>relaxing</strong>.</p>\n<h1><a href=\"https://examine.com/supplements/hibiscus-sabdariffa/#hem-blood-pressure\" rel=\"nofollow noreferrer\">Hibiscus Sabdariffa</a></h1>\n<p>Hibiscus Sabdariffa (Roselle or Sour Tea) is a tea where the usually dark colored flowers are used to brew. It appears to inhibit carbohydrate absorption to a degree and appears to be effective in reducing blood pressure.</p>\n<p>Dosage: 10mg</p>\n<p>The 10mg is in reference to the total anthocyanin content, which appears to be the active ingredient; the exact quantity of anthocyanins should be listed on the label, or can be achieved with 5-10g of the flower's calyx steeped in tea. Tea can be used in lieu of supplementation, and should be similarly effective.</p>\n<h1><a href=\"https://examine.com/supplements/garlic/#hem-blood-pressure\" rel=\"nofollow noreferrer\">Garlic</a></h1>\n<p>Garlic (Allium sativum) is a food product that can improve immunity and cardiovascular health. Garlic supplementation appears to reduce blood pressure, and the magnitude is quite respectable in persons with hypertension (around 10 points systolic or 8-10%) whereas there is a smaller but present reduction in persons with normal blood pressure.</p>\n", "score": 1 } ]

[ "blood-pressure", "hypertension" ]

[ { "answer_id": 329, "body": "<p>Does coffee inhibit the absorption of iron? The answer appears to be yes (see links and references below). So does tea. Note that this does not have to do with caffeine, but rather polyphenols, phytates found in them. So, my answer would be that both regular coffee and decaf coffee inhibit iron, but I don't know whether one does so more than the other. Also, if you add milk to your coffee, that may also have some effect, because calcium inhibits iron absorption. </p>\n\n<p>It also depends on whether it's heme iron (mostly from animals) or non-heme iron (from plant sources, iron fortified foods). This matters if you eat primarily a vegetarian diet, because the recommended intake for non-heme iron is 1.8 times, compared to those who eat meat . <a href=\"http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/\">NIH's Iron\nDietary Supplement Fact Sheet </a> compiled a great literature review on iron intake. See also <a href=\"http://www.cdc.gov/nutrition/everyone/basics/vitamins/iron.html\">CDC.</a></p>\n\n<p>References </p>\n\n<p>Hurrell RF, Reddy M, Cook JD. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr. 1999;81:289–95.</p>\n\n<p>Layrisse M1, García-Casal MN, Solano L, Barón MA, Arguello F, Llovera D, Ramírez J, Leets I, Tropper E. Iron bioavailability in humans from breakfasts enriched with iron bis-glycine chelate, phytates and polyphenols. J Nutr. 2000 Sep;130(9):2195-9.</p>\n\n<p>Zijp IM1, Korver O, Tijburg LB. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr. 2000 Sep;40(5):371-98.</p>\n", "score": 8 } ]

[ "nutrition", "caffeine", "iron" ]

[ { "answer_id": 446, "body": "<p>High levels of alcohol consumption during pregnancy can be harmful which can develop physical and mental defects in a fetus.</p>\n\n<p>When you drink, alcohol passes from your blood through <a href=\"http://en.wikipedia.org/wiki/Placenta\" rel=\"noreferrer\">placenta</a> to a baby and can stunt fetal growth, facial deformities, damage neurons and brain structures which can result in intellectual disability and also cause other physical damage. A baby's liver is one of the last organs to develop fully and doesn't mature until the latter stages of pregnancy, so cannot process alcohol. So if you drink at any time during your pregnancy, the alcohol can affect your baby.</p>\n\n<p>While the effects attributed to alcohol are still more common in heavier drinkers, they seem to happen at much lower drinking levels than seen in those with FAS.</p>\n\n<p>The most severe of the alcohol-related conditions (due to heavy drinking) is <a href=\"http://en.wikipedia.org/wiki/Fetal_alcohol_syndrome\" rel=\"noreferrer\">Foetal Alcohol Syndrome (FAS)</a>. It causes: </p>\n\n<ul>\n<li>Problems with physical and emotional development.</li>\n<li>Hyperactivity and poor attention span.</li>\n<li>Poor short-term memory.</li>\n</ul>\n\n<p>Baby with Fetal Alcohol Syndrome:</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/File:Photo_of_baby_with_FAS.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/PHRPim.jpg\" alt=\"Baby with Fetal Alcohol Syndrome\"></a></p>\n\n<p>^{Image credits: <a href=\"http://www.fasstar.com/\" rel=\"noreferrer\">Wiki / Teresa Kellerman</a>}</p>\n\n<blockquote>\n <p>Children with FAS have distinct facial features including: small and narrow eyes, a small head, a smooth area between the nose and the lips and a thin upper lip.</p>\n</blockquote>\n\n<p>They also show the following symptoms:</p>\n\n<ul>\n<li>Hearing and ear problems.</li>\n<li>Mouth, teeth and facial problems.</li>\n<li>Weak immune system.</li>\n<li>Epilepsy.</li>\n<li>Liver damage.</li>\n<li>Kidney and heart defects.</li>\n<li>Cerebral palsy and other muscular problems.</li>\n<li>Height and weight issues.</li>\n<li>Hormonal disorders.</li>\n</ul>\n\n<p>^{Source: <a href=\"https://www.drinkaware.co.uk/check-the-facts/health-effects-of-alcohol/fertility-and-pregnancy/foetal-alcohol-syndrome-(fas)/\" rel=\"noreferrer\">Drinkaware</a>}</p>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Fetal_alcohol_spectrum_disorder\" rel=\"noreferrer\">FASD</a> (Foetal Alcohol Spectrum Disorders) is the umbrella term used to describe the conditions that occur in people who have been diagnosed with some, but not all, of the symptoms of FAS. It is more difficult for a specialist to diagnose FASD than it is FAS, because children with FASD may not have facial deformities. However the following symptoms can show up:</p>\n\n<ul>\n<li>Learning difficulties.</li>\n<li>Problems with language.</li>\n<li>Lack of appropriate social boundaries (such as over friendliness with strangers).</li>\n<li>Poor short term memory.</li>\n<li>Inability to grasp instructions.</li>\n<li>Failure to learn from the consequences of their actions.</li>\n<li>Egocentricity.</li>\n<li>Mixing reality and fiction.</li>\n<li>Difficulty with group social interaction.</li>\n<li>Poor problem solving and planning.</li>\n<li>Hyperactivity and poor attention.</li>\n<li>Poor coordination.</li>\n</ul>\n\n<hr>\n\n<p>The UK's Department of Health recommends that if you're pregnant you should avoid alcohol altogether.</p>\n\n<p>The National Institute for Health and Care Excellence (NICE), which advises healthcare professionals (GPs and nurses), advice pregnant women to:</p>\n\n<ul>\n<li>not to drink alcohol in the first three months of pregnancy, because there may be an increased risk of miscarriage,</li>\n<li>if they choose to drink alcohol while they are pregnant, they should drink no more than one or two units of alcohol, once or twice a week as there is uncertainty about how much alcohol is safe to drink in pregnancy, but if a low level is consumed there is no evidence of harm to an unborn baby,</li>\n<li>if women want to avoid all possible alcohol-related risks, they should not drink alcohol during pregnancy, as the evidence on this is limited.</li>\n</ul>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.nhs.uk/chq/Pages/2270.aspx?CategoryID=54\" rel=\"noreferrer\">Can I drink alcohol if I’m pregnant?</a> at NHS</li>\n<li><a href=\"http://www.nhs.uk/chq/Pages/958.aspx\" rel=\"noreferrer\">Is it safe to drink alcohol while breastfeeding?</a> at NHS</li>\n<li><a href=\"http://www.nhs.uk/conditions/pregnancy-and-baby/pages/alcohol-medicines-drugs-pregnant.aspx\" rel=\"noreferrer\">Alcohol in pregnancy</a> at NHS</li>\n<li><a href=\"https://www.drinkaware.co.uk/check-the-facts/health-effects-of-alcohol/fertility-and-pregnancy/foetal-alcohol-syndrome-(fas)/\" rel=\"noreferrer\">Foetal Alcohol Syndrome (FAS)</a> at Drinkaware</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Fetal_alcohol_syndrome\" rel=\"noreferrer\">Fetal alcohol syndrome</a> (FAS) at Wikipedia</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Fetal_alcohol_spectrum_disorder\" rel=\"noreferrer\">Fetal alcohol spectrum disorder</a> (FASD) at Wikipedia</li>\n<li><a href=\"http://www.nhs.uk/conditions/alcohol-misuse/Pages/Introduction.aspx\" rel=\"noreferrer\">Alcohol misuse</a> at NHS</li>\n<li><a href=\"http://www.nhs.uk/conditions/pregnancy-and-baby/pages/alcohol-medicines-drugs-pregnant.aspx#close\" rel=\"noreferrer\">Alcohol and drugs during pregnancy</a> at NHS</li>\n</ul>\n", "score": 6 }, { "answer_id": 390, "body": "<p>Drinking alcohol can have some detrimental effects. While someone is pregnant, binge drinking of alcohol is very dangerous, while mild-to-moderate is more safe, but still not advised.</p>\n\n<p>\"When a pregnant woman drinks alcohol, so does her baby.\"^{<a href=\"http://www.cdc.gov/ncbddd/fasd/alcohol-use.html\" rel=\"nofollow noreferrer\">1</a>} Drinking alcohol during pregnancy raises the risk of miscarriage, stillbirth, and some physical and mental disabilites known as Fetal Alcohol Spectrum Disorders (FASDs). Children that develop FASDs are at risk for a variety of problems, such as facial defects, smaller body size, intellectual/learning disabilities, behavioral problems, and some problems in the body (vision, hearing, and organ problems). </p>\n\n<p>A meta-analysis of over 30 studies on this topic found that binge drinking causes a higher risk of FASDs in children. Moderate drinking can also be dangerous, though, and it is recommended that pregnant mothers don't drink any alcohol. \"The results of this review highlight the importance of abstaining from binge drinking during pregnancy and provide evidence that there is no known safe amount of alcohol to consume while pregnant.\"^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23905882\" rel=\"nofollow noreferrer\">2</a>}</p>\n\n<p>It is recommended that mothers abstain from drinking while pregnant, even mild drinking. Why take the risk?</p>\n\n<p>Also see <a href=\"https://health.stackexchange.com/a/373/26\">this related answer</a>.</p>\n\n<hr>\n\n<p>^{[<a href=\"http://www.cdc.gov/ncbddd/fasd/alcohol-use.html\" rel=\"nofollow noreferrer\">1</a>] <a href=\"http://www.cdc.gov/ncbddd/fasd/alcohol-use.html\" rel=\"nofollow noreferrer\">CDC - Alcohol Use in Pregnancy</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23905882\" rel=\"nofollow noreferrer\">2</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/23905882\" rel=\"nofollow noreferrer\">The association of mild, moderate, and binge prenatal alcohol exposure and child neuropsychological outcomes: a meta-analysis</a>}</p>\n\n<p><a href=\"http://www.today.com/parents/new-study-shows-no-harm-moderate-drinking-pregnancy-experts-urge-2D11849699\" rel=\"nofollow noreferrer\">^{New study shows no harm from moderate drinking in pregnancy, but experts urge caution}</a></p>\n", "score": 4 } ]

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

[ { "answer_id": 373, "body": "<p>Smoking during pregnancy is bad. <strong><em>Really bad</em></strong>. It will be damaging to the baby, and possibly even to the mother.</p>\n\n<p>Firstly, smoking during pregnancy increases the risk of miscarriages. It can also cause premature birth, which can lead to many health complications, such as low weight, feeding difficulties, and breathing problems. A mother who smokes while pregnant is also twice as likely to have abnormal bleeding during both pregnancy and delivery. This is dangerous for both the birth mother and the baby. Smoking can also cause some birth defects and puts the baby at a higher risk of Sudden Infant Death Syndrome (SIDS). The child also has a higher chance of having Cerebral Palsy (CP). When a child of a mother who smoked during pregnancy grows older, they might have lung and brain damage as they grow older.</p>\n\n<p>If a mother is exposed to secondhand smoke during pregnancy, there is still a risk of many of the complications stated above. So, whether you are a pregnant mother or the husband of one or anyone else living or spending a lot of time with a pregnant mother, don't smoke. <strong>It's not worth it.</strong></p>\n\n<p>Also see <a href=\"https://health.stackexchange.com/a/390/26\">this related answer.</a></p>\n\n<hr>\n\n<p><a href=\"http://www.cdc.gov/tobacco/campaign/tips/diseases/pregnancy.html#how-baby\" rel=\"nofollow noreferrer\">^{CDC - Smoking, Pregnancy, and Babies}</a></p>\n\n<p><a href=\"http://www.webmd.com/baby/smoking-during-pregnancy\" rel=\"nofollow noreferrer\">^{WebMD - Smoking During Pregnancy}</a></p>\n", "score": 10 }, { "answer_id": 444, "body": "<p>Smoking during pregnancy is related to many effects on health and it increases the risk in children as well. Even if the mother doesn't smoke, the risk increases significantly with higher amount of <a href=\"http://en.wikipedia.org/wiki/Passive_smoking\" rel=\"nofollow noreferrer\">passive/secondhand smoking</a>.</p>\n\n<p>These health risks include:</p>\n\n<ul>\n<li>on ongoing pregnancy:\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Premature_rupture_of_membranes#Risk_factors\" rel=\"nofollow noreferrer\">premature rupture of membranes</a>,</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Placental_abruption\" rel=\"nofollow noreferrer\">placental abruption</a> (the fetus can be put in distress, and can even die),</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Placenta_praevia\" rel=\"nofollow noreferrer\">placenta previa</a>,</li>\n<li>premature birth (~1%),</li>\n<li>implications for the umbilical cord (can result in heavy bleeding during delivery that can endanger mother and baby, although cesarean delivery can prevent most deaths),</li>\n</ul></li>\n<li>effects on the child after birth:\n\n<ul>\n<li>low birth weight,</li>\n<li>sudden infant death syndrome (SIDS)^{<a href=\"http://en.wikipedia.org/wiki/Sudden_infant_death_syndrome\" rel=\"nofollow noreferrer\">wiki</a>, <a href=\"http://www.nhs.uk/Conditions/Sudden-infant-death-syndrome/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">NHS</a>},</li>\n<li>future obesity^{<a href=\"http://web.archive.org/web/20100728080358/http://www.montrealgazette.com/health/Teen+obesity+linked+birth+tobacco+exposure+Study/2956850/story.html\" rel=\"nofollow noreferrer\">2010</a>},</li>\n<li>future smoking habits,</li>\n<li>damage to children's carotid arteries at birth and at age 5^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22201150\" rel=\"nofollow noreferrer\">2012</a>},</li>\n<li>lung infections^{<a href=\"http://en.wikipedia.org/wiki/Placenta_praevia\" rel=\"nofollow noreferrer\">1999</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22201150\" rel=\"nofollow noreferrer\">2003</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20085532\" rel=\"nofollow noreferrer\">2003</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15060193\" rel=\"nofollow noreferrer\">2004</a>}</li>\n<li>higher risks of delivering a child with congenital abnormalities, longer lengths, smaller head circumferences, and low birth weight^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20085532\" rel=\"nofollow noreferrer\">2010</a>},</li>\n<li>babies are exposed to the harmful effects of nicotine through breast milk, however benefits of breastfeeding outweigh the risks of nicotine exposure^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17766521\" rel=\"nofollow noreferrer\">2007</a>},</li>\n<li>other birth defects such as reduced birth circumference, altered brainstem development, altered lung structure, and cerebral palsy, etc.</li>\n</ul></li>\n</ul>\n\n<p>Quitting smoking at any point during pregnancy is more beneficial than continuing to smoke, especially if it's within the first 12 weeks of pregnancy.</p>\n\n<p><img src=\"https://i.stack.imgur.com/4ZL1xl.png\" alt=\"Risks from Smoking\"></p>\n\n<p>^{Image credits: <a href=\"http://commons.wikimedia.org/wiki/File:Risks_form_smoking-smoking_can_damage_every_part_of_the_body.png\" rel=\"nofollow noreferrer\">CDC</a>}</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Smoking_and_pregnancy\" rel=\"nofollow noreferrer\">Smoking and pregnancy</a> at Wikipedia</li>\n<li><a href=\"https://health.stackexchange.com/a/443/114\">Effects on children who breathe in secondhand smoke</a></li>\n<li><a href=\"http://en.wikipedia.org/wiki/Health_effects_of_tobacco\" rel=\"nofollow noreferrer\">Health effects of tobacco</a> at Wikipedia</li>\n<li><a href=\"http://www.nhs.uk/chq/Pages/2023.aspx\" rel=\"nofollow noreferrer\">Why should I stop smoking if I’m pregnant?</a> at NHS</li>\n</ul>\n", "score": 9 } ]

[ "side-effects", "obstetrics", "smoking" ]

[ { "answer_id": 434, "body": "<p>In most isolation cases, the actual order isn't going to matter, since the typical isolation area that you would be allowed to enter isn't for the patient's benefit, but other people, so that they don't catch what the patient has. In this case, it doesn't matter which order you put it on. (Especially since they are being stored in an area where anyone walking by can contaminate them).</p>\n\n<p>You will also most likely be asked to remove jackets/backpacks and other items and leave them either outside, or in the intermediate dressing area if provided.</p>\n\n<p>If the patient is immuno compromised to the point where they are worried about what you might be bringing in, then there will be a very different set of isolation precautions, and you either won't be allowed in, or they will walk you through the washing/garb donning procedures and assist you.</p>\n", "score": 6 } ]

[ "hygiene", "disinfection" ]

[ { "answer_id": 440, "body": "<p>The <a href=\"http://en.wikipedia.org/wiki/Potential_health_risks_of_sunscreen\" rel=\"nofollow noreferrer\">potential health risks of sunscreen</a> include:</p>\n\n<ul>\n<li>The absence of UVA filters combined with a longer exposure time of the sunscreen user^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/7790106\" rel=\"nofollow noreferrer\">1995</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/16086753\" rel=\"nofollow noreferrer\">2005</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17415716\" rel=\"nofollow noreferrer\">2007</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18022535\" rel=\"nofollow noreferrer\">2007</a>}.</li>\n<li>Suppression of the skin's production of melanin, a natural broad-spectrum photoprotectant^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/7790106\" rel=\"nofollow noreferrer\">1995</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15068035\" rel=\"nofollow noreferrer\">2004</a>}.</li>\n<li>Skin penetration (free radical generation) by sunscreen chemicals^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8860435\" rel=\"nofollow noreferrer\">1996</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/9310609\" rel=\"nofollow noreferrer\">1997</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17015167\" rel=\"nofollow noreferrer\">2006</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17617675\" rel=\"nofollow noreferrer\">2007</a>}.</li>\n<li><p>Cytotoxic and carcinogenic effects of nanoparticles (zinc oxide (ZnO) and titanium dioxide (TiO2) toxicity) ^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10564183\" rel=\"nofollow noreferrer\">1999</a>}.</p>\n\n<p>However <a href=\"http://web.archive.org/web/20110422105411/http://www.tga.gov.au/npmeds/sunscreen-zotd.htm\" rel=\"nofollow noreferrer\">TGA study from 2006</a> (<a href=\"http://web.archive.org/web/20110406145019/http://www.tga.gov.au///npmeds/sunscreen-zotd.pdf\" rel=\"nofollow noreferrer\">PDF</a>) concluded:</p>\n\n<blockquote>\n <p>There is evidence from isolated cell experiments that zinc oxide and titanium dioxide can induce free radical formation in the presence of light and that this may damage these cells (photo-mutagenicity with zinc oxide). However, this would only be of concern in people using sunscreens if the zinc oxide and titanium dioxide penetrated into viable skin cells. The weight of current evidence is that they remain on the surface of the skin and in the outer dead layer (stratum corneum) of the skin.</p>\n</blockquote></li>\n<li><p>DNA damage causing skin cancer (carcinogenic effects of sunscreen ingredients related to vitamin A)^{<a href=\"http://ntp.niehs.nih.gov/results/pubs/longterm/reports/longterm/tr500580/listedreports/tr568/index.html\" rel=\"nofollow noreferrer\">2012</a>}. Read below.</p></li>\n<li><p>Vitamin D deficiency^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/11920550\" rel=\"nofollow noreferrer\">2002</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495109/\" rel=\"nofollow noreferrer\">2002</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17634462\" rel=\"nofollow noreferrer\">2007</a>}.</p>\n\n<blockquote>\n <p>The strong promotion of limiting sunlight exposure because of increased risk of skin cancer has resulted in the widespread use of sunscreens. Although sunscreens are very beneficial in reducing skin damage to excessive exposure to sunlight, they also can markedly reduce the photosynthesis of vitamin D3 in the skin.</p>\n \n <p><strong>When used properly a sunscreen with a sun protection factor of 8 reduces the skin's ability to produce vitamin D3 by 97.5%</strong>^{Holick 2002}.</p>\n</blockquote></li>\n<li><p><a href=\"http://www.ewg.org/research/cdc-americans-carry-body-burden-toxic-sunscreen-chemical\" rel=\"nofollow noreferrer\">Oxybenzone (benzophenone-3) toxicity concerns</a>.</p>\n\n<blockquote>\n <p>The CDC study from 2008 reveals that 97% of Americans are contaminated with a widely-used sunscreen ingredient called oxybenzone that has been linked to allergies, hormone disruption, and cell damage.</p>\n \n <p>EWG research shows that 84% of 910 name-brand sunscreen products offer inadequate protection from the sun, or contain ingredients, like oxybenzone, with significant safety concerns. Although oxybenzone is most common in sunscreen, companies also use the chemical in at least >500 other personal care products.</p>\n \n <p>Chemical was detected in the urine of nearly every study participant. Typically, women and girls had higher levels of oxybenzone in their bodies than men and boys, likely a result of differences in use of body care products including sunscreens.</p>\n \n <p>A companion study released a day earlier revealed that mothers with high levels of oxybenzone in their bodies were more likely to give birth to underweight baby girls (Wolff 2008).</p>\n</blockquote></li>\n</ul>\n\n<h3>Retinyl palmitate (vitamin A palmitate) controversy</h3>\n\n<p>The <a href=\"http://en.wikipedia.org/wiki/National_Center_for_Toxicological_Research\" rel=\"nofollow noreferrer\">FDA's NCTR</a> and <a href=\"http://en.wikipedia.org/wiki/National_Toxicology_Program\" rel=\"nofollow noreferrer\">NTP</a> in 2009 posted on the NTP website data from FDA’s long-term photocarcinogenicity tests of retinyl palmitate on UV-exposed laboratory animals. In the studies, high doses of topical <a href=\"http://en.wikipedia.org/wiki/Retinyl_palmitate\" rel=\"nofollow noreferrer\">retinyl palmitate</a> (a form of vitamin A) were shown to accelerate cancer (skin tumors or lesions) in lab animals that grew significantly faster than mice treated with vitamin-free cream (NTP 2009).</p>\n\n<p><img src=\"https://i.stack.imgur.com/dFPlUm.png\" alt=\"Low doses of Vitamin A (retinyl palmitate) significantly speed growth of skin tumors and lesions in lab animals - chart\"></p>\n\n<p>^{Source: EWG analysis of data from FDA photocarcinogenicity study of retinyl palmitate (NTP 2009). Percent decreases in time to development of a significant tumor or lesion (for animals exposed to cream laced with retinyl palmitate) are relative to that for animals exposed to cream free of the compound.}</p>\n\n<p>Scientists have known for some time that retinyl palmitate can spur excess skin growth (hyperplasia), and that in sunlight it can form free radicals that damage DNA (NTP 2000).</p>\n\n<p>Previous data were preliminary, however in 2011 the link between <a href=\"http://en.wikipedia.org/wiki/Retinyl_palmitate\" rel=\"nofollow noreferrer\">retinyl palmitate</a> (RP), sunlight and the increased risk of cancer has been confirmed by the National Toxicology Program after a year long <a href=\"http://ntp.niehs.nih.gov/ntp/about_ntp/trpanel/2011/january/drafttr568.pdf\" rel=\"nofollow noreferrer\">study on mice</a>.</p>\n\n<p>The <a href=\"http://en.wikipedia.org/wiki/Environmental_Working_Group\" rel=\"nofollow noreferrer\">EWG</a> and and New York Senator Chuck Schumer have called attention to the fact that high doses of topical retinyl palmitate were shown to accelerate cancer in lab animals and <a href=\"http://en.wikipedia.org/wiki/Environmental_Working_Group\" rel=\"nofollow noreferrer\">EWG</a> published the following <a href=\"http://www.ewg.org/news/news-releases/2011/01/26/nih-panel-links-vitamin-sunscreen-skin-tumors\" rel=\"nofollow noreferrer\">statement</a> (which was scheduled for immediate release):</p>\n\n<blockquote>\n <p>A key independent science advisory panel has voted to confirm federal researchers' conclusion that retinyl palmitate, a form of vitamin A found in two-fifths of U.S. sunscreens, speeds the development of skin tumors and lesions when applied to the skin in the presence of sunlight.</p>\n \n <p>\"A compound that causes skin damage and tumors on sun-exposed skin has no place in sunscreens or other daytime skin products,\" said Jane Houlihan, EWG senior vice president for research.</p>\n \n <p>More than 200 sunscreens from 44 companies listed vitamin A or retinyl palmitate on their labels in 2010, according to EWG's analysis of beach and sport sunscreens with SPF ratings of 15 or higher.</p>\n \n <p>In light of those findings, EWG recommends that manufacturers of cosmetics, sunscreens and other personal care products remove retinyl palmitate from all products to be used on sun-exposed skin and that consumers avoid buying products that contain this chemical.</p>\n</blockquote>\n\n<p>Despite of that <a href=\"http://en.wikipedia.org/wiki/Potential_health_risks_of_sunscreen\" rel=\"nofollow noreferrer\">sunscreen controversy</a>, another study from 2010 by JAAD determined that \"there is no convincing evidence to support the notion that [retinyl palmitate] in sunscreens is carcinogenic.\". Therefore EWG has since refuted this analysis directly^{<a href=\"http://www.ewg.org/research/what-scientists-say-about-vitamin-sunscreen\" rel=\"nofollow noreferrer\">(2011)</a>}.</p>\n\n<p>A panel of independent scientists convened by the NTP in January 2011 unanimously <strong>confirmed the study’s conclusion that retinyl palmitate “enhanced the photocarcinogenic activity” of sunlight</strong> (NTP 2011).</p>\n\n<blockquote>\n <p>The strong scientific consensus that has formed around the NTP-FDA vitamin A study has afforded the FDA an exceptional opportunity to take a bold public health stand on a cosmetic ingredient that has proven harmful in multiple studies^{<a href=\"http://www.ewg.org/research/what-scientists-say-about-vitamin-sunscreen\" rel=\"nofollow noreferrer\">(2011)</a>}.</p>\n</blockquote>\n\n<p>Since then the FDA has set a minimum performance standard for sunscreens that use the term “broad spectrum” to denote that they provide a measure of protection from ultraviolet-A rays.</p>\n\n<p>The most recent government scientific study from August 2012 by NTP has demonstrated that <strong>retinyl palmitate speeds photo-carcinogenic effects on test animals</strong> and concluded that diisopropyl adipate increased incidence of skin tumors in mice, and the addition of either retinoic acid or retinyl palmitate both exacerbated the rate and frequency of tumors^{<a href=\"http://ntp.niehs.nih.gov/results/pubs/longterm/reports/longterm/tr500580/listedreports/tr568/index.html\" rel=\"nofollow noreferrer\">(2012)</a>,<a href=\"http://ntp.niehs.nih.gov/ntp/htdocs/lt_rpts/tr568_508.pdf\" rel=\"nofollow noreferrer\">(PDF)</a>}. The study (Photococarcinogenesis Study Of Retinoic Acid And Retinyl Palmitate) was conducted at a federal research center co-hosted by the FDA and NTP, found that mice treated with <strong>small doses of retinyl palmitate and ultraviolet light developed skin tumors faster than untreated</strong>, light-exposed mice or those treated only with a control cream. There were <strong>more numerous tumors on every animal treated with retinyl palmitate</strong>.</p>\n\n<p>And the conclusion was:</p>\n\n<blockquote>\n <p>Under the conditions of these studies, the topical treatment of SKH-1 mice with the control cream resulted in earlier onsets of in-life skin lesions and higher incidences and multiplicities of in-life skin lesions, when compared to untreated controls, in the absence and presence of SSL.</p>\n</blockquote>\n\n<p><img src=\"https://i.stack.imgur.com/RMiHv.png\" alt=\"Retinyl palmitate and light cause animals to develop skin tumors faster - chart - NTP\"></p>\n\n<p>^{This graphic presents skin tumor onset data for female and male mice exposed to the amount of UV light equivalent to 30 percent of the UV dose that causes sunburn in people. The bottom axis indicates weeks of retinyl palmitate + light treatment. (NTP 2010).}</p>\n\n<p>The sunscreen industry and its paid consultants have rejected the NTP findings.</p>\n\n<p>Whether RP in sunscreens is carcinogenic is a controversial issue for the cosmetics industry and FDA is reviewing data from several studies since July 2009. Nearly 33 years after it began considering regulation of sunscreen products, the FDA has yet to review or certify the safety of chemicals formulated into sunscreen products.</p>\n\n<p>EWG supports FDA’s proposal for further testing to determine the potential phototoxicity and/or photocarcinogenicity of diisopropyl adipate. However, more tests are likely to take some years with detailed toxicity testing with action to remove harmful ingredients from body care products. And until the government takes decisive action, consumers can have no confidence that the regulatory system for sunscreens and cosmetics is screening out suspect ingredients.</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.ewg.org/research/what-scientists-say-about-vitamin-sunscreen\" rel=\"nofollow noreferrer\">What scientists say about Vitamin A in sunscreen</a> at EWG</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Potential_health_risks_of_sunscreen\" rel=\"nofollow noreferrer\">Potential health risks of sunscreen</a> at Wikipedia</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Retinyl_palmitate\" rel=\"nofollow noreferrer\">Retinyl palmitate (vitamin A palmitate)</a> at Wikipedia</li>\n<li><a href=\"http://en.wikipedia.org/wiki/Sunscreen#Potential_risks\" rel=\"nofollow noreferrer\">Sunscreen: Potential risks</a> at Wikipedia</li>\n<li><a href=\"https://skeptics.stackexchange.com/questions/12411/does-sun-screen-cause-cancer\">Does sun screen cause cancer?</a> at Skeptics SE</li>\n<li><a href=\"https://skeptics.stackexchange.com/questions/7962/is-there-a-health-risk-from-nanoparticles-in-sunscreens\">Is there a health risk from nanoparticles in sunscreens?</a> at Skeptics SE</li>\n<li>2010: <a href=\"http://www.nydailynews.com/life-style/health/link-ingredient-sunscreen-skin-cancer-schumer-article-1.179345\" rel=\"nofollow noreferrer\">Possible link between ingredient in sunscreen and skin cancer: Schumer</a> at NY Daily</li>\n<li>2010 article: <a href=\"https://www.truthinaging.com/review/retinyl-palmitate-sunscreen-and-skin-safety\" rel=\"nofollow noreferrer\">Retinyl palmitate sunscreen and skin safety</a></li>\n<li>2011 article: <a href=\"https://www.truthinaging.com/review/new-study-links-retinyl-palmitate-to-cancer\" rel=\"nofollow noreferrer\">New study links retinyl palmitate to cancer</a></li>\n</ul>\n", "score": 14 }, { "answer_id": 488, "body": "<h1>Wearing sunscreen while out in the sun cuts your risk of skin cancer.</h1>\n<p>As others have pointed out, there are some potential risks associated with wearing sun screen. However, if you are out in the sun, these risks are <em>far</em> outweighed by the risk of UV exposure.</p>\n<p><a href=\"https://skeptics.stackexchange.com/a/14269\">This Skeptics.SE answer</a> has a very comprehensive overview of the facts, in particular citing a recent <a href=\"http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0781.2011.00557.x/full\" rel=\"noreferrer\">critical review</a> that assessed <em>all</em> studies related to sun screen to date. This was the conclusion:</p>\n<blockquote>\n<p>Given sunscreens prevent Squamous cell carcinoma (SCC) and sunburn (although this study claims it is inconclusive in preventing melanomas and and basal cell carcinoma (BCC)), their use seems justified despite the fears.</p>\n</blockquote>\n", "score": 9 }, { "answer_id": 438, "body": "<p>Your question sounds like it generalizes about all sunscreen products. But not all sunscreen products are created equal.</p>\n\n<p>I understand your concern because according to <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25671455\">this report from the National Institute of Health</a></p>\n\n<blockquote>\n <p>Recent reports about sunscreen safety have received widespread media\n attention</p>\n</blockquote>\n\n<p>Media attention will lead to opinion based questions. So here's my recollection of opinions + facts: </p>\n\n<p>Remember that anything that damages your DNA has the potential to cause cancer, excess and misuse of sunscreen can cause cancer. </p>\n\n<p>After reading a bit from experts on the topic my non-expert recommendation would be:</p>\n\n<ol>\n<li>Use it in moderation. Use sunscreen only when you are going to be\nexposed directly to the sun for more than a few minutes on peak sun\nhours (10 am to 2 pm). Or if you are going to be exposed for several\nhours regardless of peak hours.</li>\n<li>Use it in the form of ointment/gel/liquid/unguent. Don't use sprays\nbecause you should never be breathing that stuff. Use it in the skin\nonly. Don't use it in sensible areas that could absorb it faster,\nlike areas where there are mucous tissue (eyes, mouth, genitals,\netc). You should never be eating that stuff.</li>\n<li>Use inorganic sunscreen because organic has a higher potential to\ncause allergies and/or disrupt your hormones.</li>\n</ol>\n\n<p>Disclaimer: My informed opinion is no substitute for professional advice. Consult your physician or GP.</p>\n\n<p><strong>References</strong> obtained from pubmed, and there's some expert's opinion you can read in the following article (it is <strong><em>not licensed under creative commons</em></strong> so that's why I paraphrased it), the article is also <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25671455\">directly referenced by the National Institute of Health</a> so I'd say is somewhat reliable:</p>\n\n<p>Direct link:<br>\n<a href=\"http://www.cutis.com/?id=27148&amp;tx_ttnews[tt_news]=372913&amp;cHash=2f78ef616315bff3cc04ef761a0611bd\">http://www.cutis.com/?id=27148&amp;tx_ttnews[tt_news]=372913&amp;cHash=2f78ef616315bff3cc04ef761a0611bd</a></p>\n\n<p>If the direct link doesn't work enter: </p>\n\n<ul>\n<li><a href=\"http://www.cutis.com/\">http://www.cutis.com/</a></li>\n<li>And search for \"sunscreens-causing-cancer-the-facts\"</li>\n</ul>\n", "score": 6 } ]

[ "dermatology", "cancer" ]

[ { "answer_id": 445, "body": "<p>The CDC lists two: <a href=\"http://www.cdc.gov/condomeffectiveness/brief.html\" rel=\"noreferrer\">complete abstinence, and being in a long-term mutually monogamous relationship with an uninfected partner</a>.</p>\n\n<p>Sexual intercourse naturally introduces microtears (small tears in the the epithelial layer) through which diseases can transfer between partners. One might think that additional lubrication would help with this, but <a href=\"http://www.catie.ca/en/pif/spring-2011/research-update-are-lubes-safe-anal-sex\" rel=\"noreferrer\">the jury is most definitely out on that.</a></p>\n\n<p>I think it's pretty safe to say that if there was another clinically verified way of preventing STDs, the CDC would have put it on <a href=\"http://www.cdc.gov/std/prevention/default.htm\" rel=\"noreferrer\">this list</a>. (For example, they note that there are specific things you can be vaccinated against, namely hepatitis B and HPV.) It strains credulity to think that there is a mechanism available that the CDC just forgot to mention there.</p>\n\n<p>Having said all of that, I'll just mention the fact that there are a variety of types of condoms. If you are in a situation where you need to use them (e.g. non abstinent and not in a long term monogamous relationship), you might be able to find a brand or type that works better for you.</p>\n\n<p>EDIT: A comment has pointed out that a cervical barrier method can reduce the risk of transmission of certain types of STIs. Since that does not show up on the CDC list I mentioned, I feel that it's worth bringing up. By no means is that a \"safe substitute\" for a condom (and I don't think anyone is implying that it is). However, as a risk <em>reducer</em>, it should be added to the list.</p>\n", "score": 9 } ]

[ "sti", "contraception", "sex" ]

[ { "answer_id": 10433, "body": "<p>You don't need at all to use any mouthwash. A healthy mouth is <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26811460\" rel=\"nofollow noreferrer\">full of bacteria</a>, almost all of them beneficial for our health, and </p>\n\n<ol>\n<li>There is no evidence so far of any long term preventive effect of any kind of mouthwash, only trials with <a href=\"http://onlinelibrary.wiley.com/doi/10.1111/odi.12187/pdf\" rel=\"nofollow noreferrer\">transient effects (&lt; one year)</a> or <a href=\"http://jada.ada.org/article/S0002-8177(15)00336-0/abstract\" rel=\"nofollow noreferrer\">6 months</a> in surrogate clinical endpoints as number of bacteria and gingivitis. The only one with some evidence are <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/27472005\" rel=\"nofollow noreferrer\">fluoridated-based mouthwashes</a>, but you get the same effect if you <a href=\"http://www.nature.com/bdj/journal/v212/n7/full/sj.bdj.2012.260.html\" rel=\"nofollow noreferrer\">don't spit after brushing with fluoridated toothpaste</a>; </li>\n<li>If you still decide to use, the only risk is the <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22957711\" rel=\"nofollow noreferrer\">staining and metallic taste</a> from chlorhexidine-based mouthwashes. There is no evidence so far of risk of oral cancer associated with the use of <a href=\"https://health.stackexchange.com/questions/475/how-frequently-should-non-alcoholic-mouthwashes-be-used\">essential oil–containing mouthrinses</a>.</li>\n</ol>\n\n<p>Instead, you may invest your money in <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22652212\" rel=\"nofollow noreferrer\">cheese</a> for your oral health. </p>\n\n<p>Lastly, if you are interested in joining a study to increase our limited knowledge about mouthrinses for oral health, there are some trials <a href=\"https://clinicaltrials.gov/ct2/show/NCT02546804\" rel=\"nofollow noreferrer\">recruiting</a>.</p>\n\n<p>So, in brief: daily use of fluoridated toothpaste without spitting after using it is enough if you already are eating enough <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/19467151\" rel=\"nofollow noreferrer\">fruits and vegetables</a> and limiting the consumption of sugar.</p>\n", "score": 2 } ]

[ "dentistry", "risks", "mouthwash", "frequency", "proper-use" ]

[ { "answer_id": 528, "body": "<p>Not all contacts are made the same even in the same pack. I have no idea what the acceptable level of failure is for contact manufacturers though. </p>\n\n<p>Let's assume that you abide by all the usage instructions; that is, if they are monthly, weekly, or daily, you change them at that correct interval. Also, note that some contact lenses will have a longer life span with certain contact lens solutions. Off the top of my head, Air Optix is one of these brands. With this brand, you should be using Pure Moist I believe. Just following the boxes cleaning regiment will not suffice if you are using the wrong solution with the lenses. </p>\n\n<p>Now, let's suppose you are doing everything correctly. Unfortunately, some lenses will not be up to par (such is engineering and in life not everything is perfect). Therefore, this set of lenses will become less breathable in a shorter amount of time. If you are the unlucky soul who perpetually gets the dud box, there can be negative side effects. One side effect is from ischemia which was mentioned in the comments. When the eye is starved of oxygen, blood vessels will begin to grow on the eye in order to get oxygen rich blood to the tissue and over time will cause Corneal Neovascularization.</p>\n\n<p>The scenario I described is a long shot but it cold theoretically happen although it is very unlikely.</p>\n\n<p>Other side effects could be that you get some kind of dirt or grim in your eye that gets under the contact lenses. This foreign body could end up scratching the cornea.</p>\n\n<p>However, if you are diligent in following your eye care instructions, use the correct contact lenses solutions, and use common sense, more than likely, you will not have any problems from wearing contact lenses.</p>\n\n<ol>\n<li><a href=\"http://optometrist.com.au/corneal_neovascularization/\" rel=\"noreferrer\">Contact Lenses cause Corneal Neovascularization</a></li>\n<li><a href=\"http://www.webmd.com/eye-health/corneal-abrasions\" rel=\"noreferrer\">Corneal Abrasion</a></li>\n</ol>\n", "score": 5 } ]

[ "side-effects", "eye", "ophthalmology", "lenses" ]

[ { "answer_id": 3087, "body": "<p>There are a few other active ingredients you could try for dandruff (seborrheic dermatitis), if that's what's causing your problem. Keep in mind that it <strong>might</strong> actually be a different problem, such as eczema or scalp psoriasis. From a quick internet search, the active ingredient in \"Dettol Anti-bacterial Soap\" is cholroxylenol, is that correct? If so, here are some others you might want to try (i.e. read the product label and look for one of the active ingredients below).</p>\n\n<p>Note, these are \"over-the-counter\" options only (avaliable without a prescription). A doctor can prescribe other treatments that might not be listed below, or in a stronger formulation than what's available over-the-counter.</p>\n\n<ol>\n<li><p><strong>pyrithione zinc</strong>: usually found in dandruff shampoos like Head &amp; Shoulders; also available in a soap/cleanser form.</p></li>\n<li><p><strong>selenium sulfide</strong>: usually found in dandruff shampoos like Selsun Blue; it's also available in topical forms, but that may require a prescription.</p></li>\n<li><p><strong>ketoconazole</strong>: this is an antifungal ingredient found in anti-dandruff shampoos such as Nizoral shampoo (and generic store-brand equivalents) containing 2% ketoconazole. Stronger formulations are available by prescription. </p></li>\n<li><p><strong>coal tar</strong>: usually found in dandruff shampoos like Neutrogena T-Gel or Denorex; also available in soap form; >> NOTE: this stuff has a strong \"unique\" smell... make sure you can tolerate the smell before using it. :)</p></li>\n<li><p><strong>salicylic acid</strong>: usually in found in certain facial cleansers (often with the term \"oil-free acne cleanser\"); it's also found in some dandruff shampoos for \"flaky scalp\" (like Neutrogena T-Sal), so it's not necessarily just for acne.</p></li>\n</ol>\n\n<p>You might also consider taking a break from using the Pantene products in contact with your face, and switch to something &lt;&lt;<strong>without</strong>>> a lot of moisturizers, and not containing silicone (that's usually what the \"shine\" ingredient is). </p>\n\n<p>This might sound silly, but you could also try \"baby shampoo\" (fragrance/moisturizer free) for a while, particularly if you're alternating with the medicated shampoos as directed on their label. </p>\n\n<p>One \"last resort\" option in this case might be to shave your beard (omg!), and see if that helps. You may be reluctant to try that, but remember you can always grow it back later. Howecer, if you do shave the beard and the condition resolves itself, it may be time to rethink the beard. :(</p>\n\n<p>If none of those work, it's probably best to see a doctor about it. They would be able to prescribe something more specific. They may end up prescribing something with one of those ingredients above, but in a higher strength. Alternatively, they might prescribe a topical steroid anti-inflammatory for you to use for a period of time, in case it's <strong>not</strong> dandruff and is actually something like eczema.</p>\n\n<p>Hope that helps!!</p>\n\n<p>Here's a helpful reference (from the Mayo Clinic website) on seborrheic dermatitis/dandruff. It also includes the topic of facial (beard) dandruff:<br>\n<a href=\"http://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/basics/definition/con-20031872\">http://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/basics/definition/con-20031872</a></p>\n\n<p>More details on \"over-the-counter\" treatments listed above are included in the section called \"home remedies\":<br>\n<a href=\"http://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/basics/lifestyle-home-remedies/con-20031872\">http://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/basics/lifestyle-home-remedies/con-20031872</a></p>\n", "score": 7 } ]

[ "hygiene", "hair" ]

[ { "answer_id": 794, "body": "<p>The estimated daily requirement needed to maintain body stores of B12 varies, an estimate being from 2µg to 5µg, more if stores have been depleted in any way. It is estimated that the average person stores about 1 mg (1000 µg) of B12 in their liver, and other smaller amounts elsewhere. The recommended daily allowance assumes a 50% absorption rate of ingested B12.</p>\n\n<p>This is a good question to discuss the limits of medical science. How is the requirement for B12 determined?</p>\n\n<p><em>Longitudinal studies</em> are those that follow people over many years (even decades.) Humans are not subjected to longitudinal studies involving, say, B12 because:</p>\n\n<ul>\n<li>it would be <strong>unethical</strong> to withhold from some subjects a vitamin necessary for health and well-being while providing it to others just to get an exact number (for the sake of scientific curiosity)</li>\n<li>there are ethical issues in involvement of the young (parental consent should not extend to potential harm)</li>\n<li>if participants are paid volunteers, the study introduces a bias in recruitment (more poor people?) This affects the ability to generalize to the total population, because there may be inherent risks of confounding variables</li>\n<li>the cost of such a study would be prohibitive (who will collect the data, control the diets, pay for the food, and determine outcomes, etc.)</li>\n<li>it is impossible to regulate someone's diet for years or decades (one person sneaking out to eat a dozen oysters could ruin the experiment) </li>\n<li>it would be unethical to control someone's diet for decades (what if someone who signed up for the study later became a vegan on moral grounds? They would either be forced to eat meat or drop out of the study) </li>\n<li>longitudinal studies suffer from cumulative attrition - people die of unrelated causes, move to another area, decide to drop out for other reasons, etc.</li>\n<li>(many more problems)</li>\n</ul>\n\n<p>Therefore different study models must be used, which give us less accurate information, such as retrospective studies, animal studies, studies of treatment of pernicious anemia (a result of B12 deficiency), pregnant and lactating vegans, people who have undergone certain bypass procedures, etc. By studying those patients, it can be determined how much B12 is necessary to the first signs of B12 deficiency away (usually apparent in blood).</p>\n\n<p>B12 is a particularly difficult vitamin to pin down because of its\ncomplexity, the fact that it is synthesized by intestinal flora, and the various steps involved in its absorption which might be influenced by age and other factors.</p>\n\n<p>Again, the estimated daily requirement of B12 varies from ~ 2µg to 5µg.</p>\n\n<p>Since there are no known adverse effects of excess B12 intake, it's not unreasonable to take more than the minimum if warranted. However, a recommendation of 500 - 1000 µg/day seems quite unnecessary.</p>\n\n<p>_{<a href=\"http://books.google.com/books?hl=en&amp;lr=&amp;id=p7XwAwAAQBAJ&amp;oi=fnd&amp;pg=PA459&amp;dq=minimum+daily+requirement+of+B12+in+humans&amp;ots=jlX0km_i0w&amp;sig=brLcOBBtgdOWs1mpqUMDDt4Mq20#v=onepage&amp;q&amp;f=false\">Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics (Carl A. Burtis, David E. Bruns, 2014, p 474</a>}</p>\n", "score": 12 }, { "answer_id": 4898, "body": "<p>Let me address this point mentioned in the question: \"My apothecary person told me 500-1000 µg per day are needed to even start absorbing meaningful quantities by ingestion.\"</p>\n\n<p>This addresses a problem with the way we absorb vitamin B12. As <a href=\"https://en.wikipedia.org/wiki/Vitamin_B12#Enzyme_function\" rel=\"nofollow noreferrer\">explained here</a>, when vitamin B12 is ingested, certain so-called transport proteins are needed to move it to the bloodstream. Now, at any given time you only have an amount of enzymes capable of transporting about 1.5 micrograms. When you take 5 to 50 micrograms, you saturate the capacity of the transport proteins, and you'll get close to the maximum of 1.5 micrograms of vitamin B12 into your body.</p>\n\n<p>However, a small fraction of the vitamin B12, about 1% will pass through the stomach wall without the help of transport proteins. This means that you can evade the 1.5 micrograms per meal absorption limit by taking huge dosages of the order of many hundreds of micrograms. This is useful for people who are deficient, they'll typically have a problem causing vitamin B12 to not be absorbed using the transport proteins. Even if there is no problem here (e.g. in case of malnutrition) with only 1.5 micrograms per day, a deficiency cannot be corrected in a timely manner. High dose supplements or vitamin B12 injections must then be used. </p>\n\n<p>The 200 micrograms prescribed by your doctor thus amounts to an effective dose of 1.5 micrograms plus 1% of 200 micrograms = 3.5 micrograms of vitamin B12 which is within the range of the RDA.</p>\n", "score": 2 } ]

[ "obstetrics", "b-12-supplements", "absorption-absorb", "apothecary", "prenatal-vitamins" ]

[ { "answer_id": 923, "body": "<p>Yes, I understand you. I have been fighting a depression myself for the past months, although it must have gone on longer than that, undiagnosed. I know how it feels, and understand how you just want it gone away. </p>\n\n<p>The direct answer to your question is: Selective memory loss is impossible. There is no way to forget that past year. But there is a way to get over the depression without forgetting. </p>\n\n<p>The insidious thing about depression is that it makes everything seem like an insurmountable problem, and makes you feel incapable of solving it. So of course, you want the problems gone away. But the way forward is not to change the events which happened, or erase your memory of them. It is to learn that they are not really as bad as they feel, even when your depressed mind is convinced that they are terrible. </p>\n\n<p>I know it might seem impossible to you to do so - after all, you are feeling in your bones that they are bad things. But clinical practice, and my own experience, shows that it is very possible. \"Seeing the world with different eyes\" is a skill which can be learned, just like you can learn to knit socks or play the piano. And there are many things you can do to learn it - reading books, talking to a specialist (therapist), observing and imitating those who have it, talking with others who are going through the same process, practicing your new skill, and having support from non-affected friends and family members who cheer your success without putting you into a pressure trap. </p>\n\n<p>One of the tricky things about depression is that it saps our motivation to do anything, even the things which will heal us. It is very logical: why do something that is hopeless? The important thing here is to recognize that this hopelessness is not real, it is an illusion created by the illness. It's hard to get over it, because it feels absolutely real, but it is possible. If your ability to motivate yourself is so far down you cannot start with something as hard as cognitive therapy, you could start a medication course (st john's worth for milder cases, if you don't take any other medications, or go straight for synthetic antidepressants), which will give you the initial \"spark\" which will give you the energy to pack your problems at the root. </p>\n\n<p>You will need a long time until you start feeling normal again, but believe me, it does work, even it is a hard, two-steps-forward-one-backward road. And even when the goal is still far away, the gradual progress is better than staying in place. </p>\n\n<p>The result of it will be that you won't have forgotten what happened to you that last year. But the memories will just be memories, which will not make you feel like an anxious, hopeless failure, the way they do now. Right now, you experience them like a barrier blocking your way forwards in life, and want them gone. When you learn to manage the depression, they will be more like a chalk line on your way - you can step over it without it holding you back in any way. </p>\n\n<hr>\n\n<p>Many of the resources you need have to be found locally, but I can suggest a few books. I have read tons of them in my own healing process, but these are the ones I found most helpful. </p>\n\n<ul>\n<li><a href=\"http://rads.stackoverflow.com/amzn/click/1593851286\">\"The mindful way through depression\" by Mark Williams</a>. It is a straight depression self-help book, and the program outlined there is worth it. But even if you can't bring yourself to go through the program, just reading it will bring you valuable insights. </li>\n<li><a href=\"http://rads.stackoverflow.com/amzn/click/0804136726\">\"Performing under pressure\" by Hendrie Weisinger and J. P. Pawliw-Fry</a>. When you are depressed, your problems seem much more overwhelming, while the energy you have to deal with them goes down. Learning strategies to make the best out of your limited energy is very helpful, and can bring you into an important positive feedback loop - the more problems you solve, the less hopeless you feel. </li>\n<li><a href=\"http://rads.stackoverflow.com/amzn/click/159285849X\">\"The gifts of imperfection\" by Brene Brown</a>. Depression makes us feel flawed, like we have failed at being proper humans. There are schools of thought which support such conclusions, and this book exposes the errors of these ways of thinking. </li>\n<li><a href=\"http://rads.stackoverflow.com/amzn/click/031254152X\">\"On being certain\" by Robert Burton</a>. We grow up believing in, well, our beliefs. But a successful cognitive change requires us to recognize that some of our beliefs are wrong, no matter how right they feel. This book is probably not for everybody, and it does not address the problem of depression directly. But once you realize that there are cognitive illusions, just like there are optical illusions, it becomes much easier to understand how a cognitive behavioral therapy or a mindfulness training works, and to not dismiss it as mumbo jumbo from the start. </li>\n</ul>\n\n<hr>\n\n<p>Good luck with your journey. And don't forget: you don't have to be special, or a super hero, to get over your own depression. All you need is the knowledge how to do it (I listed the sources above) and the tenacity to not give up when it feels hopeless. </p>\n", "score": 14 } ]

[ "depression", "cognitive-science" ]

[ { "answer_id": 928, "body": "<p>There are certain types of malocclusion that are have been shown to adversely affect quality of oral health and quality of life, but these are far, far fewer than the number of people sporting braces, adult or adolescent. The need for braces in the average teen, therefore, is no greater than the average adult. If you think of braces for teens as a necessity, it is no less a necessity for adults, that is, appearance is probably the only significant result for both average teens and adults.</p>\n\n<p>However, increased longevity has led to the need to keep healthy teeth for longer periods. Teeth continue to shift throughout life. Missing teeth (today's older adults are more likely to have had dental extractions than younger adults) allow teeth to shift, resulting in malocclusion. Malocclusion in turn can result in frequent inadvertent oral mucosal injuries. This can be corrected with braces.</p>\n\n<p>Missing teeth also mean less occlusive surfaces (chewing surface area). Believe it or not, this poses a choking hazard, as well as decreases a person's ability to enjoy certain foods. Braces or other orthodontic devices may be needed to shift teeth into proper position for bridges to restore occlusive surfaces. Since people are living longer, it makes sense to invest in procedures that will help you to continue to eat well.</p>\n\n<p>Recent reviews of dental literature, however, are showing that the oral health benefits of orthodontic intervention in adults are more limited. Malocclusion seems not to have a role in susceptibility to dental caries (as was previously believed), periodontal disease, and temporomandibular joint disorder. Therefor the oral health benefits of orthodontic intervention are more limited than previously believed.</p>\n\n<p>Finally, there is some evidence that adult orthodontics can result in harm in the form of root shortening, which can lead to loose teeth.</p>\n\n<p>_{<a href=\"http://www.sciencedirect.com/science/article/pii/S0003996901000231\">Determinants of masticatory performance in dentate adults</a>}<br>\n_{<a href=\"http://www.sciencedirect.com/science/article/pii/S0889540612005781\">Dental crowding as a caries risk factor: A systematic review</a>}<br>\n_{<a href=\"http://informahealthcare.com/doi/abs/10.3109/00016358909007704\">Causal relation between malocclusion and caries</a>} </p>\n", "score": 11 } ]

[ "dentistry", "cosmetics", "dental-braces", "teeth-alignment" ]

[ { "answer_id": 1102, "body": "<p>No, this does not alter them, or make them less effective. There are problems with a scant amount of medicine crumbling, as you've noticed.</p>\n\n<p>The only real concern I'd have for anyone doing this is regarding the authorities: for example, while traveling out of the country, it's good to keep your medicines in their original prescription bottles because it supports you're assertion that the medicines are all <em>prescribed</em> to <em>you</em>. In my entire life, I had only one border agent question my medications. So even there, it's rare.</p>\n\n<p>As long as you can tell which pill is which, this is perfectly safe.</p>\n\n<p>One way to decrease crumbling of a pill is to put a piece of cotton in your container, so that when you close it, the pills don't rattle around in your purse. That's the reason many medications come with a cotton ball stuffed into the bottle.</p>\n", "score": 7 }, { "answer_id": 4260, "body": "<p>The integrity of the pills themselves should be fine with a few exceptions. I won't ask you what you take, but note that there are situations where this powder can cause problems. Though, it is rather unlikely.<br>\nThe only thing I will add to this, as a pharmacist, is keeping all your pills in a single container makes identifying them difficult/time consuming for a third party. If you were in a situation where you or a loved/trusted one was unable to list your medications, having them all together makes this situation much more difficult and potentially harmful to you. <br>\nBy law, all prescribed medication marketed and sold within the US are required to have a stamp on them for identification purposes (see: <a href=\"http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=206.7\" rel=\"noreferrer\">FDA's Code of Federal Regulations</a>). If there are many different medications in a single container it is easier for a single pill to be missed in the sorting phase (as many pills are small, white, and round making them look incredibly similar). This could hurt you in the short and long run. Better to get a cheap pill box to separate them at least by what you take each day to cut down on some of this.</p>\n", "score": 5 } ]

[ "medications" ]

[ { "answer_id": 2000, "body": "<p>It is not possible. </p>\n\n<p>The regulation of human body temperature (thermoregulation) is very subtle. Wikipedia article about thermoregulation contains a very nice graph about that mechanism.\n<a href=\"https://i.stack.imgur.com/OgG4H.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/OgG4H.png\" alt=\"enter image description here\"></a></p>\n\n<p>The labels are not described in the text in detail and the reference in the caption does not include this picture. Picture is a work by one JW Dietrich and I also searched PubMed for this guy, but he has no works on this topic. </p>\n\n<p>Another more pragmatic picture is here.</p>\n\n<p><a href=\"https://i.stack.imgur.com/bGim4.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/bGim4.jpg\" alt=\"enter image description here\"></a></p>\n\n<p>Fever or increased body temperature is almost solely caused by to the production <a href=\"https://en.wikipedia.org/wiki/Fever#Pathophysiology\" rel=\"noreferrer\">prostaglandin E2 (PGE2)</a>. PGE2 acts on the hypothalamus or the thermoregulator of the body and as a result body temperature increases (<a href=\"https://en.wikipedia.org/wiki/Fever#Pathophysiology\" rel=\"noreferrer\">1</a>). PGE2 production is controlled by the immune system. Fever is meant to have a good cause since fever is supposed to help killing the bacteria or viruses causing any illness.</p>\n\n<p>Antipyretics are drugs which interact with PGE2. Basically they suppress the formation of PGE2. In that way they \"treat\" the fever.</p>\n\n<p>As can be seen from the control circuit describing the thermoregulation PGEs has nothing to with this process. Due to this, blocking non existing PGE2 production during normal body temperature has no effect whatsoever which would cause the body temperature to drop. Even it would happen with some mysterious cause, the body rapidly balance the situation as seen above in the figures.</p>\n", "score": 8 }, { "answer_id": 16616, "body": "<p>Kudos for finding that study on mice! I also googled a bit for references..</p>\n<p>From &quot;Physiology Secrets&quot; (<a href=\"https://books.google.ru/books?id=a1RchCrwKWsC&amp;lpg=PA315&amp;ots=R_v5D-uOUE&amp;dq=aspirin%20decreases%20normal%20body%20temperature&amp;hl=ru&amp;pg=PA315#v=onepage&amp;q=aspirin%20decreases%20normal%20body%20temperature&amp;f=false\" rel=\"noreferrer\">page 315</a>) by Hershel Raff, published in 2003:</p>\n<blockquote>\n<p><a href=\"https://i.stack.imgur.com/4EqsB.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/4EqsB.png\" alt=\"enter image description here\" /></a></p>\n</blockquote>\n<p>Furthermore, in one other source the author says that aspirin can even induce hyperthermia (elevated body temperature) (&quot;Applied Pharmacology for the Dental Hygienist&quot; by Elena Bablenis Haveles, 2015, <a href=\"https://books.google.ru/books?id=gfYoDgAAQBAJ&amp;lpg=PA606&amp;ots=hvghGZG_-f&amp;dq=aspirin%20decreases%20normal%20body%20temperature&amp;hl=ru&amp;pg=PA606#v=onepage&amp;q&amp;f=false\" rel=\"noreferrer\">page 606</a>):</p>\n<blockquote>\n<p><a href=\"https://i.stack.imgur.com/0VFyq.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/0VFyq.png\" alt=\"enter image description here\" /></a></p>\n</blockquote>\n<p>A research article, detailing research performed on healthy subjects:</p>\n<blockquote>\n<p><a href=\"https://www.wemjournal.org/article/S1080-6032(11)00157-8/pdf\" rel=\"noreferrer\">The Effects of High- and Low-Dose Aspirin on Thermoregulation During and After Acute Cold Exposure</a> (Murray et al., 2011, Wilderness and Environmental Medicine)</p>\n<p>Conclusions. — These data demonstrate that aspirin had no significant effect on the thermal and metabolic responses during acute cold exposure and rewarming.</p>\n</blockquote>\n<p>Figure from the article:</p>\n<blockquote>\n<p><a href=\"https://i.stack.imgur.com/7zfgU.png\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/7zfgU.png\" alt=\"enter image description here\" /></a></p>\n</blockquote>\n<p>(High-dose aspirin: 650 mg/day for one week; low-dose aspirin: 81 mg/day for one week)</p>\n", "score": 5 } ]

[ "medications", "body-temperature", "anti-inflammatory" ]

[ { "answer_id": 1743, "body": "<p>Evidence for the benefits of yoga is vast and easily accessible online. It is great to see question like this which focus on the comparison of yoga to other exercises. </p>\n\n<p>There is quite limited amount of studies which investigate the benefits of yoga over another type of exercise. </p>\n\n<p>When kids were examined yoga did not show benefits over traditional exercises <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24199742\" rel=\"nofollow\">(1)</a>. In my opinion this is due to the fact that children aged between 8 and 13 years are not <em>sensible</em> to the great effects of yoga. Hardly any kids that age experience stress or mental problems which could be relieved by mental exercises.</p>\n\n<p>In another study slightly older participants were examined <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25024234\" rel=\"nofollow\">(2)</a>. When compared to stretching the patients having participated to a yoga intervention showed greater effects in executive functions and also in flexibility.</p>\n\n<p>In another study setting women with breast cancer were investigated <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/24590636\" rel=\"nofollow\">(3)</a>. Again compared to stretching, yoga was superior with regard to quality of life and fitness.</p>\n\n<p>As so, I think there is good evidence favouring yoga at least over stretching. Unfortunately there is scarcely studies investigating the benefits of yoga over, say jogging or gym exercises.</p>\n", "score": 4 } ]

[ "exercise", "benefits", "yoga" ]

[ { "answer_id": 1436, "body": "<p>I think there's a link, but no one can say that this is the cause of myopia</p>\n\n<p>According to <a href=\"http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/myopia?sso=y\" rel=\"noreferrer\">American Optometric Association</a> : </p>\n\n<ul>\n<li>The exact cause of nearsightedness is unknown, but two factors may be primarily responsible for its development: Heredity and Visual Stress</li>\n</ul>\n\n<blockquote>\n <p>Even though the tendency to develop nearsightedness may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop nearsightedness.</p>\n</blockquote>\n\n<p>Also :</p>\n\n<ul>\n<li><p>Some people may experience blurred distance vision only at night. This “night myopia” may be due to the low level of light making it difficult for the eyes to focus properly or the increased pupil size during dark conditions, allowing more peripheral, unfocused light rays to enter the eye.</p></li>\n<li><p>People who do an excessive amount of near vision work may experience a false or “pseudo” myopia. Their blurred distance vision is caused by over use of the eyes’ focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. The symptoms are usually temporary and clear distance vision may return after resting the eyes. However, over time constant visual stress may lead to a permanent reduction in distance vision.</p></li>\n<li><p>Symptoms of nearsightedness may also be a sign of variations in blood sugar levels in persons with diabetes or an early indication of a developing cataract.</p></li>\n</ul>\n\n<p><a href=\"http://www.nhs.uk/Conditions/Short-sightedness/Pages/Causes.aspx\" rel=\"noreferrer\">NSH</a> give us more input about your specifics questions :</p>\n\n<blockquote>\n <p>One study found that children who read for 30 minutes or more each day were one-and-a-half times more likely to develop myopia than children who didn't read for this period of time.\n Research has also shown that children who spend time doing outdoor activities, such as playing sports, are less likely to become short-sighted and existing short-sightedness may progress less quickly.\n It is thought that this protective effect could be associated with the higher light levels outside than inside, and the fact that you are not constantly focusing on near objects.\n An \"everything in moderation\" approach is recommended. Although children should be encouraged to read, they should also spend some time away from reading and computer games each day doing outdoor activities.</p>\n</blockquote>\n\n<p>That being said, since most of studies link this cause of effect on developing eye's, i don't think this could make your myopia worse after you is past 21 years old and your eye's is completely grown.</p>\n", "score": 8 }, { "answer_id": 14542, "body": "<p>I think the best known environmental risk factor (to date) for myopia is lack of intense/outdoor light exposure. The pathway for this is reasonably well understood, namely: lack of intense light exposure leads to lowered dopamine, which is necessary to prevent eye growth, which in turn leads to myopia.</p>\n\n<p>This based on relatively recent evidence, but it is of reasonable quality:</p>\n\n<ul>\n<li><p>three successful interventional studies (clinical trials) have been conducted <a href=\"https://doi.org/10.1016/j.ophtha.2012.11.009\" rel=\"nofollow noreferrer\">first in Taiwan</a>, <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4495846/\" rel=\"nofollow noreferrer\">then in China</a> and <a href=\"https://doi.org/10.1001/jama.2015.10803\" rel=\"nofollow noreferrer\">again in China</a> (<a href=\"https://en.wikipedia.org/wiki/Randomized_controlled_trial\" rel=\"nofollow noreferrer\">RCT</a> this time); there's <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5599950/\" rel=\"nofollow noreferrer\">a meta-analysis</a> of these which gives the <a href=\"https://en.wikipedia.org/wiki/Forest_plot\" rel=\"nofollow noreferrer\">forrest plot</a> below:\n<a href=\"https://i.stack.imgur.com/k78Hp.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/k78Hp.png\" alt=\"enter image description here\"></a></p></li>\n<li><p>three older <a href=\"https://en.wikipedia.org/wiki/Cohort_study\" rel=\"nofollow noreferrer\">cohort studies</a> included in the aforementioned meta-analysis also found an association between light exposure and myopia, and so did a bunch of <a href=\"https://en.wikipedia.org/wiki/Cross-sectional_study\" rel=\"nofollow noreferrer\">cross-sectional studies</a>, albeit weakly. The meta-analysis conclusion was \"Increased time outdoors is effective in preventing the onset of myopia as well as in slowing the myopic shift in refractive error. But paradoxically, outdoor time was not effective in slowing progression in eyes that were already myopic.\" </p></li>\n<li><p>a prospective <a href=\"https://en.wikipedia.org/wiki/Longitudinal_study\" rel=\"nofollow noreferrer\">longitudinal study</a> (i.e. repeated measures) <a href=\"https://doi.org/10.1167/iovs.14-15978\" rel=\"nofollow noreferrer\">in Australia</a> using for the first time a wrist-worn light sensor to measure actual light exposure found \"modest but statistically significant relationship between objectively measured daily light exposure and axial eye growth (adjusting for potential confounders) indicating that greater average daily light exposure results in less axial growth of the eye in childhood.\" And concluded that \"These findings support the role of light exposure in the documented association between time spent outdoors and childhood myopia.\" Its findings are consistent with other older studies e.g. <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23380471\" rel=\"nofollow noreferrer\">one in Denmark</a> that used day length as an approximation for light exposure. </p></li>\n<li><p>some animal models <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/23434455\" rel=\"nofollow noreferrer\">support</a> the pathway: in particular a dopamine blocker <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/20445123\" rel=\"nofollow noreferrer\">given to chicken</a> abolished the preventative effect of sunlight on myopia development. Some questions remain in this area though, in particular knock-out mice models insofar did not reproduce the effect.</p></li>\n<li><p>High-quality science news sources highlighted the new discoveries: in particular, <em>Nature</em> had <a href=\"https://www.nature.com/news/the-myopia-boom-1.17120\" rel=\"nofollow noreferrer\">featured news story</a>. And if you wonder why all intervention studies in this regard have been conducted in East Asia, <em>Nature</em> has this eye opener on prevalence increase in the region:</p></li>\n</ul>\n\n<p><a href=\"https://i.stack.imgur.com/Pjw9r.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/Pjw9r.png\" alt=\"enter image description here\"></a></p>\n\n<ul>\n<li>Education, at least in some countries, is correlated with a lack of said outdoors light exposure, but it is a much easier proxy to measure than light exposure. Several article have looked at the <a href=\"https://en.wikipedia.org/wiki/Gene%E2%80%93environment_interaction\" rel=\"nofollow noreferrer\">interaction</a> between recently discovered genetic risk factors for myopia and education; the latest one seems to be <a href=\"https://www.nature.com/articles/ncomms11008\" rel=\"nofollow noreferrer\">a meta-analysis</a>, whose main finding is reproduced below in graphical form:</li>\n</ul>\n\n<p><a href=\"https://i.stack.imgur.com/3K6EH.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/3K6EH.png\" alt=\"enter image description here\"></a></p>\n\n<p>The effect appears more significant in Asians than in Europeans.</p>\n\n<p>I should probably mention that education also correlates with near-work exposure, an old favorite hypothesis (advanced centuries ago by Kepler!), but for which <a href=\"https://doi.org/10.1097/OPX.0b013e31819974ae\" rel=\"nofollow noreferrer\">direct evidence is weaker</a>.</p>\n", "score": 4 } ]

[ "eye", "behavior", "lifestyle" ]

[ { "answer_id": 1779, "body": "<p>We are looking at <strong>ventricular hypertrophy</strong> here. </p>\n\n<p>The human heart has a left and a right side. On both sides there are a ventricle and an atrium <a href=\"https://en.wikipedia.org/wiki/Ventricle_(heart)\" rel=\"noreferrer\">(1)</a> <a href=\"https://en.wikipedia.org/wiki/Atrium_(heart)\" rel=\"noreferrer\">(2)</a>. Basically the heart is just a bulk of muscle tissue responsible for circulation and blood flow.</p>\n\n<p>As with any muscle contraction when there is a resistance against the working muscle this leads to muscle growth or hypertrophy. A bad example of such resistance is <strong>a high blood pressure</strong>. Due to the elevated blood pressure, the heart must pump and contract against a continuously present counter force and this leads to a heart muscle hypertrophy, or ventricular hypertrophy <a href=\"https://en.wikipedia.org/wiki/Ventricular_hypertrophy\" rel=\"noreferrer\">(3)</a>. When hypertrophy is due to, say, high blood pressure this hypertrophy or growth is pathological and <em>eventually leads to muscle stiffness and heart failure</em>.</p>\n\n<p>In your case, there is probably also some heart muscle hypertrophy but it is non-pathologic and it can be considered as a healthy \"heart condition\". The principle is the same. When you workout your heart must work more efficiently compared to its resting state and pump more blood to the skeletal muscles due to increased demand for oxygen. <em>Due to the advantageous heart muscle growth your heart is capable of circulating blood more efficiently</em>. </p>\n\n<hr>\n\n<p>Whether the heart muscle growth is pathologic or non-pathologic depends on the concept of afterload <a href=\"https://en.wikipedia.org/wiki/Afterload\" rel=\"noreferrer\">(4)</a>. In a healthy heart the afterload is minimal indicating that the heart \"can rest\" shortly after ejection or ventricular contraction. This results to beneficial hypertrophy. However, if a substantial <strong>afterload</strong> is present, which is the case in elevated blood pressure, the heart \"can't rest\" after contraction but instead is must maintain some level of muscle contraction which results in adverse muscle hypertrophy.</p>\n\n<p>However, in extreme cases the workout can result in some health issues, called an athletic heart syndrome <a href=\"https://en.wikipedia.org/wiki/Athletic_heart_syndrome\" rel=\"noreferrer\">(5)</a>. This is still far less adverse than heart failure.</p>\n", "score": 4 } ]

[ "exercise", "cardiology" ]

[ { "answer_id": 1518, "body": "<p>The only difference it makes to the liver how alcohol is consumed is how high the blood alcohol content becomes and for how long - the other particulars of the beverage will be filtered out by the digestion process. Beverages containing a higher alcohol content will tend to cause a higher peak blood alcohol content because they can be consumed more quickly than the same amount of alcohol in a larger volume, and the more concentrated alcohol will be absorbed from the stomach more quickly. The liver is limited in its capacity to process alcohol. Low blood concentrations of alcohol are efficiently converted into acetate and metabolized, but at high concentrations some of the alcohol is converted into toxic acetaldehyde. Acetaldehyde is thought to cause hangover symptoms and also contribute to liver cell death through oxidative stress (Min, JA; Lee, K; Ki, D. June 2010. <strong>The application of minerals in managing alcohol hangover: a preliminary review.</strong> <em>Current Drug Abuse Reviews</em>, 3(2): 110-115). Replacement of these cells leads over time to enlargement of the liver, accumulation of scar tissue (cirrhosis) and cancer. So avoiding hangover by consuming alcohol in moderation may help avoid liver damage if alcohol is consumed. It is also very important to avoid consumption of acetaminophen with alcohol because processing the alcohol prevents the liver from properly eliminating the acetaminophen, which can cause severe liver damage.</p>\n\n<p>Like the liver, the brain is also only concerned with the concentration of alcohol in the blood and how long it has been that way, in terms of how intoxication is experienced. It will take more alcohol as beer to produce the same level of intoxication as vodka because more of it will have had time to metabolize before the peak blood concentration is reached. The brain also becomes more tolerant to the effects of alcohol as time passes, so that the blood concentration has to be increased over time to maintain the same level of intoxication. So having more drinks to maintain the same experience will be harder on the liver than the initial drinks.</p>\n", "score": 8 } ]

[ "alcohol", "liver" ]

[ { "answer_id": 1701, "body": "<p>Since melatonin is secerned by many glands (pituitary, thyroid, pineal, adrenals, and gonads), it might be a malfunction of one of these. I am not yet a physician, but I suggest you to try to properly address underlying causes. Maybe melatonin supplements are just a palliative which helps controlling symptoms of something else, like an adenosine lack.</p>\n\n<p>That said, let's get to the science: </p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111733/\">This study</a> states that, in relation to development delay risks,</p>\n\n<blockquote>\n <p>[...]Melatonin treatment in children can be sustained over a long period of time without substantial deviation of the development of children with respect to sleep quality, puberty development and mental health scores[...]</p>\n</blockquote>\n\n<p>So it apparently is safe to use it on a regular basis. Just remember it's not helpful when there are wake-up-in-the-middle-of-the-night problems, which are often not idiopathic, they mean something, be it a psychological, health, or anything-else related issue.</p>\n\n<p>Have a nice day</p>\n", "score": 11 } ]

[ "sleep", "pediatrics" ]

[ { "answer_id": 4250, "body": "<h1>An overview of the monoamine neurotransmitters</h1>\n\n<p>Dopamine (DA) is a catecholamine neurotransmitter associated with attention and motivation (9). It is implicated in various other conditions such as psychosis, and Parkinson's disease (9).</p>\n\n<p>Noradrenaline (NE - norepinephrine in North America) is a catecholamine neurotransmitter that plays a role in attention and arousal (9). NE is produced from DA. (5)</p>\n\n<p>Serotonin (5-HT) in an indolamine. 5-HT modulates mood, aggression, dominance, appetite, and sleep (9). </p>\n\n<h1>The pathogenesis of ADHD</h1>\n\n<p>The most prevalent theory of the pathogenesis of ADHD is that it results from an \"deficiency\" of some of the various monoamine neurotransmitters. DA, NE, and to a lesser degree 5-HT, are all implicated (5)(6). DA is the neurotransmitter most heavily associated with ADHD, and its role in the mediation of the disease was primarily elucidated by methylphenidate's effect on dopaminergic neurotransmission (6).</p>\n\n<h1>Pharmacodynamics of antidepressants</h1>\n\n<p>Different antidepressants work through different mechanisms. The major antidepressants are segregated into three classes: Monoamine Oxidase Inhibitors (MAOIs), TCAs, and SSRIs. </p>\n\n<p>MAOIs \"increase\" the levels of all of the monoamine (DA, NE, and 5-HT, among others) neurotransmitters by preventing the deamination of these neurotransmitters by inhibiting the activity of the monoamine oxidase (8).</p>\n\n<p>The affinities for different transporter proteins varies widely in the TCA class. TCAs are generally considered to inhibit the reuptake of NE and 5-HT, although this varies greatly from TCA to TCA. Clomipramine, for instance, has a much higher affinity for the serotonin transporter (SERT) than the noradrenaline transporter (NET) (7). Amitriptyline has relatively balanced 5-HT and NE action, whereas desipramine and nortriptyline very selective for NET. (7)</p>\n\n<p>SSRIs (as the name suggests) are most potent at inhibiting SERT. </p>\n\n<h1>The role of antidepressants in the treatment of ADHD</h1>\n\n<p>Tricyclic Antidepressants (TCAs) are the main class of antidepressants used to treat ADHD typically in conjunction with a stimulant. Most TCAs inhibit the reuptake of NE into the presynaptic clef. This is a mode of action shared with stimulant medications. Their efficacy in the remediation of ADHD symptoms is inferior to that of the stimulants (3). Due to the lack of action on dopamine neurotransmission, TCAs only treat the hyperactive element of ADHD - in other words, they often fail to improve concentration (3). Desipramine, because of its selectivity for NE reuptake inhibition, is the TCA most frequently used for ADHD (2). </p>\n\n<p>Selective Serotonin Reuptake Inhibitors (SSRIs) such as fluoxetine are occasionally used in conjuction with stimulants (3). Contaminant use of fluoxetine with a stimulant results in a significant increase in school performance, and attenuation of irritability: <em>\"things that used to bother me a whole don't seem to bother me much anymore\"</em> (3). Low serotonin is associated with impulsivity and aggression (3). It's hypothesized in (3) that fluoxetine may influence the brain's response to DA. </p>\n\n<h1>References</h1>\n\n<ol>\n<li>Treatment of adults with attention-deficit/hyperactivity disorder, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1938791\" rel=\"nofollow noreferrer\">http://www.ncbi.nlm.nih.gov/pubmed/1938791</a></li>\n<li>Tricyclic antidepressants for attention deficit hyperactivity disorder (ADHD) in children and adolescents. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25238582\" rel=\"nofollow noreferrer\">http://www.ncbi.nlm.nih.gov/pubmed/25238582</a></li>\n<li>Fluoxetine and methylphenidate in combination for treatment of attention deficit disorder and comorbid depressive disorder, <a href=\"http://www.drthomasebrown.com/pdfs/fluoxetine.pdf\" rel=\"nofollow noreferrer\">http://www.drthomasebrown.com/pdfs/fluoxetine.pdf</a></li>\n<li>Treatment of ADHD with fluoxetine: a preliminary trial, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1938791\" rel=\"nofollow noreferrer\">http://www.ncbi.nlm.nih.gov/pubmed/1938791</a></li>\n<li>Functional Roles of Norepinephrine and Dopamine in ADHD <a href=\"http://www.medscape.org/viewarticle/523887\" rel=\"nofollow noreferrer\">http://www.medscape.org/viewarticle/523887</a></li>\n<li>Attention-deficit hyperactivity disorder (ADHD):an updated review of the essential facts</li>\n<li>Tricyclic antidepressant pharmacology and therapeutic drug interactions updated <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014120/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014120/</a></li>\n<li>The Role of Monoamine Oxidase Inhibitors in Current Psychiatric Practice</li>\n<li>Chapter 12: Biogenic Amine Neurotransmitters <a href=\"http://neuroscience.uth.tmc.edu/s1/chapter12.html\" rel=\"nofollow noreferrer\">http://neuroscience.uth.tmc.edu/s1/chapter12.html</a></li>\n</ol>\n", "score": 6 } ]

[ "medications", "mental-health", "depression", "adhd", "antidepressants" ]

[ { "answer_id": 11743, "body": "\n<h1>A scholarly report discusses the matter</h1>\n<p>Some years ago, a scholarly report was published. The report's <a href=\"https://www.ifh-homehygiene.org/system/files_force/publications/Effectiveness_of_laundering_IFHreport_21102013.pdf#page=52\" rel=\"nofollow noreferrer\">&quot;Appendix A&quot;</a> discusses, among other things, how to clean your laundry if there's a risk that it may be somewhat contagious.</p>\n<h1>The advice given</h1>\n<p>The report advises:</p>\n<ul>\n<li>Whenever you do laundry, add some <strong>activated oxygen bleach (AOB)</strong>.\n<ul>\n<li>Notes: You can use standalone AOB, or a detergent with AOB included. <a href=\"https://medicalsciences.stackexchange.com/questions/12053/if-you-have-fungus-e-g-athletes-foot-its-wise-to-add-activated-oxygen-blea\">This link</a> discusses your options. In the US, <strong>Tide powder</strong> is one good choice. Certain products are probably <strong>not</strong> good disinfectants, including Tide liquid, Tide pods, and OxiClean.</li>\n</ul>\n</li>\n<li>If possible, also do laundry at <strong>140 °F (60 °C)</strong>.\n<ul>\n<li>Note: This may shrink and/or destroy certain items. <a href=\"https://www.sudsuplaundry.com/understanding-laundry-temperatures-know/\" rel=\"nofollow noreferrer\">(Source.)</a> Read their care labels.</li>\n</ul>\n</li>\n<li>Use the <strong>regular cycle</strong>. Don't enable &quot;quick wash&quot;, &quot;water saving&quot;, or any other environmentally-friendly options.</li>\n<li>Make sure each item goes through the rinse and spin cycles <strong>at least twice</strong>. Preferably three times.</li>\n<li>It's best to wash items belonging to the infected family member in <strong>separate loads</strong> from everyone else's laundry.</li>\n<li>If you can also dry the items in <strong>sunlight</strong>, this is an extra bonus.</li>\n<li>The report also gives <strong>other advice</strong>; please see <a href=\"https://www.ifh-homehygiene.org/system/files_force/publications/Effectiveness_of_laundering_IFHreport_21102013.pdf#page=52\" rel=\"nofollow noreferrer\">here</a>.</li>\n</ul>\n<h1>Water temperature</h1>\n<p>In some countries (including the US and certain others), if you want to wash clothing at 140 °F (60 °C), there's a problem.</p>\n<p>An <a href=\"http://bottomlineinc.com/laundry-error-to-blame-for-persistent-athletes-foot-and-toenail-fungus/\" rel=\"nofollow noreferrer\">article</a> on the Bottom Line Inc. website states that, in these countries,</p>\n<blockquote>\n<p>household water heaters typically are set to 120 °F [50 °C] to minimize the risk of scalding.</p>\n</blockquote>\n<p>The article suggests three possible workarounds.</p>\n<ul>\n<li><p>One (<strong>dangerous</strong>) workaround would be to raise your water heater's temperature to 140 °F (60 °C). But this is a dangerously-high setting. <a href=\"http://www.npr.org/sections/health-shots/2013/03/28/175584883/many-hot-water-heaters-set-too-high-upping-burn-risk\" rel=\"nofollow noreferrer\">(Source.)</a> It may also be illegal in your jurisdiction. <a href=\"http://inspectapedia.com/plumbing/Hot_Water_Temperature_Laws.php\" rel=\"nofollow noreferrer\">(Source.)</a> Water at 120 °F (50 °C) takes 5-10 minutes to cause a third-degree burn; but water at 140 °F (60 °C) takes just 3-5 seconds. <a href=\"http://www.terrylove.com/forums/index.php?threads/honeywell-am-1-thermostatic-mixing-valves-water-heater-tempering.45651/\" rel=\"nofollow noreferrer\">(Source.)</a> Third-degree burns sometimes kill people. <a href=\"https://www.reddit.com/r/explainlikeimfive/comments/28j9zp/eli5_why_when_someone_is_badly_burnt_do_they_die/cibgrh9/\" rel=\"nofollow noreferrer\">(Source.)</a> Maybe I should email the Bottom Line Inc. and suggest that they revise their article.</p>\n</li>\n<li><p>Another workaround might be to pour a <strong>kettleful of boiling water</strong> into your top-loading washer shortly before it's finished filling.</p>\n</li>\n<li><p>A third workaround is to use a washing machine with a <strong>water-temperature-boosting feature</strong>, &quot;such as the Whirlpool Front-Load Washer with Deep-Clean Steam, model #WFW86HEBW, which can get the water up to 150 °F [65 °C]&quot;.</p>\n</li>\n</ul>\n", "score": 9 }, { "answer_id": 21235, "body": "<p>Bleach was never an option for me due to the discoloring of the fabric, but after several years I've noticed a major improvement using a laundry sanitizer.</p>\n<p>Note that you need to let your clothes soak in the product for at least 20 minutes, and the longer the better.</p>\n", "score": 0 } ]

[ "clothes", "athletes-foot", "bleach", "detergent", "jock-itch-tinea-cruris" ]

[ { "answer_id": 7159, "body": "<p>No one likes CVS, and computer glasses are <a href=\"http://www.allaboutvision.com/cvs/computer_glasses.htm\" rel=\"nofollow\">said</a> to increase contrast and decrease glare to alleviate eye stress. If you are sure you will be using the computer in the future for prolonged periods and have <em>considerable</em> discomfort, it will be worth the investment for eye strain relief and ultimately less magnification.</p>\n", "score": 3 }, { "answer_id": 11237, "body": "<p>According to eye care providers, computer glasses designed for digital screens which can help alleviate many of the factors which cause eye strain symptoms, although do not completely prevent it.</p>\n<p>For example they may help the eye to adjust to intermediate-distance objects such as computer screens. There are some with an antireflective coating which may help with eye strain by softening the glare of harsh indoor and outdoor lighting and improving the contract of digital content. There are also lenses that can absorb harmful blue light (they're infused with melanin or use a blue-light filtering coating.</p>\n<p>Here are the type of lens designed for computer screens:</p>\n<ul>\n<li><p>Single Vision Lenses</p>\n<blockquote>\n<p>A prescription lens that is optimized for individuals’ computer screen working distance. This is\nthe least flexible lens option as the extent of vision (depth of field) is very limited.</p>\n</blockquote>\n</li>\n<li><p>Progressive Lenses</p>\n<blockquote>\n<p>A solution for your everyday visual needs that addresses far, intermediate and near vision.\nThese lenses are a good solution for those with limited computer use. Due to a limited intermediate vision width of\nfield, they should not be worn for prolonged computer time.</p>\n</blockquote>\n</li>\n<li><p>Computer Lenses</p>\n<blockquote>\n<p>A work station solution for those that are on a computer for more than two hours a day. With a\nwide intermediate and near area, these lenses have limited room-length viewing distance.</p>\n</blockquote>\n</li>\n</ul>\n<p>And type of treatments and tints:</p>\n<ul>\n<li><p>Anti-Reflective Coating</p>\n<blockquote>\n<p>Reduces reflection and glare from indoor and outdoor lighting sources in addition to ghost\nreflections from light sources that can contribute to visual noise and potential visual distractions.</p>\n</blockquote>\n</li>\n<li><p>HEV Coatings</p>\n<blockquote>\n<p>Reduces reflection while blocking out potentially harmful HEV light. Some fluorescent light and\nbacklit LED devices produce a lot of light at the blue end of the spectrum.</p>\n</blockquote>\n</li>\n<li><p>Color Filters</p>\n<blockquote>\n<p>May filter out harmful blue and violet light that is emitted by many digital devices. These filters may\nalso be prescribed to reduce harsh office lighting and balance colors.</p>\n</blockquote>\n</li>\n</ul>\n<p>To determine whether you need such glasses and they would work in your case, it is best to schedule a comprehensive eye exam to determine whether such prescription is needed.</p>\n<hr />\n<p>Source: <a href=\"https://www.thevisioncouncil.org/sites/default/files/TVCDigitEYEzedReport2013.pdf\" rel=\"nofollow noreferrer\">Digiteyezed - The daily impack of digital screens on the eye health of Americans</a></p>\n", "score": 1 }, { "answer_id": 26264, "body": "<p>From my experience with chronic eye strain and subsequent recovery, computer glasses didn't help, because the blue light was not the reason for strain (<a href=\"https://pubmed.ncbi.nlm.nih.gov/30570598/\" rel=\"nofollow noreferrer\">ref1</a>, <a href=\"https://pubmed.ncbi.nlm.nih.gov/32007978/\" rel=\"nofollow noreferrer\">ref2</a>). Eye drops and all the other methods suggested by people didn't help either. The strain was caused by lack of rest for the intraocular and extraocular muscles. So there were three things that cured the strain:</p>\n<ol>\n<li>Getting 8 hours of <strong>uninterrupted</strong> sleep each night.</li>\n<li>Closing the eyes after 20 minutes of computer use, and relaxing the neck muscles and face muscles.</li>\n<li>Getting a well balanced diet of properly cooked food. Food that's not properly cooked or burnt will cause stomach discomfort, leading to sleep loss (and sleep loss is one of the major reasons for fatigue-related strain). Also, get sufficient protein in your diet. Muscles need protein. A well balanced diet is necessary.</li>\n</ol>\n", "score": 0 } ]

[ "eye", "effectiveness", "vision", "stress", "glasses" ]

[ { "answer_id": 17649, "body": "<h3>These dark circles can likely be attributed to vascular network prominence caused by hollowing of the contents of the orbital rim, pigmentary changes in the periorbital area caused by extravasated hemoglobin and its breakdown products (bilirubin and biliverdin), or to visibly accumulating fluid in the lower eyelid due to local processes such as atopy or systemic fluid retention.</h3>\n\n<p>Dark circles under the eyes are very literally representative of infraorbital (or periorbital/periocular) hyperpigmentation. I was able to find literature pretty quickly on this subject dating all the way back to the '60s:</p>\n\n<blockquote>\n <p><a href=\"http://journals.sagepub.com/doi/abs/10.1177/000992286600501106?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub%3dpubmed\" rel=\"nofollow noreferrer\"><strong>\"Dark Circles Under the Eyes in Children.\" Meyer B. Marks. <em>Clinical Pediatrics</em>. 1966.</strong></a></p>\n \n <p>Dark\n discolorations \n or \n shadows \n under\n the \n eyes \n as \n seen \n in \n some \n children \n are \n often\n ascribed \n to \n fatigue \n or \n sleeplessness. \n With \n older\n children \n and \n even \n in \n adults \n a \n popular \n notion\n is \n to \n attribute \n these \n to \n chronic \n eyestrain. \n With\n an \n adolescent \n girl \n at \n menarche \n the \n mother\n may \n associate \n them \n with \n menstruation.\n Many \n of \n the \n bluish-black \n discolorations \n in\n the \n lower \n orbitopalpebral \n grooves \n of \n children\n – termed \"allergic \n shiners\" – result \n from \n long-\n standing \n perennial \n nasal \n allergy.\n They \n are \n rarely \n seen \n in \n the \n first \n year \n of \n life\n unless \n the \n infant \n had \n nasal \n obstruction \n with\n accompanying \n mouth-breathing \n from \n birth.\n Children \n with \n uncomplicated \n seasonal \n allergic\n rhinitis \n do \n not \n have \n allergic \n shiners.</p>\n</blockquote>\n\n<p>This early paper (which mentions allergies as the cause of these dark circles) alludes to sleeplessness or fatigue as being another cause of infraorbital hyperpigmentation. Skipping several decades of research and progress, there are a number of useful, modern review papers on this subject (<strong>emphasis</strong> mine):</p>\n\n<blockquote>\n <p><a href=\"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1473-2165.2007.00324.x\" rel=\"nofollow noreferrer\"><strong>\"What causes dark circles under the eyes?\" Fernanda Magagnin Freitag,\n Tania Ferreira Cestari. <em>Journal of Cosmetic Dermatology.</em> 2007.</strong></a></p>\n \n <p>Dark rings under the eyes are defined as bilateral, round,\n homogeneous pigment macules on the infraorbital regions.\n There is no doubt that they are worsened by general\n fatigue, especially lack of sleep. This idea is corroborated\n by the daily fluctuation of the lesions intensity, according\n to the patient status. For this reason, they have been\n regarded as a mere physiologic phenomenon.\n Dark circles are more pronounced in certain ethnic groups and\n are also frequently seen in multiple members of the same\n family. These hereditary observations raise a question:\n are there any anatomic or histological characteristics\n in these populations that could give us a reasonable\n etiologic explanation?\n Histological characteristics of infraorbital darkening\n suggest that they are caused by <strong>multiple etiologic factors</strong>\n that include <strong>dermal melanin deposition, postinflammatory\n hyperpigmentation secondary to atopic or allergic contact\n dermatitis, periorbital edema, superficial location of\n vasculature, and shadowing due to skin laxity</strong>. </p>\n \n <p>Despite its prevalence and cosmetic importance, there are\n few published studies in the scientific literature about\n dark circles. Even a good definition of this condition is\n lacking. We think the term \n infraorbital ring-shaped melanosis\n proposed by Watanabe et al. does not encompass its\n etiology in a global manner.\n As there is neither a general understanding about\n dark circles pathogenesis nor a consensus about the\n major responsible features, treatments are chosen in a\n simplified way, rendering suboptimal results most of\n the time. It is important to identify the specific anatomic\n problem of each patient in order to individualize treatment.</p>\n</blockquote>\n\n<p>This gets closer to a direct answer and offers several possible etiologies (<strong>bolded</strong>) for infraorbital hyperpigmentation. These are further clarified in the context of sleep by publications from this year:</p>\n\n<blockquote>\n <p><a href=\"http://www.pigmentinternational.com/article.asp?issn=2349-5847;year=2018;volume=5;issue=1;spage=34;epage=42;aulast=Chatterjee\" rel=\"nofollow noreferrer\"><strong>\"A study of epidemiological, etiological, and clinicopathological factors in periocular hyperpigmentation.\" M Chatterjee, B Suwal, A Malik, B V. <em>Journal of Cosmetic Dermatology.</em> 2018.</strong></a></p>\n \n <p><strong>Conclusion:</strong>\n Periocular darkening was predominantly not due to pigment, but rather due to cutaneous laxity and vascular visibility through\n thin skin. Most of them with pigment had it in the dermis. Clinical dermal pigmentation correlated well with histology, unlike epidermal\n pigmentation. Iron and amyloid were not significant as etiological factors in our patients.</p>\n \n <p><a href=\"http://www.pigmentinternational.com/temp/PigmentInt511-8315215_230552.pdf\" rel=\"nofollow noreferrer\"><strong>\"Periorbital hyperpigmentation − An overview of the enigmatous condition.\"<br>\n Manju Daroach, Muthu S Kumaran. <em>Pigment International.</em> 2018.</strong></a></p>\n \n <p>Periocular dark circles may appear because of various\n anatomic factors such as architecture of facial ligaments,\n the bony facial structure, midface soft tissue including the \n prominence of the orbicularis oculi muscle. Because of ageing,\n there is a loss of facial fat leading to inflexible ligaments\n causing hollowing effect on orbital rim. There is worsening of\n shadowing duetohollowness,which is mainly seen in the tear\n trough area in inferomedial orbit. The thin eyelid skin\n contributes to the prominence of the underlying soft tissue\n and subcutaneous vascular network and the orbicularis oculi\n muscle, due to which the overlying skin appears dark. </p>\n \n <p>Visible pigmentary changes in periorbital area may be due to\n extravasated hemoglobin and its breakdown products\n bilirubin and biliverdin. A variety of pathologic and\n age-related processes result in the increased permeability\n of the local vasculature resulting in these pigmentary\n changes. The lower eyelid tissues may have an increased\n tendency to accumulate fluid due to local processes such as\n atopy as well as systemic fluid retention and can be limited\n inferiorly by the orbital rim because of the cutaneous\n ligaments. This fluid often takes on a purplish color due\n to the prominent role of the orbicularis muscle in the lower\n eyelid. Medical disorders including disorders of liver,\n heart, thyroid or kidney, hereditary blood disorders,\n vitamin K deficiency.</p>\n</blockquote>\n\n<p>For a more complete analysis of the different contributing factors to infraorbital dark circles, check out this review from 2016:</p>\n\n<blockquote>\n <p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4924417/\" rel=\"nofollow noreferrer\"><strong>\"Infraorbital Dark Circles: A Review of the Pathogenesis, Evaluation and Treatment.\" Ivan Vrcek, Omar Ozgur, and Tanuj Nakra. <em>Journal of Cutaneous and Aesthetic Surgery.</em> 2016.</strong></a></p>\n \n <p>Infraorbital dark circles are caused by a variety of anatomic features, with contributions from the skin, subcutaneous tissues, orbicularis muscle, vasculature and ligamentous architecture of the lower eyelid and cheek. A detailed understanding of the regional anatomy is crucial to the management of dark circles, which encompasses a wide variety of modalities.</p>\n</blockquote>\n\n<h3>This might not be a totally satisfying answer, but it's not as simple as a single source of pigmentation resulting in dark circles under the eyes. Even though there are many contributing factors, we still use general periorbital hyperpigmentation as an <a href=\"https://content.iospress.com/articles/integrated-computer-aided-engineering/ica00476\" rel=\"nofollow noreferrer\">identifier of fatigue</a>, since the various factors (usually) cumulatively represent sleeplessness.</h3>\n", "score": 6 } ]

[ "dermatology", "sleep", "body-fat", "sleep-deprivation", "dehydration" ]

[ { "answer_id": 21640, "body": "<p>There is a study from Chinese scientists from Bejing on this question:<br>\n<a href=\"https://www.biorxiv.org/content/10.1101/2020.03.13.990226v1.full.pdf\" rel=\"noreferrer\">Reinfection could not occur in SARS-CoV-2 infected rhesus macaques</a></p>\n\n<blockquote>\n <p>Combined with the follow-up virologic, radiological and pathological findings, the monkeys with re-exposure showed no recurrence of COVID-19, similarly to the infected monkey without rechallenge. Taken together, our results indicated that the primary SARS-CoV-2 infection could protect from subsequent exposures, which have the reference of prognosis of the disease and vital implications for vaccine design.</p>\n</blockquote>\n\n<p>One has to state that with four monkeys the statistics is very low, though.</p>\n\n<p>There is, however, also a risk for relapse and further mutations of the virus as already pointed out by brasscup and Alexei.</p>\n", "score": 6 }, { "answer_id": 21539, "body": "<p>This article from the UK Independent is a fair round-up of differing opinions on whether contracting the virus conveys immunity:\n<a href=\"https://www.independent.co.uk/life-style/health-and-families/coronavirus-immunity-reinfection-get-covid-19-twice-sick-spread-relapse-a9400691.html\" rel=\"nofollow noreferrer\">https://www.independent.co.uk/life-style/health-and-families/coronavirus-immunity-reinfection-get-covid-19-twice-sick-spread-relapse-a9400691.html</a>\nThere have been reports of patients getting reinfected following recovery. The most discussed occured this month. In Osaka, a tour bus operator in her 40s tested positive for COVID-19 for a second time. She was first diagnosed with coronavirus in late January and was discharged from hospital on February 1.\nBut there is disagreement as to whether it is an entirely new infection or a relapse.</p>\n", "score": 2 }, { "answer_id": 23559, "body": "<p>As of May 2020, data are very limited on whether infection confers immunity, let alone long term immunity. </p>\n\n<p>While COVID-19 related coronavirus is still being studied, a similar SARS coronavirus from 2003 has been studied.</p>\n\n<p>In a 2011 research study, scientists found that certain types of immunity called T cell memory did persist, while others (B cell related) did not. This immune memory response was more marked in severe infections as well. While this is promising that the human immune system can “remember” and potentially defend against repeat infection, the authors were careful to note that even T cell memory immunity did not necessarily mean the individuals were immune from reinfection.</p>\n\n<p>Source: <a href=\"https://www.jimmunol.org/content/jimmunol/186/12/7264.full.pdf\" rel=\"nofollow noreferrer\">https://www.jimmunol.org/content/jimmunol/186/12/7264.full.pdf</a></p>\n", "score": 2 }, { "answer_id": 21237, "body": "<p>I would take a bold personal statement (AFAIK as of now there are no accepted scientific knowledge of that matter) that they will be immune from specific mutation, but there are already more than one, see my question I just asked: </p>\n\n<p><a href=\"https://medicalsciences.stackexchange.com/questions/21236/how-virus-is-distinguished-by-pcr-test-different-mutations-of-sars-cov-2\">How virus is distinguished by PCR test (different mutations of sars-cov-2)?</a>. </p>\n\n<p>Link to news article: </p>\n\n<p><a href=\"https://www.cnbc.com/2020/03/04/coronavirus-chinese-scientists-identify-two-types-covid-19.html\" rel=\"nofollow noreferrer\">https://www.cnbc.com/2020/03/04/coronavirus-chinese-scientists-identify-two-types-covid-19.html</a></p>\n\n<p>So these reported re-infections could be infections by other mutation of the virus.</p>\n", "score": 1 }, { "answer_id": 23084, "body": "<p>Blood samples for antibodies against the novel corona virus are tested in several Swiss laboratories.</p>\n\n<p><em>The Inselspital Bern is currently not doing so because the quality of the results has not yet been adequately investigated, says the director of the University Clinic for Infectious Diseases.\nThe problem is that detection of antibodies in the blood does not necessarily mean that someone is also immune.</em></p>\n\n<p><em>Another problem in the use of blood tests as part of an exit strategy arises in terms of capacity: there is currently a shortage of test material in large quantities. This is confirmed by the Laboratory Medical Center Dr. Risch, where the first blood tests have recently been carried out in the laboratories in Buchs SG. The hospital staff, nursing staff and law enforcement officers have priority there, says Lorenz Risch, Chairman of the Board of Directors and Medical Director, towards SRF. Theoretically, you would have the capacity for around 1000 tests per day, but you can currently only make around a hundred in one or two days because the suppliers from Germany and the United States could no longer supply the so-called reagents.</em></p>\n\n<p><a href=\"https://www.srf.ch/news/schweiz/antikoerpertest-bei-corona-der-qualitaetsnachweis-ist-fuer-uns-noch-nicht-gegeben\" rel=\"nofollow noreferrer\">https://www.srf.ch/news/schweiz/antikoerpertest-bei-corona-der-qualitaetsnachweis-ist-fuer-uns-noch-nicht-gegeben</a></p>\n\n<p>The chief of the hospital says:</p>\n\n<p><strong>Antibody test at corona: the proof of quality is not yet given.</strong></p>\n", "score": 1 }, { "answer_id": 23531, "body": "<p>There is one report i am aware of, this has not been entirely confirmed. Information changes rapidly in a situation like this. The best we can do is take precautions, and wait for the experts to speak on a position of authority. Weather its possible that a virus in general can do this? Yes. It is also possible for it to hide in reservoirs that the immune system cant get at easily. </p>\n\n<p><a href=\"https://qz.com/1837798/why-some-covid-19-patients-might-have-tested-positive-twice/\" rel=\"nofollow noreferrer\">https://qz.com/1837798/why-some-covid-19-patients-might-have-tested-positive-twice/</a></p>\n", "score": 1 } ]

[ "immune-system", "covid-19" ]

[ { "answer_id": 23061, "body": "<p>What your government is proposing is a lot less than what was actually done in China. There, and perhaps that is still the case, large numbers of asymptomatic infected people were housed together in halls with only social separation between them, and masks to prevent others from infecting others.</p>\n\n<p>Your government is proposing to house the asymptomatic infected in hotels, presumably in separate rooms.</p>\n\n<p>We know that people who are infected because they have virus identified using PCR swabs of their upper airways. CT scans can show pulmonary lesions present even without cough or fever. And even speaking can aerosolize virus though you are likely most infective at about days 4-5 before your own antibody production has ramped up significantly.</p>\n\n<p>So, it's likely you are exhaling virus, and inhaling again the virus that you exhale, as well as spreading virus in your blood to other tissues. It seems less likely that you're going to inhale a viral load that already exceeds the amount of virus coating your mucus membranes and alveloli. At least you will have some antibody production after day 5 or so on average to provide some protection.</p>\n\n<p>Note also that even within family groups housed together in Guangzhou, the incidence of cross infection was only 10%.</p>\n\n<p>And there are likely to be host factors at work. We know that women and younger people have a less severe course generally. So, even with a higher viral load on re-exposure, that may not change the underlying host factors that might =give them some protection eg. higher levels of ACE2 receptors, Group O blood group etc.</p>\n\n<p><a href=\"https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf\" rel=\"noreferrer\">https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf</a></p>\n", "score": 14 }, { "answer_id": 23060, "body": "<p>Doing such an experiment on humans would obviously be unethical in the present circumstances. There has been <a href=\"https://www.livescience.com/monkeys-cannot-get-reinfected-with-coronavirus-study.html\" rel=\"nofollow noreferrer\">a report</a> that monkeys who recovered and were later re-infected with mega-doses of the Covid-19 virus didn't get sick again. This is not terribly conclusive, because monkeys don't get severe symptoms from SARS like we do, <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC521815/\" rel=\"nofollow noreferrer\">for example</a>. (SARS is the closest relevant relative to the Covid-19 virus aka SARS-CoV-2.)</p>\n<p>Immunity to a pathogen, <a href=\"https://www.virology.ws/2009/12/28/reinfection-with-2009-influenza-h1n1/\" rel=\"nofollow noreferrer\">in general</a> takes about 3-4 weeks to develop to develop fully, so if you [get] re-infect[ed] with a larger dose within this window, even a after a vaccine, you can cause/get the disease, although it's apparently a pretty rare occurrence.</p>\n<blockquote>\n<p>These individuals were likely resusceptible to reinfection with the same strain of influenza virus due to a confluence of unusual events. First, all three were reinfected within three weeks, before their primary adaptive response had sufficiently matured. Another contributing factor was the high level of circulation of the pandemic strain. [...]</p>\n<p>Could reinfection also occur after immunization with influenza vaccine? Yes, if the immunized individual encounters the virus before the primary antibody response matures, which occurs in 3-4 weeks. This is more likely to occur during pandemic influenza when circulation of the virus is more extensive than in non-pandemic years.</p>\n<p>[Citing:]</p>\n<p>Perez CM, Ferres M, &amp; Labarca JA (2010). Pandemic (H1N1) 2009 Reinfection, Chile. Emerging infectious diseases, 16 (1), 156-7 PMID: 20031070</p>\n</blockquote>\n<hr />\n<p>About the Fangcang-style hospitals (i.e. make-shift hospitals for those with mild or asymptomatic infections), which China <a href=\"https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30744-3/fulltext\" rel=\"nofollow noreferrer\">says it closed</a> the last one on March 10 (after there were 13 opened in Wuhan at the peak); it <a href=\"https://politics.stackexchange.com/questions/52494/are-any-countries-besides-china-planning-to-use-fangcang-hospitals-to-relocate\">turns out</a> they used now in other countries, and they are even a <a href=\"https://www.who.int/publications-detail/home-care-for-patients-with-suspected-novel-coronavirus-(ncov)-infection-presenting-with-mild-symptoms-and-management-of-contacts\" rel=\"nofollow noreferrer\">WHO recommendation</a> of sorts (as of March 17):</p>\n<blockquote>\n<p>WHO recommends that all laboratory confirmed cases be isolated and cared for in a health care facility.</p>\n<p>[...]</p>\n<p>If all mild cases cannot be isolated in health facilities, then those with mild illness and no risk factors may need to be isolated in non-traditional facilities, such as repurposed hotels, stadiums or gymnasiums where they can remain until their symptoms resolve and laboratory tests for COVID-19 virus are negative.</p>\n</blockquote>\n<p>According to the (April 2) <a href=\"https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30744-3/fulltext\" rel=\"nofollow noreferrer\"><em>Lancet</em> paper</a> on Fangcang hospitals, they Chinese took various precautions to prevent cross-infection with other diseases in such settings. How strictly these measures have been implemented and how well replicated in non-Chines Fangcangs elsewhere, I won't venture to comment here, but <a href=\"https://edition.cnn.com/2020/02/22/asia/china-coronavirus-roundup-intl-hnk/index.html\" rel=\"nofollow noreferrer\">CNN had</a> a somewhat disparaging article about Fangcang hospitals back in February, outlining their shortcomings. Since then, the US has been arranging similarly looking facilities <a href=\"https://www.youtube.com/watch?v=ncC6KnVzKu0\" rel=\"nofollow noreferrer\">in the NY area</a>, but I don't know how they intend to use them.</p>\n", "score": 1 }, { "answer_id": 23069, "body": "<p>You may find this article to be helpful in some way. Dr. Siddhartha Mukharjee The New Yorker April 6 2020 issue. “How does the Coronavirus Behave Inside a Patient”</p>\n\n<p>The title I think is a bit misleading. The article does not cover the whole course of the illness! I think. It is interesting <a href=\"https://www.newyorker.com/magazine/2020/04/06/how-does-the-coronavirus-behave-inside-a-patient\" rel=\"nofollow noreferrer\">https://www.newyorker.com/magazine/2020/04/06/how-does-the-coronavirus-behave-inside-a-patient</a></p>\n\n<p>This covers more first, early, early repeat exposures. </p>\n\n<p>The inoculum viral load and such is discussed. </p>\n\n<p>I don’t think this a perfect answer to OP’s question but it may be helpful in some way. </p>\n\n<p>Author bio: <a href=\"https://en.m.wikipedia.org/wiki/Siddhartha_Mukherjee\" rel=\"nofollow noreferrer\">https://en.m.wikipedia.org/wiki/Siddhartha_Mukherjee</a></p>\n", "score": 1 } ]

[ "covid-19", "infection", "virus", "infectious-diseases", "sars-cov-2" ]

[ { "answer_id": 23326, "body": "<p>The only approved inhaled vaccine is the flu vaccine delivered intra-nasally. It uses a live attenuated virus. There are a whole list of people who should not receive it because it's a live virus, and it works better for children, but only is 40% effective for adults.</p>\n\n<p>The main issue is</p>\n\n<blockquote>\n <p>The intranasal LAIV, recommended for children above the age of 2 years, induces a broader immune response wherein protection <strong>is not antibody mediated</strong> and probably involves undefined multiple correlates of protection.</p>\n</blockquote>\n\n<p>and that's with a live virus.</p>\n\n<p>How well would a dead inhaled virus work? Well, we have some data from MERS that suggests that vaccination with whole dead virus can increase lung pathology when exposed to live virus.</p>\n\n<blockquote>\n <p>The implication of the current study is that application of an inactivated MERS-CoV vaccine for prevention of MERS in humans may carry a risk for lung immunopathology if subsequently exposed to MERS-CoV. The study also leads us to suggest that the extensive background of preclinical experience with inactivated SARS-CoV vaccines may be applicable to inactivated MERS-CoV vaccines.</p>\n</blockquote>\n\n<p>So, your cheap vaccine may increase your risk of death or disease when exposed to the live virus.</p>\n\n<p>Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines\n<a href=\"https://www.cdc.gov/flu/prevent/nasalspray.htm\" rel=\"noreferrer\">https://www.cdc.gov/flu/prevent/nasalspray.htm</a></p>\n\n<p>Immunization with inactivated Middle East Respiratory Syndrome coronavirus vaccine leads to lung immunopathology on challenge with live virus\n<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5027702/\" rel=\"noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5027702/</a></p>\n", "score": 19 }, { "answer_id": 24308, "body": "<p>It wouldn't be consistent. (as some of the commenters pointed out).</p>\n<p>Here are some numbers:</p>\n<ul>\n<li><p>The concentration of virus in sputum can vary by a factor of 10^5.\n(<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7224694/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7224694/</a> for count of RNA in sputum)</p>\n</li>\n<li><p>Best guess is that 100-1000 RNA copies is a &quot;quanta&quot; in the Wills-Riley Model (<a href=\"http://tinyurl.com/covid-estimator\" rel=\"nofollow noreferrer\">http://tinyurl.com/covid-estimator</a>)</p>\n</li>\n<li><p>If it's known how many RNA copies is good to generate immune response but not disease, it's very hard to get the right level.</p>\n</li>\n<li><p>There will be variation in immune response / disease contracting.</p>\n</li>\n</ul>\n<p>But, this doesn't rule it out as possible. In fact, nothing can prove it's impossible except running every variation of what you're saying. To prove it's possible, you would need to run the controlled experiment.</p>\n<p>But that experiment would be considered unethical.</p>\n<p>You could try it in rats or mice first. But there is no good animal model for COVID19 right now (from what I read).</p>\n", "score": 2 } ]

[ "covid-19", "virus", "vaccination", "infectious-diseases", "antibodies" ]

[ { "answer_id": 24073, "body": "<p>People could develop antibodies from natural exposure to the virus. The vaccine is trying to cause antibodies to exist in more people (and/or more strongly) than would express them naturally, therefore a good comparison group is a sample taken randomly in the same way as those getting the vaccine: a placebo group.</p>\n<p>At the same time, these trials tend to assess safety outcomes; again, to assess safety you want to know that effects are <em>no worse</em> than those in some comparison population. Comparing to placebo is typically a gold standard for this comparison.</p>\n<p>You're right that a placebo wouldn't be as necessary if we could prevent random exposure, but in the middle of a pandemic that isn't feasible.</p>\n", "score": 35 }, { "answer_id": 24078, "body": "<p>People in the control group will behave differently if they know they're in the control group.</p>\n<p>For example, it's not unreasonable to expect people will do less social distancing once they're vaccinated. This will increase their chances of being exposed to the virus.</p>\n", "score": 13 }, { "answer_id": 24074, "body": "<p>Good question. A phase I trial normally has small numbers, is purely sized to test safety, and it would have no placebo arm.\nWith side effects and antibodies are end points, and a placebo group, this would more often be called a <strong>combined phase I/II trial</strong>.</p>\n<p>The purpose of the placebo should be to compare the proportion of side effects and antibodies in the vaccine arm and those in the placebo arm. However with only 20 people in each arm, this seems a bit, ehm, optimistic.</p>\n<p>Imagine if 4 of the vaccinated people report a sore arm, 2 a headache and sore throat, and 2 a fever, that might be unacceptable. But headache and sore throat are common, and as well as fever during winter-time, when colds and influenza are running around. So I expect the reason for the placebo group is to be able to partially compensate for influenza-like illnesses in the community, so they could suggest that some of the reported vaccine side effects aren't from the vaccine. (Note, you can't just subtract one from the other -- with that few people in each group, random variation will be high, so it may be that more of the &quot;placebo&quot; folks got unlucky... but the vaccine still causes fevers in 10% of the vaccinated folks).</p>\n<p>As far as antibodies, you're right -- assuming that in Adelaide, Australia the rates of COVID-19 are very low, then only the vaccinated volunteers could develop antibodies. But what if one of the vaccinated people gets a mild infection naturally? Then you'd better hope that 1-2 of the placebo volunteers do as well, so that you can know the antibody response isn't necessarily from the vaccine.</p>\n<p>Or what if the antibody test is not quite accurate? What if it has some false positives? Then some of the placebo volunteers might test positive as well, and be a flag to take the positive results with a grain of salt.</p>\n", "score": 11 }, { "answer_id": 24082, "body": "<p>Antibodies only reflect one part of the immune response: the humoral immunity.</p>\n<p>There is another part of the immunity that can't be detected by dosing the antibodies: the <strong>cell-mediated immunity</strong>. It produces no antibodies. It only creates effector T-cells that can detect the presence of viruses (or some intra-cellular bacteria) inside body cells and destroy these cells or trigger apoptosis.</p>\n<p>This is one reason why checking the clinical outcomes of a vaccine is interesting. The results will be compared to antibody titers for interpretation.</p>\n", "score": 3 } ]

[ "covid-19", "placebo" ]

[ { "answer_id": 30865, "body": "<p>It turns out the answer to this is fairly simple, and but not terribly easy to find.</p>\n<p>In the 1800s a Belgian named <a href=\"https://en.wikipedia.org/wiki/Adolphe_Quetelet\" rel=\"nofollow noreferrer\">Adolphe Quetelet</a> (1796–1874) performed some statistics on the weights and heights of people in Europe and Britain (chiefly France and Britain) and published his seminal work, <em>Sur l'homme et le développement de ses facultés, ou Essai de physique sociale</em> (Treatise on Man and the Development of his Faculties, or Essays on Social Physics) in 1835. The relevant section for this can be <a href=\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/j.1550-8528.1994.tb00047.x\" rel=\"nofollow noreferrer\">found as a PDF</a> for free (I believe) at the Wiley Publishing journal <a href=\"https://onlinelibrary.wiley.com/doi/abs/10.1002/j.1550-8528.1994.tb00047.x\" rel=\"nofollow noreferrer\"><em>Obesity Research</em></a></p>\n<p>In this work, he examined the growth rates and dimensions of people throughout their lifetime, coming to the conclusion that after 30 people reached their maximum height and and after 40 for men and 50 for women, they reached their maximum weights.</p>\n<p>He has this to say about the developmental relationship between weight and height. Emphasis mine in all cases:</p>\n<blockquote>\n<p><strong>If man increased equally in all his dimensions, his weight at different ages would be as the cube of his height.</strong> Now, this is not what we really observe. The increase of weight is slower, except during the fist year after birth; then the proportion which we have just pointed out is pretty regularly observed. But after this period, and until near the age of puberty, the <strong>weight increases nearly as the square of the height</strong>. The development of the weight again becomes very rapid at the time of puberty, and almost stops at the twenty-fifth year. In general, we do not err much when we assume that, during development, the squares of the weight at different ages are as the fifth powers of the height; which naturally leads to this conclusion, in supposing the specific gravity constant, that the transverse growth of man is less than the vertical.</p>\n</blockquote>\n<p>He then goes on to state:</p>\n<blockquote>\n<p>However, if we compare two individuals who are fully developed and well-formed with each other, to ascertain the relations existing between the weight and stature, we shall find that the <strong>weight of developed per- sons, of different heights, is nearly as the square of the stature</strong>. Whence it naturally follows, that a transverse section, giving both the breadth and thickness, is just proportioned to the height of the individual.</p>\n</blockquote>\n<p>and continues after a table of statures and weights:</p>\n<blockquote>\n<p>Thus, the stature of men and women, fully developed and well-formed, varied in the proportion of five to six nearly: it is almost the same with the ratios of the weight to the stature of the two sexes: whence it naturally follows, <strong>as we have already said above, that the weight is in proportion to the square of the stature</strong>.</p>\n</blockquote>\n<p>and finally reaches a list of conclusions, with the 7th being:</p>\n<blockquote>\n<ol start=\"7\">\n<li>After the full development of individuals of both sexes, the weight is almost as the square of the stature. From the two preceding relations, we infer, that increase in height is greater than the transverse increase, including breadth and thickness.</li>\n</ol>\n</blockquote>\n<p>This work was then converted into the <a href=\"https://www.sciencedirect.com/science/article/pii/0021968172900276\" rel=\"nofollow noreferrer\">BMI measurement in 1974 by Ancel Keys in the Journal of Chronic Diseases</a>. In this article they state:</p>\n<blockquote>\n<p>In spite of the fact that it is easy to show that the body form does not remain constant with increasing length, the ponderal index, or the similar Rohrer index,W/H³, has been rather widely used....</p>\n</blockquote>\n<blockquote>\n<p>...In the present paper it will be shown, in confirmation of some recent conclusions of others, that in this respect the ratio W/H² is clearly better than the ponderal index. It is proposed that this ratio, W/H², be termed the body mass index.</p>\n</blockquote>\n", "score": 19 }, { "answer_id": 30866, "body": "<p>BMI isn't a &quot;real&quot; thing, it's an arbitrary measure meant to capture some aspect of &quot;overweightness&quot;. The exponent has traditionally been chosen as &quot;2&quot; because that roughly fit with data observed. In the <a href=\"https://www.sciencedirect.com/science/article/abs/pii/0021968172900276\" rel=\"noreferrer\">Keys et al 1972</a> paper that established BMI, they did try other exponents 1 and 3, but found 2 to be the best correlate of body fat.</p>\n<p>Cubed relationships between length and weight are only an approximation, and species vary quite a bit on how close they are to the &quot;cube rule&quot;. For a real-world application, I've come across this in the context of sport fishing, where it is easy to measure a fish's length but sometimes more difficult (you need a scale; the fish needs to hold still) and possibly harmful to the fish to weigh them; you can estimate an approximate weight from a species-specific formula, however. <a href=\"https://en.wikipedia.org/wiki/Standard_weight_in_fish\" rel=\"noreferrer\">Wikipedia</a> has a page on this with some examples for different species.</p>\n<p>For humans, we simply don't tend to follow a cubed relationship. A XX% change in height for humans is not associated with an equivalent XX% change in width or &quot;depth&quot;, it's associated with something a bit less.</p>\n<p>There have been some suggestions to use a different exponent than 2, though, because with the current formula, BMI tends to not track well with adiposity or health outcomes for the tallest or shortest individuals. A barrier to making this change is <a href=\"https://xkcd.com/927/\" rel=\"noreferrer\">agreeing on which one to use</a> and the inertia of a publication record on the old measure. Here are a few examples, though, where people have investigated whether a different exponent for height and/or weight would better index a healthy/unhealthy body composition (I'm sure there are many more; not all ultimately recommend against the current scaling):</p>\n<p>Foster, D., Karloff, H., &amp; Shirley, K. E. (2016). How well does the standard body mass index or variations with a different exponent predict human lifespan?. Obesity, 24(2), 469-475.</p>\n<p>Garn, S. M., Leonard, W. R., &amp; Hawthorne, V. M. (1986). Three limitations of the body mass index. The American journal of clinical nutrition, 44(6), 996-997.</p>\n<p>Tjeertes, E., Hoeks, S., van Vugt, J. L. A., Stolker, R. J., &amp; Hoofwijk, A. (2017). The new body mass index formula; not validated as a predictor of outcome in a large cohort study of patients undergoing general surgery. Clinical nutrition ESPEN, 22, 24-27.</p>\n<p>Xu, Y., Yan, W., &amp; Cheung, Y. B. (2015). Body shape indices and cardiometabolic risk in adolescents. Annals of Human Biology, 42(1), 70-75.</p>\n", "score": 12 }, { "answer_id": 30871, "body": "<p>While the answers of Bob and Bryan are perfectly valid, let me attempt to provide some intuition from a physics/statistics standpoint.</p>\n<p>Generally, when a quantity is proportional to some other quantity, raised to the n-th power, this <code>n</code> power is related to the effective number of degrees of freedom of the independent variable.</p>\n<p>For example, in the inverse <em>square</em> law, the number <em>2</em> arises from the fact that energy disperses in all space uniformly, and there is no degeneracy between any dimensions. The result is that consecutive wavefronts form spherical shells, and the surface area (of the sphere) is proportional to <code>r^2</code>.</p>\n<p>Conversely, humans can't expand in all 3 dimensions equally. The effective number of degrees of freedom for a human is about 2. One comes from the height, which is almost free to change. The other one comes from the combination of 'width' and 'depth'. These two are strongly degenerate - the technical term is that they <em>co-vary</em> almost completely, thus lowering the effective number of degrees of freedom.</p>\n<p>Note, the fact that width and depth are almost degenerate means that there is a linear relation between them. So that third dimension doesn't really play a role, because the human body is not free to grow in all space.</p>\n<p>How do we know that? That's empirical - it's just that the effective number of degrees of freedom for a human is closer to 2 than it is to 3. 3 is simply the upper bound when the object grows uniformly in all directions.</p>\n", "score": 2 } ]

[ "anatomy", "body-mass-index-bmi" ]

[ { "answer_id": 313, "body": "<h2>Background</h2>\n\n<p>Most kidney stones (~80%) are calcium stones, and the majority of those are primarily composed of calcium oxalate. Oxalate (C₂O₄²⁻) is a dianion that combines with divalent cations such as magnesium and calcium. The magnesium salt is much more soluble than the calcium salt. Because these cations compete for binding to oxalate, both lower magnesium levels and higher calcium levels will tend to cause precipitation (movement out of solution into crystalline form) of calcium oxalate. When this happens in the urine in large enough quantities, it can form “stones.”</p>\n\n<h2>Does diet matter?</h2>\n\n<p>As introduced by the OP, doctors have historically advised patients who have demonstrated a propensity toward calcium oxalate stone formation (or, more generically: kidney stones) to decrease dietary intake of calcium and oxalate.</p>\n\n<p><strong>Dietary calcium</strong> </p>\n\n<p>In 1993, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8441427\">a study published in the New England Journal of Medicine</a> dispelled the notion that a low calcium diet should be advised for these patients. They found the opposite association: higher calcium intake correlates with <em>reduced</em> stone formation (RR = 0.56; 95% CI 0.43 - 0.73). This somewhat counter-intuitive effect may be explained by the binding of calcium with oxalate in the gut, which tends to decrease oxalate absorption. The recommendation to decrease calcium intake, then, appears not to be valid. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=11784873\">Further studies</a> have refined this recommendation, and it is now generally said that a <strong>normal</strong> calcium intake is probably best.</p>\n\n<p><strong>Dietary oxalate</strong> </p>\n\n<p>Oxalate is found in <a href=\"http://my.clevelandclinic.org/services/urology-kidney/treatments-procedures/kidney-stones-oxalate-controlled-diet\">an odd assortment of foods</a>: beets, spinach, rhubarb, strawberries, nuts, chocolate, tea, wheat bran, and all dry beans (fresh, canned, or cooked), excluding lima and green beans. This has largely been a “seems like it should work” approach rather than data-driven. In fact, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=17538185\">large epidemiological studies</a> have not shown an association between oxalate intake and stone formation.</p>\n\n<p><strong>Other dietary associations</strong> </p>\n\n<p>The <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8441427\">NEJM study mentioned above</a> also looked at other correlations between stone formation and dietary components. Animal protein was directly correlated with increased risk of stones, whereas potassium and fluid intake were correlated with decreased risk.</p>\n\n<p><strong>A different approach</strong> </p>\n\n<p>The <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=24560157\">most recent interesting development</a> in this area that I’m aware of was published in the American Journal of Kidney Disease in 2014 and compared the DASH (Dietary Approaches to Stop Hypertension)-style diet with a low-oxalate diet for prevention of stones. Their reasoning is nicely summarized in the abstract:</p>\n\n<blockquote>\n <p>[M]ost people do not eat isolated nutrients, but meals consisting of a variety of foods with complex combinations of nutrients. A more rational approach to nephrolithiasis prevention would be to base dietary advice on the cumulative effects of foods and different dietary patterns rather than single nutrients.</p>\n</blockquote>\n\n<p>The DASH diet was, as its name suggests, developed as a tool to mitigate hypertension, but it has been used as a sort of paradigm “healthy diet” in trials of a variety of interventions. It is, as described in the paper above, high in fruits and vegetables, moderate in low-fat dairy products, and low in animal protein. The high fruit and nut content may be expected to increase urinary oxalate, but these foods also tend to be high in magnesium and citrate, both of which are inhibitors of calcium stone formation.</p>\n\n<p>The authors collected 24-hour urine samples in participants with a known history of stones and randomized them to a DASH diet vs a low-oxalate diet. They found that urinary supersaturation of calcium oxalate (a measure of tendency to form calcium oxalate stones) was decreased in the DASH group compared to the low-oxalate group. This occurred despite a trend toward <em>increased</em> oxalate excretion in that group. The authors posit that this may have been due to the increased urinary pH and concentrations of citrate, magnesium, and potassium, all of which tend to decrease stone formation.</p>\n\n<p><strong>Conclusion</strong></p>\n\n<p>There are not solid data supporting a low oxalate diet for stone prevention. Other dietary factors that are probably helpful include: normal calcium intake; high intake of fluid, magnesium, and potassium; low animal protein.</p>\n\n<hr>\n\n<p><strong>References</strong></p>\n\n<p>_{\nBorghi L., Schianchi T., Meschi T., et al: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=11784873\"><em>Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria.</em></a> N Engl J Med 2002(346):77-84.\n}</p>\n\n<p>_{\nCoe FL, Evan A, Worcester E. (2005). <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=16200192\"><em>Kidney stone disease.</em></a> J Clin Invest. 115(10):2598–2608.\n}</p>\n\n<p>_{\nCurhan G.C., Willett W.C., Rimm E.B., and Stampfer M.J.: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8441427\"><em>A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones.</em></a> N Engl J Med 1993(328):833-838.\n} </p>\n\n<p>_{\nNoori N, Honarkar E1, Goldfarb DS2, Kalantar-Zadeh K3, Taheri M1, Shakhssalim N1, Parvin M1, Basiri A. <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=24560157\"><em>Urinary lithogenic risk profile in recurrent stone formers with hyperoxaluria: a randomized controlled trial comparing DASH (Dietary Approaches to Stop Hypertension)-style and low-oxalate diets.</em></a>\nAm J Kidney Dis.2014; 63(3):456-63.\n} </p>\n\n<p>_{\nTaylor E.N., and Curhan G.C.: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=17538185\"><em>Oxalate intake and the risk for nephrolithiasis</em></a>. J Am Soc Nephrol 2007(18):2198-2204.\n}</p>\n", "score": 11 }, { "answer_id": 327, "body": "<p>I am not a health professional, but I did some research on exactly your question because my friend, who is quite young, has calcium oxalate kidney stones. Most of my citations are not directly from academic journals, but from websites of well known medical centers (see below). </p>\n\n<p>Few things that I learned (in addition to Susan's answer):</p>\n\n<p>-drinking enough fluids seems to be the most important thing for prevention</p>\n\n<p>-\"Sodium, often from salt, causes the kidneys to excrete more calcium into the urine. High concentrations of calcium in the urine combine with oxalate and phosphorus to form stones. Reducing sodium intake is preferred to reducing calcium intake.\"</p>\n\n<p>-reduce oxalate intake. University of Pittsburgh Medical School has comprehensive information about this. </p>\n\n<p>I know this doesn't answer to what extent calcium oxalate stones can be prevented with diet, but those things appear to contribute to it.</p>\n\n<p>1) <a href=\"http://www.mayoclinic.org/diseases-conditions/kidney-stones/basics/definition/con-20024829\" rel=\"noreferrer\">Mayo Clinic</a></p>\n\n<p>2) <a href=\"http://kidney.niddk.nih.gov/Kudiseases/pubs/kidneystonediet/index.aspx\" rel=\"noreferrer\">NIH, National Kidney and Urologic Diseases</a></p>\n\n<p>3) <a href=\"http://www.upmc.com/patients-visitors/education/nutrition/pages/low-oxalate-diet.aspx\" rel=\"noreferrer\">Univ. of Pittsburgh Medical School</a></p>\n", "score": 5 } ]

[ "renal", "urology", "kidney-stones" ]

[ { "answer_id": 112, "body": "<h3>What is Aloe vera?</h3>\n\n<p><a href=\"http://en.wikipedia.org/wiki/Aloe_vera\" rel=\"nofollow\">Aloe vera</a> is the common name of one particular species of the genus Aloe (member of the Xanthorrhoeaceae family). There are over 420 different plant species and the most commonly used in consumer products. Most commonly used is Aloe barbadensis, Aloe barbadensis (Mill.) or (Miller) or Aloe vera (L.) Burm. f. (scientific name).</p>\n\n<h3>Processing</h3>\n\n<p>The primary component of the plant used in most products is the leaf, which can be processed in two ways to make aloe vera juice, powder or concentrate.</p>\n\n<p>The other substance found within the leaf that has been used in commerce, primarily as an OTC laxative drug, is the aloe latex. </p>\n\n<p>For oral consumption Aloe vera needs to be carefully filtered by different processing procedures:</p>\n\n<ul>\n<li><p>Aloe vera leaf juice</p>\n\n<p>A charcoal filtration process which decolorize and remove some of the components (including <a href=\"http://en.wikipedia.org/wiki/Anthraquinone\" rel=\"nofollow\">anthraquinone</a> which acts as <a href=\"http://en.wikipedia.org/wiki/Laxative\" rel=\"nofollow\">laxative</a>) as some studies shown to be carcinogenic on rats, but not on mice (see <a href=\"http://en.wikipedia.org/wiki/Aloe_vera#Toxicity\" rel=\"nofollow\">Toxicity</a>). NTP did not conduct studies of the Aloe vera gel (decolorized whole leaf extracts).</p>\n\n<blockquote>\n <p>Aloe vera leaf juice is made by taking entire aloe vera leaves and grinding them up via some type of maceration. Typically some enzymatic treatment is used (such as cellulase) to break down the rind and heavier-weight materials, and then the resulting slurry is filtered, usually with charcoal filtration, to remove any other unwanted materials such as the aloe latex (yellow, bitter tasting exudate that is a powerful laxative). The remainder is aloe vera leaf juice.</p>\n</blockquote></li>\n<li><p>Aloe vera inner leaf juice</p>\n\n<blockquote>\n <p>Aloe vera inner leaf juice is made by removing the rind prior to processing, either by machine or by hand, and then rinsing away the aloe latex. The remaining, gelatinous inner-leaf material is then ground/crushed into aloe vera inner leaf juice.</p>\n</blockquote></li>\n</ul>\n\n<p>In some other countries Aloe vera juice is produced using the patented <a href=\"http://www.aloecorp.com/production\" rel=\"nofollow\">TTS (Time, Temperature, Sanitation)</a> method.</p>\n\n<p>Once Aloe vera gel is filtered out for consumption, then it's considered safe, because without filtration it can be harmful causing potential toxicity when swallowed. </p>\n\n<p>Aloe vera that contains <a href=\"http://en.wikipedia.org/wiki/Aloin\" rel=\"nofollow\">aloin</a> (however it's not for sure) in excess amounts may induce side effects, but there is very little data about what levels of aloin are in most liquid products (according to one research, it's less than 1ppm), however in solid/semi-solid products it could be 10-100 times higher. If aloin is the cause of the tumors in rats, then the lower the concentration of aloin, then it's less harmful. However more research is needed to answer these questions.</p>\n\n<h3>Is Aloe vera regulated?</h3>\n\n<p>In US Aloe vera is a dietary supplement and it's not regulated drug, so there is no guarantee of strength, purity, or safety of these products. Currently Aloe vera is approved by FDA as a food addictive for flavor.</p>\n\n<p>In the UK, European Union, China, and Korea content and purity of Aloe is regulated by <a href=\"http://www.iasc.org/\" rel=\"nofollow\">IASC</a> (International Aloe Science Council Seal of Approval) which established standards to define what is (and what is not) \"aloe vera\" in finished products. The IASC standard states that only products containing acemannan, or the beta 1-4 acetylated glucomannans, can be accurately labeled as aloe vera. Acemannan is a naturally occurring polysaccharide that is present in aloe vera and is used as an identifier of the botanical by analytical means. Products that do not contain acemannan are not considered to be true aloe vera based on this standard.</p>\n\n<h3>How can I tell if a product truly contains Aloe vera?</h3>\n\n<p>In countries where Aloe vera is regulated, you should check the label for seal-based certification (see: <a href=\"http://www.iasc.org/pdfs/10_0405_IASC_Labeling_Guidance_Definitions.pdf\" rel=\"nofollow\">labeling guidance</a>). You may also check the <a href=\"http://www.iasc.org/complete.html\" rel=\"nofollow\">certified products list on IASC website</a>. Also make sure that <a href=\"http://en.wikipedia.org/wiki/Aloin\" rel=\"nofollow\">Aloin</a> content has been removed.</p>\n\n<h3>Health benefits</h3>\n\n<p>Potential health benefits of drinking Aloe vera juice includes:</p>\n\n<ul>\n<li><p>support the digestive system and relieve constipation,</p>\n\n<p>For example mixing Aloe with different oils and lemon juice can reach the entire gastrointestinal track to the colon. Oil blocks absorption of two other ingredients too soon so lemon juice can dissolve deposits in GI tract, gall bladder and pancreatic ducts, and after absorption, in the kidneys. Aloe can also heal infection such as erosions in the lining of the digestive track. ^{(<a href=\"http://merlin.pl/Zdrowie-na-wlasne-zyczenie-1-Oczyszczenie_Jozef-Slonecki/browse/product/1,475683.html\" rel=\"nofollow\">book source</a>)}</p></li>\n<li><p>enhance natural immunity,</p></li>\n<li>improve skin condition and health,</li>\n<li><p>naturally contains <a href=\"http://en.wikipedia.org/wiki/Polysaccharide\" rel=\"nofollow\">polysaccharides</a> which provide many benefits to the body such as:</p>\n\n<ul>\n<li>healthy blood sugar levels,</li>\n<li>liver function,</li>\n<li>intestinal health: helping to reduce colon cancer,</li>\n<li>reduce serum cholesterol levels,</li>\n<li>exhibit immunomodulatory, antitumor, antithrombotic, anticoagulant, anti-mutagenic, anti-inflammatory, antimicrobial, and antiviral activities including anti-HIV infection, herpes, and hepatitis viruses^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22909979\" rel=\"nofollow\">study</a>},</li>\n</ul></li>\n<li>some other benefits include: hair loss, Helicobacter, atherosclerosis, sensitization, overweight, mycosis, neuroses, sepsis, cancer.</li>\n</ul>\n\n<p>Aloe vera gel is also used as traditional medicine (especially in Asia) for multipurpose skin treatment.</p>\n\n<p>However relatively few studies about possible benefits of Aloe gel taken internally have been conducted.</p>\n\n<blockquote>\n <p>If you've any concerns or medical conditions, you should speak with your physician before altering any existing treatments.</p>\n</blockquote>\n\n<hr>\n\n<p>See:</p>\n\n<ul>\n<li><a href=\"https://www.niehs.nih.gov/health/materials/aloe_vera_508.pdf\" rel=\"nofollow\">National Toxicology Program - Aloe Vera (PDF)</a></li>\n<li><a href=\"http://www.iasc.org/faq.html\" rel=\"nofollow\">IASC Aloe Vera FAQ</a></li>\n</ul>\n", "score": 7 }, { "answer_id": 19577, "body": "<p><strong>Possible health benefits</strong></p>\n\n<p>Aloe vera by mouth is possibly effective for:</p>\n\n<ul>\n<li>relieving constipation</li>\n<li>reducing blood sugar and HbA1c in people with type 2 diabetes</li>\n<li>healing peptic ulcers (inconsistent evidence)</li>\n</ul>\n\n<p><strong>Possible side effects</strong></p>\n\n<p>Aloe vera latex by mouth may:</p>\n\n<ul>\n<li>trigger diarrhea</li>\n<li>increase the risk of cancer (insufficient evidence)</li>\n</ul>\n\n<p>Sources:</p>\n\n<ul>\n<li><a href=\"https://www.webmd.com/vitamins/ai/ingredientmono-607/aloe\" rel=\"nofollow noreferrer\">Natural Medicines Comprehensive Database</a></li>\n<li><a href=\"https://www.mayoclinic.org/drugs-supplements-aloe/art-20362267\" rel=\"nofollow noreferrer\">Mayo Clinic</a></li>\n<li><a href=\"https://nccih.nih.gov/health/aloevera\" rel=\"nofollow noreferrer\">National Center for Complementary and Integrative Health</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/books/NBK92765/\" rel=\"nofollow noreferrer\">Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition</a></li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4557234/\" rel=\"nofollow noreferrer\">Pharmacognosy Review</a></li>\n</ul>\n", "score": 2 } ]

[ "nutrition", "cancer", "natural-remedy", "supplement" ]

[ { "answer_id": 238, "body": "<p>There is some research that has been done on this, as well as some more anecdotal/lifestyle based evidence.</p>\n\n<p>There is a study done in 1914, published in the <a href=\"http://books.google.com/books?hl=en&amp;lr=&amp;id=GPYEAAAAYAAJ&amp;oi=fnd&amp;pg=PA114&amp;dq=eating%20sitting%20position%20standing%20reclining&amp;ots=dp30D7yrn_&amp;sig=BRynH9whTS71gD5KAij8alhwfVs#v=onepage&amp;q&amp;f=false\">American Journal of Physiology</a>, where they examined the carbon dioxide tension of the blood after eating. CO2 tension is a byproduct of food metabolism, and in high amounts can cause dyspnea, acidosis and possibly altered consciousness. The findings showed that standing, then sitting, then lying each produced higher CO2 tension than the previous position. Trendelenburg (Lying with head lower than legs) produced less than lying, approximating the sitting position. Sitting erect also had lower tension than sitting reclined.</p>\n\n<p>More anecdotally, <a href=\"http://www.thehealthsite.com/diseases-conditions/why-you-should-sit-on-the-floor-while-eating/\">this website posting</a> looks at the traditional Indian position of sitting on the floor while eating, which promotes a more erect sitting stance than sitting on a chair/couch or reclining while eating. While not backed up with studies, it also claims that the vagus nerve response is enhanced in this position, resulting in quicker time to satiety (You eat less as a result). Many Middle Eastern cultures eat this way, as do more traditional Asian homes where the seats are merely cushions on a floor around a short table. There are many other benefits listed in the article, but for brevity and provability I won't cite them all here.</p>\n\n<p>I also ran across references (But was unable to find the actual study) to a 2007 study involving women published in the Journal of the Academy of Nutrition and Dietetics, that found people standing up tended to pay less attention to the food, and as a result ate faster and more. It's fairly well established that the vagus nerve response to feel full is in the neighborhood of 20 minutes to take effect, so if you eat slower (as promoted by sitting down) you will also tend to eat less overall. It's also been shown that eating without distractions such as television and reading promotes lower consumption overall.</p>\n\n<p>So in effect, it appears that sitting in an erect position is possibly the best happy medium, and if possible, eating without distractions to be able to concentrate on the food. Especially if you suffer from acid upsets or other related ailments, the more erect you are the more you may ease your symptoms.</p>\n", "score": 12 }, { "answer_id": 400, "body": "<p>When we sit we eat slower and digest the food more properly, because we're more calm. When standing we do things faster, hence we are less focused what we eat and not chew food properly by adding saliva and its digestive enzymes which helps to digest and metabolise your food more efficiently. More stress could also have negative effect on your esophagus. However studies from <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8194499\" rel=\"noreferrer\">1994</a> and <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19160046\" rel=\"noreferrer\">2010</a> found no relationship with the frequency of indigestion.</p>\n\n<p>People with <a href=\"http://en.wikipedia.org/wiki/Gastroesophageal_reflux_disease\" rel=\"noreferrer\">reflux</a> symptoms are advised to remain upright during and after eating which can keep the acid down in the stomach where it belongs (so doesn't comes back up into the oesophagus).</p>\n\n<p>People who have weakness of the muscles around the mouth, they should seek advice from a speech and language therapist concerning the best sitting position for safe swallowing.^{<a href=\"http://www.nhs.uk/ipgmedia/national/multiple%20sclerosis%20trust/assets/areyousittingcomfortably.pdf\" rel=\"noreferrer\">(NHS)</a>}</p>\n\n<p>So as long as you're healthy and chew food properly in non-stressful environment, there doesn’t seem to be any harm in what position do you eat and how fast.</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://www.bbc.com/future/story/20130502-is-eating-on-the-run-bad-for-you\" rel=\"noreferrer\">Does eating standing up give you indigestion?</a> at BBC</li>\n</ul>\n", "score": 7 } ]

[ "posture", "nutrition" ]

[ { "answer_id": 5106, "body": "<p><strong>Please see the following society guidelines first:</strong></p>\n\n<p><a href=\"http://circ.ahajournals.org/content/114/10/1088.full.pdf\" rel=\"nofollow\">The 2006 American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) guidelines:</a></p>\n\n<blockquote>\n <p>●There is evidence and/or general agreement supporting RF ablation in\n patients with symptomatic idiopathic VT that is drug-refractory, or in\n such patients who are intolerant of drugs or do not desire long-term\n drug therapy.</p>\n \n <p>●The weight of evidence and/or opinion supports the use of beta\n blockers and/or calcium channel blockers for the treatment of\n symptomatic idiopathic VT.</p>\n \n <p>●The weight of evidence and/or opinion supports the use of class IC\n antiarrhythmic drugs as an alternative to or in combination with beta\n blockers and/or calcium channel blockers for the treatment of\n symptomatic idiopathic VT that arises from the RVOT. Subsequently, the\n 2009 European Heart Rhythm Association/Heart Rhythm Society (EHRA/HRS)\n expert consensus statement recommended catheter ablation in the\n following patients with idiopathic VT and without structural heart\n disease [86]:</p>\n \n <ol>\n <li>Severely symptomatic patients with monomorphic VT. </li>\n <li>Monomorphic VT in patients in whom antiarrhythmic drugs are not\n effective, not tolerated, or not desired. </li>\n <li>Patients with recurrent sustained polymorphic VT and VF (electrical storm) that is refractory to antiarrhythmic therapy when\n there is a suspected trigger that can be targeted for ablation</li>\n </ol>\n</blockquote>\n\n<p>Medical (non-interventional/ablative) management is what is recommended-- especially verapamil or a beta blocker as they are easy to take (pills), and have a pretty nice side effect profile. You can easily find the adverse effects online but they would primarily have to do with heart rate and blood pressure and those are easily monitored.</p>\n\n<p>Ablation is a procedure a cardiology electrophysiologist would do in the \"cath lab.\" This would be in conjunction with an \"EP Study\" which is an electrophysiology study of the heart to try to find the culprit location that starts the arrythmia. Ablation is sometimes used (see above) in medical-refractory cases.</p>\n\n<p>You can consider amiodarone or other antiarrythmics but they have more side effects. Amiodarone is known to have a very long half life and a long list of side effects which require chronic monitoring (thyroid issues, lung issues, etc.) which is why they are not really first line usually in these cases though can be added on to the first line agents mentioned above.</p>\n\n<p><strong><em>As an aside:</em></strong></p>\n\n<ul>\n<li>Cardioversion, per the roots of the word, is changing/turning the direction of the heart--> You can think of this as changing the rhythm.</li>\n<li>Defibrillation is a <strong>subset</strong> of cardioversion where it is done without any synchronization in cases of ventricular <strong>fibrillation</strong>. Defibrillation = Asynchronous cardioversion</li>\n<li>Many medical providers use the term cardioversion in cases of only supraventricular or ventricular <strong>tachycardia</strong> (in this case usually synchronous)\n<strong>- Cardioversion, as it is changing the rhythm of the heart (electrical or chemical), includes defibrillation but usually is used as a term specific to supraventricular or ventricular tachycardia as defibrillation is more specific when cardioversion is used in ventricular fibrillation.</strong></li>\n</ul>\n", "score": 5 } ]

[ "cardiology", "research", "treatment-options" ]

[ { "answer_id": 497, "body": "<p>There are some downsides to eating whole-grain rice, primarily that brown rice has <a href=\"http://pubs.acs.org/doi/abs/10.1021/es702212p\">consistently higher levels of inorganic arsenic in it</a> <a href=\"http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm\">including rice found in the U.S.</a>. The EPA's maximum contaminant level for arsenic is <a href=\"http://www.epa.gov/teach/chem_summ/Arsenic_summary.pdf\">10 micrograms/L in water</a>, and there's <a href=\"http://www.sciencedirect.com/science/article/pii/S0269749108001759\">some suggestion</a> that the level of arsenic contamination in brown rice could be pushing up against that threshold.</p>\n\n<p>As far as I'm aware though, there haven't been any definitive studies on health outcomes for people consuming brown vs. white rice.</p>\n", "score": 7 }, { "answer_id": 554, "body": "<h3>Nutrients</h3>\n\n<p>A detailed analysis of nutrient content of rice suggests that the nutrition value of rice varies based on a number of factors (depends on the strain of rice and its color). Comparative nutrition studies on varieties of rice suggest that highly colored rice strains have more antioxidant properties^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/19138081\" rel=\"noreferrer\">2009</a>}.</p>\n\n<p>Red or black rice consumption was found (in mammals) to reduce the progression of atherosclerotic plaque development, however white rice consumption offered no similar benefits which can suggest may be due in in a lack of antioxidants found in other varieties of rice^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/11340093\" rel=\"noreferrer\">2001</a>}.</p>\n\n<p>In comparison to whole grain, the <a href=\"https://en.wikipedia.org/wiki/White_rice\" rel=\"noreferrer\">white rice</a> is milled rice that has had its husk, bran, and germ removed.</p>\n\n<p>For full comparison table of nutrient content, please check: <a href=\"https://en.wikipedia.org/wiki/Rice#Comparison_of_rice_to_other_major_staple_foods\" rel=\"noreferrer\">Comparison of rice to other major staple foods at Wikipedia</a>.</p>\n\n<h3>Inorganic Arsenic in Rice</h3>\n\n<p>The downside of eating different type of rice can be amount of arsenic (naturally occurring element in air, soil, water and foods). It has been found that rice is susceptible to accumulation of arsenic from soil^{<a href=\"http://www.bostonglobe.com/lifestyle/health-wellness/2011/12/08/you-need-worry-about-arsenic-rice/KGsMAwBoe0NnYupiC68v9N/story.html\" rel=\"noreferrer\">Boston Globe</a>}.</p>\n\n<blockquote>\n <p>Arsenic exposure during pregnancy is a public health concern due to potential health risks to the fetus^{<a href=\"http://medicalxpress.com/news/2011-12-rice-source-arsenic-exposure.html\" rel=\"noreferrer\">Medical Xpress</a>}.</p>\n</blockquote>\n\n<p>Summary table of Inorganic Arsenic in Rice and Rice Products:</p>\n\n<p><img src=\"https://i.stack.imgur.com/iFifr.png\" alt=\"FDA - Inorganic Arsenic in Rice and Rice Products\"></p>\n\n<p>^{Source: <a href=\"http://www.fda.gov/downloads/Food/FoodborneIllnessContaminants/Metals/UCM352467.pdf\" rel=\"noreferrer\">Inorganic Arsenic in Rice and Rice Products</a> and <a href=\"http://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm319916.htm\" rel=\"noreferrer\">Full Analytical Results</a> at FDA}</p>\n\n<p>The FDA, the agency responsible for overseeing the safety of our food supply, has been monitoring arsenic content for more than 20 years, however not indicated that the average daily intake of arsenic is unsafe and not established standards the acceptable limit standards of arsenic in food.</p>\n\n<p>^{\nRead more:</p>\n\n<ul>\n<li><a href=\"https://en.wikipedia.org/wiki/Arsenic_poisoning#Food\" rel=\"noreferrer\">Arsenic poisoning: Food</a> &amp; <a href=\"https://en.wikipedia.org/wiki/Rice#Arsenic_concerns\" rel=\"noreferrer\">Rice: Arsenic concerns</a> at Wikipedia</li>\n<li><a href=\"http://medicalxpress.com/news/2011-12-rice-source-arsenic-exposure.html\" rel=\"noreferrer\">Rice as a source of arsenic exposure</a> at Medical Xpress</li>\n<li><a href=\"http://www.speciation.net/News/Surprisingly-high-concentrations-of-toxic-arsenic-species-found-in-US-rice-;~/2005/08/03/1561.html\" rel=\"noreferrer\">Surprisingly high concentrations of toxic arsenic species found in U.S. rice</a> at Evisa</li>\n<li><a href=\"http://www.speciation.net/News/China-Inorganic-Arsenic-in-Rice--An-Underestimated-Health-Threat--;~/2010/05/19/5027.html\" rel=\"noreferrer\">China: Inorganic Arsenic in Rice - An Underestimated Health Threat?</a> at Evisa</li>\n<li><a href=\"http://www.epa.gov/airtoxics/hlthef/arsenic.html\" rel=\"noreferrer\">Arsenic Compounds</a> at EPA</li>\n<li><a href=\"http://www.epa.gov/ordntrnt/ORD/priorities/docs/Arsenic_in_Food_FS.pdf\" rel=\"noreferrer\">EPA Computer Models Predict Exposures to Arsenic that Echo Reality (PDF)</a></li>\n<li><a href=\"ftp://ftp.fao.org/codex/meetings/cccf/cccf5/cf05_10e.pdf\" rel=\"noreferrer\">\"Discussion Paper on Arsenic in Rice\" (2011) (PDF)</a>\n}</li>\n<li>Book: <a href=\"https://en.wikipedia.org/wiki/Special:BookSources/9789400729469\" rel=\"noreferrer\">Andrew A. Meharg and Fang-Jie Zhao, Arsenic &amp; Rice</a></li>\n</ul>\n", "score": 5 } ]

[ "nutrition" ]

[ { "answer_id": 443, "body": "<p><a href=\"http://en.wikipedia.org/wiki/Passive_smoking\" rel=\"nofollow noreferrer\">Passive (or secondhand) smoking</a> can increase your risk of cancer and other health problems. Inhaled smoke is a mixture of smoke from the burning end of a cigarette or cigar and the smoke exhaled from the lungs of smokers. It is harmful and may cause a wide range of adverse health effects, particularly harmful for children.</p>\n\n<p>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\n<p>Children who breathe in secondhand smoke have an increased risk of:</p>\n\n<ul>\n<li>cot death (sudden infant death syndrome, or SIDS) – this is twice as likely in babies whose mothers smoke^{<a href=\"http://en.wikipedia.org/wiki/Sudden_infant_death_syndrome\" rel=\"nofollow noreferrer\">wiki</a>, <a href=\"http://www.nhs.uk/Conditions/Sudden-infant-death-syndrome/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">NHS</a>},</li>\n<li>lung infections^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/10333302\" rel=\"nofollow noreferrer\">1999</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12818898\" rel=\"nofollow noreferrer\">2003</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/14586058\" rel=\"nofollow noreferrer\">2003</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15060193\" rel=\"nofollow noreferrer\">2004</a>},</li>\n<li>impaired respiratory function and slowed lung growth^{<a href=\"http://www.cdc.gov/nccdphp/publications/factsheets/prevention/pdf/smoking.pdf\" rel=\"nofollow noreferrer\">2007</a>},</li>\n<li>developing asthma – smoking can also trigger asthma attacks in children who already have the condition^{<a href=\"http://www.nhs.uk/conditions/asthma/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">NHS</a>},</li>\n<li>allergies,</li>\n<li>Crohn's disease^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17206676\" rel=\"nofollow noreferrer\">2007</a>},</li>\n<li>serious respiratory (breathing) conditions such as <a href=\"http://www.nhs.uk/conditions/bronchitis/pages/introduction.aspx\" rel=\"nofollow noreferrer\">bronchitis</a> and <a href=\"http://www.nhs.uk/conditions/Pneumonia/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">pneumonia</a> – younger children are also much more likely to be admitted to hospital for a serious respiratory infection,</li>\n<li><a href=\"http://www.nhs.uk/conditions/meningitis/pages/introduction.aspx\" rel=\"nofollow noreferrer\">meningitis</a>,</li>\n<li><a href=\"http://www.nhs.uk/conditions/cough/pages/introduction.aspx\" rel=\"nofollow noreferrer\">coughs</a> and <a href=\"http://www.nhs.uk/conditions/cold-common/pages/introduction.aspx\" rel=\"nofollow noreferrer\">colds</a>,</li>\n<li><a href=\"http://www.nhs.uk/Conditions/Otitis-media/Pages/Introduction.aspx\" rel=\"nofollow noreferrer\">a middle ear infection</a> (<a href=\"http://en.wikipedia.org/wiki/Otitis_media\" rel=\"nofollow noreferrer\">otitis media</a>), which can cause <a href=\"http://www.nhs.uk/conditions/hearing-impairment/pages/introduction.aspx\" rel=\"nofollow noreferrer\">hearing loss</a>^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18484936\" rel=\"nofollow noreferrer\">2008</a>},</li>\n<li>learning difficulties, developmental delays, and neurobehavioral effects^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/8619139\" rel=\"nofollow noreferrer\">1996</a>, <a href=\"http://web.archive.org/web/20090327101820/http://www.iceh.org/pdfs/LDDI/LDDIStatement.pdf\" rel=\"nofollow noreferrer\">2008</a>},</li>\n<li>an increase in tooth decay^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/18672230\" rel=\"nofollow noreferrer\">2008</a>}.</li>\n</ul>\n\n<p>^{Source: <a href=\"http://www.nhs.uk/chq/pages/2289.aspx?categoryid=53\" rel=\"nofollow noreferrer\">Is passive smoking harmful?</a> at NHS and <a href=\"http://en.wikipedia.org/wiki/Passive_smoking\" rel=\"nofollow noreferrer\">Wikipedia</a>}</p>\n\n<p>For adults this includes:</p>\n\n<ul>\n<li>cancer,\n\n<ul>\n<li>lung cancer,</li>\n<li>breast cancer,</li>\n<li>brain tumor,</li>\n</ul></li>\n<li>risk of ear infections,</li>\n<li>cardiovascular disease:\n\n<ul>\n<li>risk of heart disease,</li>\n<li>reduced heart rate variability,</li>\n<li>higher heart rate,</li>\n<li>increased risk of atherosclerosis^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19302752\" rel=\"nofollow noreferrer\">2009</a>},</li>\n</ul></li>\n<li>respiratory disease such as lung problems and risk of asthma,</li>\n<li>cognitive impairment and dementia,</li>\n<li>during pregnancy can cause:\n\n<ul>\n<li>low birth weight,</li>\n<li>premature birth,</li>\n<li>damage to children's carotid arteries at birth and at age 5^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/22201150\" rel=\"nofollow noreferrer\">2012</a>},</li>\n<li>higher risks of delivering a child with congenital abnormalities, longer lengths, smaller head circumferences, and low birth weight^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/20085532\" rel=\"nofollow noreferrer\">2010</a>},</li>\n</ul></li>\n<li>skin disorders (such as Atopic dermatitis)^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3062947/\" rel=\"nofollow noreferrer\">2011</a>},</li>\n<li>worsening of asthma, allergies, and other conditions^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15137524\" rel=\"nofollow noreferrer\">2004</a>},</li>\n<li>increased risk of death^{<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1984876\" rel=\"nofollow noreferrer\">1991</a>, <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/1638735\" rel=\"nofollow noreferrer\">1992</a>}.</li>\n</ul>\n\n<p>In 2003, IARC and WHO reviewed all significant published evidence related to tobacco smoking and cancer and concluded:</p>\n\n<blockquote>\n <p>These meta-analyses show that there is a statistically significant and consistent association between lung cancer risk in spouses of smokers and exposure to second-hand tobacco smoke from the spouse who smokes. The excess risk is of the order of 20% for women and 30% for men and remains after controlling for some potential sources of bias and confounding.</p>\n</blockquote>\n\n<p>Other studies confirmed these findings, such as <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/17267733\" rel=\"nofollow noreferrer\">study from 2007</a> by American Journal of Public Health which claim^{<a href=\"http://monographs.iarc.fr/ENG/Monographs/vol83/index.php\" rel=\"nofollow noreferrer\">2004</a>, <a href=\"http://monographs.iarc.fr/ENG/Monographs/vol83/mono83.pdf\" rel=\"nofollow noreferrer\">PDF</a>}:</p>\n\n<blockquote>\n <p>A strong relationship was observed between lung cancer and duration of exposure to environmental tobacco smoke. The findings provide the strongest evidence to date that exposure to environmental tobacco smoke in the workplace is associated with <strong>an increased risk of lung cancer</strong>.</p>\n</blockquote>\n\n<p><img src=\"https://i.stack.imgur.com/vVC2m.png\" alt=\"Risks from Smoking\"></p>\n\n<p>^{Image credits: <a href=\"http://commons.wikimedia.org/wiki/File:Risks_form_smoking-smoking_can_damage_every_part_of_the_body.png\" rel=\"nofollow noreferrer\">CDC</a>}</p>\n\n<p>See also:</p>\n\n<ul>\n<li><a href=\"http://en.wikipedia.org/wiki/Passive_smoking#Effects\" rel=\"nofollow noreferrer\">Passive smoking: Effects</a> at Wikipedia</li>\n<li><a href=\"https://health.stackexchange.com/questions/364/smoking-during-pregnancy\">Health effects of smoking during pregnancy</a></li>\n</ul>\n", "score": 7 }, { "answer_id": 420, "body": "<p>According to <a href=\"http://www.betterhealth.vic.gov.au/bhcv2/bhcsite.nsf/pages/bhc_aboutus?open\" rel=\"noreferrer\">The Better Health Channel</a> (independant of any business, funded by the State Government of Victoria, Australia), passive smokers are exposed to many health risks that include long-term effects.</p>\n<p>To make it short:</p>\n<blockquote>\n<p>Second-hand smoke is a danger to everyone, but children, pregnant women and the partners of people who smoke are most vulnerable. Passive smoking increases the risk of sudden infant death syndrome (SIDS or cot death), middle ear disease, asthma, respiratory illnesses, lung cancer and coronary heart disease.</p>\n<p>People who have never smoked who live with people who do smoke are at increased risk of a range of tobacco-related diseases, including lung cancer, heart disease and stroke.</p>\n</blockquote>\n<p>The full explanation (and list of risks depending on subjects) is available <a href=\"http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/passive_smoking\" rel=\"noreferrer\">here on the BHC website</a>.</p>\n", "score": 5 } ]

[ "smoking", "pulmonology" ]

[ { "answer_id": 481, "body": "<p>Yes, you can get a full face mask and then it wont matter if you are breathing through your mouth or not. I would contact your medical equipment provider again and see what they have in options for full face masks. Personally I use Quattro full face mask and have no issues with it.</p>\n\n<p>You can look <a href=\"http://www.cpap.com/cpap-masks/full-face-cpap-mask.php\">here</a> for an idea of what masks are out there to chose from.</p>\n\n<p>You can also check <a href=\"http://www.cpaptalk.com/CPAP-Sleep-Apnea-Forum.html\">here</a> for more information and a group that will be able to answer questions about a wide variety of masks and they might have a solution to help you with your current problem without having to switch mask styles. </p>\n", "score": 6 } ]

[ "sleep-apnea" ]

[ { "answer_id": 862, "body": "<p>We should clarify some terms here. Scoliosis <strong>is</strong> a deformation, but Lordosis and kyphosis are not. The latter two are normal structural parts of human spine. </p>\n\n<p>Back to your question, we don´t know.</p>\n\n<p>Altogether the pathogenesis of scoliosis is poorly established and mostly unknown. </p>\n\n<p>In adolescent scoliosis, it seems that presence of scoliosis is mostly associated to genetic factors <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3293085/pdf/1748-7161-6-26.pdf\" rel=\"nofollow\">(Burwell et al.)</a>. 97% of patients presenting with adolescent scoliosis have a positive familial history <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566252/pdf/11832_2012_Article_458.pdf\" rel=\"nofollow\">(Dayer et al.)</a>.</p>\n\n<p>A recent review article sums the current knowledge of the pathogenesis of scoliosis (Dayer et al.). The interactions in molecular level, brain, vestibular system and in structural biomechanics are extremely complex and authors conclude quite fairly: \"Many factors are potentially involved in the pathogenesis of adolescent scoliosis, leading some authors to formulate a complex collective model from these different concepts.\"</p>\n\n<p>As so there is not currently any explicit evidence which would state the harms of any static risk factors (sleeping) affecting to development of scoliosis. Partly due to this vagueness I think the debate regarding risk of scoliosis is prone to bias and emotional \"truths\" and wisdoms.</p>\n\n<p>In a recent population level study, authors found that sleeping in hammock was inversely associated to scoliosis <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340998/pdf/je-25-212.pdf\" rel=\"nofollow\">(Baroni et al.)</a>. Still, it's possible that this study failed to take into account the possibility that children with scoliosis might be less likely to sleep in a hammock because of possible back pain in the morning. Correlation (or inverse correlation) does not imply causation.</p>\n", "score": 6 } ]

[ "sleep", "back", "spine", "orthopedics" ]

[ { "answer_id": 618, "body": "<p>There are a couple concerns with eating food with mold on it:</p>\n\n<ol>\n<li>The growth of mold implies that microbial contaminants can grow on the food, which means there is a potential for spoilage even if the mold itself isn't pathogenic.</li>\n<li>The mold itself can cause health problems. The <a href=\"http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/molds-on-food-are-they-dangerous_/\">USDA</a> recommends discarding molded bread, as a \"bit of mold\" that is visible likely means a much greater penetration of mold in sub-visible amounts throughout the bread as a whole.</li>\n</ol>\n\n<p>The most common health threats from the mold itself are likely exposure to <a href=\"http://en.wikipedia.org/wiki/Aflatoxin\">mycotoxins</a> or allergic reactions - consider, for example, that penicillin is a mold that can grow on bread, and also causes fairly serious allergic reactions.</p>\n\n<p>While the risk is likely small (you are exposed to tremendous numbers of molds in the process of going about your life), it's also fairly avoidable.</p>\n", "score": 13 }, { "answer_id": 630, "body": "<p>Molds, fungus and yeasts produce <a href=\"https://en.wikipedia.org/wiki/Mycotoxin\" rel=\"nofollow\">mycotoxin</a>, a toxic chemical which can cause both acute and chronic health effects via ingestion, skin contact or inhalation^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22749975\" rel=\"nofollow\">2012</a>}. The danger associated with exposure depends on the type of mycotoxin, concentration and length of exposure as well as exposed individual (age, health and sex)^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/12857779\" rel=\"nofollow\">2003</a>}. In same rare cases can be even deadly (<a href=\"https://en.wikipedia.org/wiki/Aflatoxin\" rel=\"nofollow\">aflatoxins</a>)^{<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/16330360\" rel=\"nofollow\">2005</a>}.</p>\n\n<p>In comparison, molds such as found on <a href=\"https://en.wikipedia.org/wiki/Blue_cheese\" rel=\"nofollow\">blue cheese</a> are harmless, because they contain specially cultivated bacteria and they're considered safe to eat.</p>\n\n<p>Therefore if you're not sure what kind of mold it is, for your own health your should limit your exposure to all kinds of molds, fungus and yeasts.</p>\n", "score": 4 } ]

[ "nutrition", "mold" ]

[ { "answer_id": 690, "body": "<p>There has been a lot of debate over the topic of artificial sweeteners and weight loss. Some studies say that artificial sweeteners do promote weight loss, while others argue the complete opposite, that artificial sweeteners cause weight gain. </p>\n\n<p><strong>Do artificial sweeteners in diet products affect weight loss?</strong></p>\n\n<p>Most diet products use artificial sweeteners because they provide the sweetness of sugar without adding any extra calories. How this affects weight loss is uncertain. Several studies, both long term and short term, favor each side of the debate.</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3190220?dopt=Abstract&amp;holding=npg\">A 1988 study¹</a> had two groups of obese men and women. Both groups were placed on the same diet, except that one group had aspartame, an artificial sweetener used in some diet products, added to the diet. Both groups also had regular exercise instruction. The men in both groups lost a significant amount of weight in the 12 week period, while the women, who also had good results, had more of a difference in the two groups, with the group whose diet was supplemented with aspartame losing about four more pounds on average. This showed that artificial sweeteners can help weight loss, but because the group was small (59), no firm conclusions could be drawn. </p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/9022524?dopt=Abstract&amp;holding=npg\">Another similar study²</a> also showed positive results in taking aspartame. In a group of 163 obese women, some of them assigned to have products with aspartame and some assigned to abstain from it, it was shown that having aspartame promoted more weight loss and allowed more weight control during a follow-up period. This study had more conclusive evidence than the previous study, but still not enough to be considered definite.</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/2349932?dopt=Abstract&amp;holding=npg\">One more study³</a> whose results leaned towards artificial sweeteners promoting weight loss (but still inconclusive) tested beverages with aspartame or high-fructose corn syrup (which I won't talk about because it's usually not used in diet products) on normal-weight men and women. The beverages with aspartame did appear, relative to when no beverages were given, to reduce weight in male subjects, but did not have a noticeable effect on females. Once again, this leaves us with an unsatisfactory result.</p>\n\n<p>As I mentioned earlier, there are some studies that say artificial sweeteners don't have any significant effect on weight or sometimes even promote weight gain. </p>\n\n<p><a href=\"http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full\">A long-term study in San Antonio⁴</a> studied a few thousand people and asked them how often they drank beverages with artificial sweeteners. The amount of total consumption of artificial sweeteners was then estimated. About 7 or 8 years later, the subjects were re-examined and it was found that higher consumption of artificial sweeteners may be linked with a higher body mass index (BMI) and weight gain. There are many other factors that could've changed this result, and they were handled as well as they could, but still not perfectly. Because of this, the result is once again inconclusive. The study article even says, \"There may be no causal relationship between [artificial sweetener] use and weight gain.\"</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3714671\">One last study⁵</a> also says that there is no evidence that artificial sweetener consumption \"helps weight loss or prevents weight gain.\" It showed no significant link between weight loss or gain and the amount of artificial sweeteners consumed. Of course, this study has many variables that were handled as adequately as possible, but still this leads to the real result of the experiment being inconclusive. </p>\n\n<p>As we can see, it is nearly impossible to tell how artificial sweeteners affect weight loss. They're not really bad for your health, so it is fine to have them. It does seem that the studies that showed weight loss from artificial sweetener consumption had a higher percentage of weight difference than the studies that showed other results. From this you may conclude that the benefits outweigh the risks. The only thing I can recommend is to have artificial sweeteners in moderation, just like anything else.</p>\n\n<p><strong>Is there any benefit to choosing \"diet\" products instead over plain water?</strong></p>\n\n<p>This can also be a controversial subject, but there are also studies on it. Sadly, they are inconclusive.</p>\n\n<p><a href=\"http://onlinelibrary.wiley.com/doi/10.1002/oby.20737/full\">This study⁶</a> tested men and women with two groups, one was an artificial sweetener beverage group and the other was a water group. Both groups also took part in a behavioral weight loss treatment program. The results showed that the artificial sweetener group lost more weight on average than the water group. Still, this study was not large enough and did not have sufficient enough evidence to be considered conclusive.</p>\n\n<p>Whether diet products are better than water can still depend. You can argue the same as above that the benefits of artificial beverages outweigh the risks, but you could also say that water is a safe enough choice. This is usually up to whoever is debating between diet products and water, but your doctor can be contacted if the need is really felt. </p>\n\n<hr>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3190220?dopt=Abstract&amp;holding=npg\">1</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3190220?dopt=Abstract&amp;holding=npg\">An evaluation of the effect of aspartame on weight loss.</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/9022524?dopt=Abstract&amp;holding=npg\">2</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/9022524?dopt=Abstract&amp;holding=npg\">The effect of aspartame as part of a multidisciplinary weight-control program on short- and long-term control of body weight</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/2349932?dopt=Abstract&amp;holding=npg\">3</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/2349932?dopt=Abstract&amp;holding=npg\">Effect of drinking soda sweetened with aspartame or high-fructose corn syrup on food intake and body weight</a>}</p>\n\n<p>^{[<a href=\"http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full\">4</a>] <a href=\"http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full\">Fueling the Obesity Epidemic? Artificially Sweetened Beverage Use and Long-term Weight Gain</a>}</p>\n\n<p>^{[<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3714671\">5</a>] <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/3714671\">Artificial sweetener use and one-year weight change among women</a>}</p>\n\n<p>^{[<a href=\"http://onlinelibrary.wiley.com/doi/10.1002/oby.20737/full\">6</a>] <a href=\"http://onlinelibrary.wiley.com/doi/10.1002/oby.20737/full\">The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program</a>}</p>\n\n<p>^{<a href=\"http://www.hsph.harvard.edu/nutritionsource/healthy-drinks/artificial-sweeteners/\">Harvard - Artificial Sweeteners</a>}</p>\n\n<p>^{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892765/\">Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings</a>}</p>\n", "score": 9 }, { "answer_id": 10375, "body": "<p>You should avoid products that contain artificial sweeteners because it will only promote fat storage and weight gain according to <a href=\"http://articles.mercola.com/sites/articles/archive/2014/12/23/artificial-sweeteners-confuse-body.aspx\" rel=\"nofollow noreferrer\">Dr. Mercola</a>, it also promotes health problems associated with excessive sugar consumption, including Cardiovascular disease and stroke, Alzheimer's disease and artificial sweeteners stimulate appetite, increase cravings for carbs why? simply because your body are being fooled by artificial sweeteners by sweet taste but in reality, it has no calories inside. When we eat something sweet, our brain releases dopamine which activates our brain's reward center. The appetite-regulating hormone leptin that will inform your brain that you are \"full\" if a number of calories have been ingested. However, if we consume something that tastes sweet but doesn't contain any calories, our brain are still activated by these artificial sweeteners that we get sugar (calories), but when the sugar are not present, our body will still continue to give signal that we need more that will results in carb cravings so in short we are tricked by this artificial sweeteners. The study shows that it also worsen any insulin sensitivity and are promoting weight gain. Artificial sweeteners played a role in worsening the obesity and diabetes epidemics since their emergence in our food supply and these are added to about 6,000 different beverages, snacks, and food products, making label-reading an ever pressing necessity. Disturbingly, food industry groups are now trying to hide the presence of artificial sweeteners in certain foods.</p>\n\n<p>For a safer sweetener options, I suggest using stevia or Luo Han, both of them are safe natural sweeteners. Just keep in mind however that if you struggle with hypertension, high cholesterol, diabetes, or overweight, then you have insulin sensitivity issues and would probably benefit from avoiding \"ALL sweeteners\".</p>\n", "score": 0 } ]

[ "nutrition", "sugar", "weight", "artificial" ]

[ { "answer_id": 758, "body": "<p>It is likely you are not hearing the ultrasound itself (typical frequencies are <a href=\"https://en.wikipedia.org/wiki/Medical_ultrasound\" rel=\"nofollow\">upwards of 1 MHz</a>, far beyond what the human hearing system is capable of detecting). You are probably hearing <a href=\"https://en.wikipedia.org/wiki/Coil_noise\" rel=\"nofollow\">coil whine</a> from the electronics -- <a href=\"https://en.wikipedia.org/wiki/Switched-mode_power_supply\" rel=\"nofollow\">switched-mode power supplies</a> in particular tend to operate towards the upper end of the hearing range, and the intensity of this sound changes as the power consumption does (eg. when the imaging system goes from \"idle\" to \"active\").</p>\n", "score": 17 } ]

[ "hearing", "medical-device", "ultrasounds" ]

[ { "answer_id": 1560, "body": "<p>I would like to add a brief answer in common language. The heart is a pump which pushes blood into the arteries in pulsatile manner (pushes out blood with each heart beat). As the blood is pushed in the arteries, the pressure rises to a peak called systolic pressure, which is usually around 120 mm Hg. As the heart's main chamber (left ventricle) relaxes, the pressure tends to fall. But fall in pressure is arrested by closure of a valve called aortic valve. Further fall in pressure occurs by flow of blood to peripheral tissues. The lowest limit to which the pressure falls in main arteries is called diastolic pressure and it is usually around 80 mm Hg. </p>\n\n<p>Morever, when the blood pressure is checked with a mercury instrument, the cuff around arm is inflated to about 200 mm Hg (to occlude the flow in artery of the arm) and then slowly pressure is reduced while listening to the sounds over artery in front of the elbow joint. Knocking sounds start coming at systolic pressure (usually around 120 mm Hg). These sounds disappear as the cuff pressure is lowered below diastolic blood pressure (usually around 80 mm Hg). Hence, the BP reading is said to be 120/80.</p>\n\n<p>The following figure from the <a href=\"https://en.wikipedia.org/wiki/Blood_pressure#Pulse_pressure\" rel=\"nofollow noreferrer\">Blood pressure Wikipedia page</a> should make this clearer. The notch on the downnstroke indicates point of closure of the aortic valve. </p>\n\n<p><img src=\"https://i.stack.imgur.com/BBbY8.png\" alt=\"enter image description here\"></p>\n\n<hr>\n\n<p>Edit in response to comment below: The mechanism of these sounds is not entirely clear and has been subject of study since long (see this 1929 article: <a href=\"http://www.ahjonline.com/article/S0002-8703(29)90277-5/abstract\" rel=\"nofollow noreferrer\">http://www.ahjonline.com/article/S0002-8703(29)90277-5/abstract</a> . Many theories have been proposed e.g. <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/2774311\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmed/2774311</a> . It is likely to originate from the artery wall due to vibrations created by turbulent flow that occurs when blood flow is partially obstructed (ref: <a href=\"https://www.medicine.mcgill.ca/physio/vlab/cardio/auscul.htm\" rel=\"nofollow noreferrer\">https://www.medicine.mcgill.ca/physio/vlab/cardio/auscul.htm</a>). There is no sound when the flow is totally obstructed i.e. cuff pressure greater than systolic pressure. Also, there is no sound when cuff pressure is lower than diastolic since the flow then is laminar and not turbulent. The nature of sounds (called Korotkoff sounds) also varies as pressure is lowered from systolic to diastolic and 5 phases have been identified: <a href=\"https://en.wikipedia.org/wiki/Korotkoff_sounds#The_five_Korotkoff_sounds\" rel=\"nofollow noreferrer\">https://en.wikipedia.org/wiki/Korotkoff_sounds#The_five_Korotkoff_sounds</a></p>\n\n<p>References:</p>\n\n<p><a href=\"http://www.cvphysiology.com/Heart%20Disease/HD002.htm\" rel=\"nofollow noreferrer\">Cardiac Cycle</a></p>\n\n<p><a href=\"https://en.wikibooks.org/wiki/Human_Physiology/The_cardiovascular_system\" rel=\"nofollow noreferrer\">Human Physiology/The cardiovascular system</a></p>\n", "score": 14 }, { "answer_id": 849, "body": "<p>The two numbers indicate different amounts of pressure (measured in millimeters of mercury) in the arteries at different times in the cardiac cycle. The <a href=\"http://en.wikibooks.org/wiki/Human_Physiology/The_cardiovascular_system#Cardiac_Cycle\">cardiac cycle</a> just refers to the different phases during a single beat of the heart.</p>\n\n<p>The top number is called the “systolic blood pressure.” That’s because it corresponds to the phase of the cardiac cycle called “systole,” from <a href=\"http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dsustolh%2F\">the Greek word for “contraction.”</a> That is when the ventricles of the heart are squeezing out the blood. During this phase, the pressure in the arteries is higher because the blood is being pumped into them. </p>\n\n<p>The bottom number is called the “diastolic blood pressure.” It corresponds to the phase of the cardiac cycle called “diastole,” from <a href=\"http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Ddiastolh%2F\">the Greek word for “a separation.”</a> This is the time in between the heart beats when the ventricle is relaxing. Because the blood is not actively being pushed into the vessels, this number is always lower. </p>\n\n<p><a href=\"http://en.wikibooks.org/wiki/Human_Physiology/The_cardiovascular_system#Cardiac_Cycle\">This physiology textbook</a> has a good explanation of the cardiac cycle.</p>\n\n<p>In case by “what do the numbers indicate?” you intended something about clinical outcomes, I will speak to that briefly. </p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/12698068\">People argue about</a> whether systolic or diastolic blood pressure is a more important during treatment of high blood pressure. The answer probably varies according to age, among other factors. The most widely used (in the US) <a href=\"http://jama.jamanetwork.com/article.aspx?articleid=1791497\">consensus guidelines</a> state;</p>\n\n<blockquote>\n <p>There is strong evidence to support treating hypertensive persons aged 60 years or older to a BP goal of less than 150/90 mm Hg and hypertensive persons 30 through 59 years of age to a diastolic goal of less than 90 mm Hg; however, there is insufficient evidence in hypertensive persons younger than 60 years for a systolic goal, or in those younger than 30 years for a diastolic goal, so the panel recommends a BP of less than 140/90 mm Hg for those groups based on expert opinion.</p>\n</blockquote>\n", "score": 13 } ]

[ "blood-pressure", "cardiology", "biological-parameter" ]

[ { "answer_id": 1304, "body": "<p>Vitamin D is produced in the skin, not the eyes.<a href=\"http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/\">(1)</a></p>\n\n<p>I would imagine that when those indigenous peoples were introduced to sunglasses, they were also introduced to a number of other items they had never previously known, such as tobacco, alcohol and fast food. Diseases they had no immunity to might also have played a role. </p>\n\n<p>The synthesis of vitamin D is well understood and sources describing it can be found in many places so I'm not going to quote the entire process, but a good explanation can be found <a href=\"http://ajcn.nutrition.org/content/80/6/1678S.full\">here under the heading \"PHOTOSYNTHESIS OF VITAMIN D\"</a>. In short, it's a passive process that occurs in the skin and is not regulated by the brain, eyes, or other organs. What determines the amount of vitamin D synthesized by the body? Solely the amount of UVB photons penetrating the skin and the person's age:</p>\n\n<blockquote>\n <p>Anything that either influences the number of solar UVB photons that penetrate the skin or alters the amount of 7-dehydrocholesterol in the skin influences the cutaneous production of vitamin D3. The amount of 7-dehydrocholesterol in the epidermis is relatively constant until later in life, when it begins to decline (17, 18). <a href=\"http://ajcn.nutrition.org/content/80/6/1678S.full\">Ibid., \"FACTORS THAT ALTER THE CUTANEOUS PRODUCTION OF VITAMIN D3\"</a></p>\n</blockquote>\n\n<p>There are no other factors mentioned in synthesis, and as you can see from the diagram <a href=\"http://ajcn.nutrition.org/content/80/6/1678S/F3.large.jpg\">here</a> there is no involvement of the eyes or brain in vitamin D physiology at any point. Could there be an indirect involvement of the brain since it also controls the parathyroid glands? Yes, there could, but that wouldn't change the results of how we measure vitamin D levels.</p>\n\n<p>Therefore, an assertion that the eyes are involved in vitamin D deficiencies is purely speculative and the burden of providing evidence for it would be on the person making the assertion. I can find no evidence to support the notion. It's also a little odd considering that a huge number of people living in developed countries have been wearing sunglasses for many decades without ill effect. Why would we have not seen this effect long ago? Is it possible these indigenous peoples have unique genetic differences that altered their basic mammalian vitamin D physiology and somehow caused their eyes to be involved? Well, anything's possible, but that would be an <em>astonishing</em> finding and it also is purely speculative.</p>\n", "score": 10 } ]

[ "dermatology", "eye", "micronutrients", "vitamin-d" ]

[ { "answer_id": 1835, "body": "<p>There is one systematic review on this topic. <a href=\"http://ajcn.nutrition.org/content/early/2015/07/01/ajcn.115.109553.full.pdf+html\" rel=\"noreferrer\">This study</a> was published in the American Journal of Clinical Nutrition, which is the most respected journal in their discipline. As so, I consider this study perhaps the most important publication on this topic. Main conclusion was that the literature is scarce with regard to <em>intermittent fasting</em>. Small studies have been published, and these studies have shown positive outcomes with intermittent fasting. It is evident that these findings must be replicated in a study population reaching 1000+ participants.</p>\n\n<p>Some sources claims that currently they are conducting the largest study in intermittent fasting in Sweden, lead by professor Kerstin Brismar. Apparently the preliminary results are encouraging. No published studies are yet available. Following pages (in Swedish) have some more information: <a href=\"http://www.svt.se/nyheter/vetenskap/5-2-fungerar\" rel=\"noreferrer\">svt.se</a> &amp; <a href=\"http://ki.se/forskning/kerstin-brismar-star-upp-for-52-dieten\" rel=\"noreferrer\">Karolinska Institutet</a>. Prof Brismar is a well-known researcher in metabolism and has a great credibility in her field. I am looking forward to their results.</p>\n\n<p>There are hardly any <em>harms</em> with intermittent fasting, I think. But I think it has a great pit fall. One must have strong spirit and psyche, since the human nature has a tendency to give \"rewards\". In this case it means that after two fasting days one should not eat more than is normal (+no candy etc.), since this would ruin the meaning of the diet. </p>\n", "score": 6 } ]

[ "nutrition", "diet" ]

[ { "answer_id": 1417, "body": "<p>There are quite a few things you can do to \"reset\" your sleep schedule, as shown by <a href=\"http://www.webmd.com/sleep-disorders/features/reset-sleep-cycle\">this WebMD article</a>. However, be aware that due to your own circadian rhythms, that may not be the optimal pattern for you. Some of the suggestions include:</p>\n\n<ol>\n<li>Bright lights - Use bright lights around you when you first get up.</li>\n<li>Dim lights - Conversely, use dim lights in the evening.</li>\n<li>Don't lay awake - If you tend to lay awake for a while, do something else before you go to bed.</li>\n<li>Time meals - Use your meal times to help your body adapt to when to sleep. If you eat at irregular times, it can throw off your body.</li>\n<li>Limit caffeine intake (Especially later in the day)</li>\n</ol>\n\n<p>There are a few other suggestions in the article, especially relating to travel. One of the other suggestions is supplementing with melatonin, but as can be seen by <a href=\"http://www.ncbi.nlm.nih.gov/books/NBK11941/\">this study review</a>, many of the studies are not very well done, and a few directly refute melatonin being a sleep aid.</p>\n\n<p>If you have trouble adjusting to a more traditional sleep schedule, you may want to look at biphasic sleeping (2, 4 hour sleep shifts) or contact a sleep center for help.</p>\n", "score": 9 }, { "answer_id": 1414, "body": "<p>You should just stick to the new desired sleep routine and then accept that you'll have a jet lag for a some time. You may not sleep well the first few days, but you should force yourself to get up at the scheduled wake-up time. If you want to set your biological clock 6 hours back, then it may take a week before you're fully adapted to the new routine.</p>\n\n<p>Make sure your bedroom is dark during sleeping time. After a few days into the new routine you should exercise, even if due to excessive sleepiness you don't feel like doing so. A potential problem a few days into the new routine can be that you have accumulated a sleep deficit due to not sleeping well a few days, but this will affect your brain far more than your body. If you give in to that by avoiding physical activity, then you may continue to sleep badly and the change to the new routine may take longer.</p>\n\n<p>Of course, if you feel very sleepy, you should not exercise as fanatically as you are used to. Just start slowly (compared to your usual exercise routine), you may feel that during the exercise session the sleepiness goes away and stays away quite some time after you've finished. That's the desired effect, your body is then fully awake, and that allows you to sleep better at night.</p>\n", "score": 2 } ]

[ "sleep-cycles", "productivity" ]

[ { "answer_id": 1294, "body": "<p>A <a href=\"https://en.wikipedia.org/wiki/California_Proposition_65_(1986)\">California Proposition 65</a> warning doesn't really tell you anything about the safety of the luggage.</p>\n\n<p>Proposition 65 <em>requires</em> warnings if somebody may be exposed to a substance that has a 1 in 100,000 chance of causing cancer over the course of 70 years, or has the possibility of causing birth defects or reproductive harm, as determined by the <a href=\"https://en.wikipedia.org/wiki/California_Office_of_Environmental_Health_Hazard_Assessment\">California Office of Environmental Health Hazard Assessment</a>.</p>\n\n<p>However, there is nothing preventing warnings even if there is no risk whatsoever. Proposition 65 permits members of the general public to sue over missing warnings, and California has a cottage industry of lawyers filing these suits any time they find something that doesn't have such a warning. As a result, these warnings are often used as an incantation to ward off lawyers rather than an actual indication of hazard. See, for example, <a href=\"http://ag.ca.gov/prop65/pdfs/G035101.pdf\">Consumer Defense Group v. Rental Housing Industry members</a>, where the list of potential carcinogens included \"automobile exhaust from cars in the parking lot\" and \"the possibility that someone on the grounds of the apartment building might be smoking a cigarette\". As part of the initial settlement of that suit, a warning was posted at the entrance to each building referring to a two-page list of things that might reasonably be found in or around an apartment building -- not because the apartment had lead-based paint, or used perchloroethylene cleaners, or had asbestos insulation, but to prevent further lawsuits.</p>\n", "score": 11 }, { "answer_id": 17021, "body": "<p>I think the currently accepted answer is incorrect on a number of points. The official <a href=\"https://oehha.ca.gov/proposition-65/proposition-65-faqs\" rel=\"noreferrer\">California Proposition 65 (aka OEHHA) site FAQ</a>, has more accurate information. There is also another <a href=\"https://oag.ca.gov/prop65/faqs-view-all\" rel=\"noreferrer\">FAQ from the Attorney General</a>, which answers the question as well. The OEHHA site says:</p>\n\n<blockquote>\n <p>The purpose of Proposition 65 is to notify consumers that they are being exposed to chemicals that are known to cause cancer and/or reproductive toxicity. Consumers can decide on their own if they want to purchase or use the product. A Proposition 65 warning does not necessarily mean a product is in violation of any product-safety standards or requirements. For additional information about the warning, contact the product manufacturer.</p>\n</blockquote>\n\n<p>The currently accepted answer claims that \"Proposition 65 requires warnings if somebody may be exposed to a substance that has a 1 in 100,000 chance\", which is not true. Simply being exposed to a chemical that has a certain risk does not make the company required to post a warning. The chemical <strong>also</strong> has to be on <a href=\"https://oehha.ca.gov/proposition-65/proposition-65-list\" rel=\"noreferrer\"><strong><em>the list</em></strong></a>. There could be substances which have risk, but are not on the list, and thus they are not required to post a warning. </p>\n\n<p>Here is a quote directly from the <a href=\"https://oehha.ca.gov/proposition-65/proposition-65-faqs\" rel=\"noreferrer\">OEHHA site</a>, which shows the substance not only has to be on the list, but also has to be in a high enough concentration to create an unsafe exposure: </p>\n\n<blockquote>\n <p>Proposition 65 applies only to exposures to listed chemicals. It does not ban or restrict the use of any given chemical. The concentration of a chemical in a product is only one part of the process to determine whether consumers must be warned about an exposure to a listed chemical.</p>\n</blockquote>\n\n<p>The currently accepted answer is also incorrect in that it claims \"However, there is nothing preventing warnings even if there is no risk whatsoever.\" This is blatantly false, because the law allows a business to prove that their use falls below the acceptable use threshold. Here is a quote directly from the <a href=\"https://oag.ca.gov/prop65/faqs-view-all#3GP\" rel=\"noreferrer\">California Attorney General's site</a>: </p>\n\n<blockquote>\n <p><strong>Exposures that pose no significant risk of cancer</strong>: A warning about listed chemicals known to cause cancer (\"carcinogens\") is not required if the business can demonstrate that the exposure occurs at a level that poses \"no significant risk.\" This means the exposure is calculated to result in not more than one excess case of cancer in 100,000 individuals exposed over a 70-year lifetime. The Proposition 65 regulations identify \"no significant risk\" levels for certain carcinogens. The most recent list of no significant risk levels can be found here: <a href=\"http://www.oehha.ca.gov/prop65/getNSRLs.html\" rel=\"noreferrer\">http://www.oehha.ca.gov/prop65/getNSRLs.html</a>.</p>\n</blockquote>\n\n<p>Thus, businesses have the possibility to show their product is safe, and not post a warning even if it contains a chemical from the list. Small companies of <a href=\"https://oehha.ca.gov/proposition-65/proposition-65-faqs\" rel=\"noreferrer\">less than 10 employees</a> are exempted having to post a warning.</p>\n\n<p>If a large company thinks it's cheaper for them to place warnings on all of their products, than it would be for them to do testing to see if their product is safe for consumers, that seems a bit of a red flag to me.</p>\n\n<p>I found a particular product I purchased came with a warning, but when I looked on the company website though they acknowledged the warning, they wouldn't let their consumers know which offending chemicals were. This law is about the <a href=\"https://oag.ca.gov/prop65/faqs-view-all#5GP\" rel=\"noreferrer\">consumers \"right to know\"</a>. If the business posts a warning, but won't let you know what the chemicals are that are the cause for that warning, it seems a bit of a red flag to me as well. If consumer safety is not an important enough issue for a company to do the testing, it seems safer to me to just avoid those products where possible.</p>\n\n<p>One more useful tidbit of information is that, according to the Attorney General, Proposition 65 has been <a href=\"https://oag.ca.gov/prop65/faqs-view-all#8GP\" rel=\"noreferrer\">successful in motivating businesses to eliminate or reduce toxic chemicals in numerous consumer products</a>. This law is not only about helping consumers make informed decisions, it's about motivating companies to be more responsible for the safety of their consumers.</p>\n", "score": 7 } ]

[ "cancer" ]

[ { "answer_id": 1326, "body": "<p>The human (and other animals) upper digestive tract is 'designed' to ingest relatively large (compared to most pills), soft, moist boluses. The muscles of the tongue and pharynx can propel these kinds of objects (including liquid) into the esophagus with ease, unless there is some specific pathology at work. Chewing also tends to naturally push food toward the swallowing position.</p>\n\n<p>The tablets and capsules you asked about, on the other hand, tend to be dry and hard and are not chewed. There is little for the tongue and throat muscles to 'grab' as they try to push the object back to where it can actually enter the esophagus. They also tend to get stuck because of their dryness.</p>\n\n<p>Once you have actually swallowed a pill without water or food to help it along, the difficulty for the ingestion process does not end. The esophagus also has difficulty pushing them down to the stomach, though gravity helps. Sometimes they do end up lodged in the esophagus where they ultimately dissolve and pass on down, but not before they may have caused damage to the lining of the esophagus from their caustic properties or just from the pressure of it's presence.</p>\n\n<p>The struggle is your tongue and throat telling you, \"You are asking me to do something I wasn't designed to do!\"</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597750/\">Anatomy and Physiology of Feeding and Swallowing – Normal and Abnormal</a> is an excellent discussion of human swallowing by Koichiro Matsuo, DDS, PhD and Jeffrey B. Palmer, MD.</p>\n", "score": 14 } ]

[ "medications" ]

[ { "answer_id": 1996, "body": "<p>This is very good and pragmatic question. I will answer no.</p>\n\n<p>First of all, there are no studies to date which would have investigated the life expectancy after cholecystectomy. Of course this statement can be hardly profoundly backed up, but if you search <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/?term=cholecystectomy%20AND%20%22life%20expectancy%22\">PubMed with \"cholecystectomy AND \"life expectancy\"</a>, none of the studies will look at this issue.</p>\n\n<p>There is a <a href=\"http://www.nice.org.uk/guidance/IPG508\">NICE guideline</a> and a recently published <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/26200981\">review article in NEJM</a>, which does not take any stance about the long term disadvantages such as reduced life expectancy after cholecystectomy. Moreover, laparoscopic cholecystectomies have been performed since 1985 and <a href=\"http://emedicine.medscape.com/article/1900692-overview\">open cholecystectomies since 1882</a>. <a href=\"http://emedicine.medscape.com/article/1582261-overview\">700 000 cholecystectomies</a> are performed annually only in the US.</p>\n\n<p>Considering that cholecystectomies have been performed more than 130 years and the total number performed only in US is probably some where around +10 mil, I am fairly certain that if this operation would indeed have definitive adverse long term effects, they would have been even suggested if not partly shown by some investigator some where to date.</p>\n\n<p>Finally, even tough some investigator would stated that cholecystectomy is associated to reduced life expectancy, according to <a href=\"https://en.wikipedia.org/wiki/Bradford_Hill_criteria\">Hill´s principles</a> we should also be able to have some sort of plausibility in order to have causality between these two. I can´t up some up with reasonable plausibility at this moment....</p>\n", "score": 9 } ]

[ "gastroenterology", "lasting-effects-duration", "life-expectancy", "gallbladder", "cholecystectomy" ]

[ { "answer_id": 3735, "body": "<p>Referring to published <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/\">research</a>, there is no known quota on drinking frequency since fluid intake from beverages and food in time period takes care of the total hydration status of an individual in a day. Daily consumption below the range of adequate intake of water may not produce harmful effects to the body because hydration is received from intake of beverages and foods other than the normal water intake.</p>\n\n<p><a href=\"http://www.nap.edu/read/10925/chapter/6#74\">Research</a> into hydration reveals humans must maintain water balance in order to stay healthy. Humans receive hydration i.e. water from daily food and water intake, and generally lose water in the form of sweat, urine and exhalation. Drinking water is beneficial in those with a water deficit particularly due to dehydration which can be caused by other factors such as diarrhea, vomiting, burns etc.</p>\n\n<p>The recommendations on adequate intake of water which includes total water intake (water from beverages and food) is found <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/table/T6/\">here</a>.</p>\n\n<blockquote>\n <p>Over the course of a few hours, body water deficits can occur due to reduced intake or increased water losses from physical activity and environmental (e.g., heat) exposure. However, on a day-to-day basis, fluid intake, driven by the combination of thirst and the consumption of beverages at meals, allows maintenance of hydration status and total body water at normal levels.</p>\n</blockquote>\n", "score": 7 }, { "answer_id": 19920, "body": "<p>In a recent Time magazine article, they reference a 2015 study in The American Journal of Clinical Nutrition about recommended water drinking frequency, &quot;<a href=\"https://academic.oup.com/ajcn/article/103/3/717/4564598\" rel=\"nofollow noreferrer\">A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index:</a>&quot;</p>\n<blockquote>\n<p>Sipping water (or any other beverage) a little bit at a time prevents the kidneys from being “overloaded,” and so helps the body retain more H2O, Nieman says.</p>\n<p>The take-home message isn’t that people should drink less water, nor that they should swap out water for other beverages. But for those hoping to stay optimally hydrated, a slow-and-steady approach to water consumption and coupling water with a little food is a more effective method than knocking back full glasses of H2O between meals. “Water is good for you, but you can drown in it too,” Nieman says.</p>\n</blockquote>\n<p>The entire article is worth a read and might drastically change the way the public views hydration: <a href=\"https://time.com/5646632/how-much-water-to-drink/\" rel=\"nofollow noreferrer\">&quot;Why Drinking Water All Day Long Is Not the Best Way to Stay Hydrated.&quot;</a></p>\n", "score": 3 } ]

[ "nutrition", "water", "dosage" ]

[ { "answer_id": 5301, "body": "<p>High quality custom ear plugs (e.g., <a href=\"http://www.etymotic.com/consumer/hearing-protection/erme.html\" rel=\"nofollow\">http://www.etymotic.com/consumer/hearing-protection/erme.html</a> although all custom plug are essentially the same materials) are essentially identical to the molds used in some hearing aids. Hearing aid users are encouraged to use their aids all day every day. Increased build up of ear wax can be a problem, but can easily be treated at home. Cheaper foam ear plugs can deteriorate in the canal and add debris.</p>\n", "score": 4 } ]

[ "hearing", "otolaryngology", "audiology", "earplugs-earphones", "tinnitus" ]

[ { "answer_id": 4273, "body": "<p>Reference 1 refers to studies that trail various combinations of analgesics. Of note is the study concerning paracetamol (acetaminophen) and ibuprofen. </p>\n\n<p>The study compared the adverse effects of 4 groups:</p>\n\n<ol>\n<li>paracetamol </li>\n<li>ibuprofen </li>\n<li>paracetamol and ibuprofen, and; </li>\n<li>placebo.</li>\n</ol>\n\n<p>They found \"adverse events (significant difference)\" consisted of:</p>\n\n<ul>\n<li>Vomiting: 24%–32% </li>\n<li>Drowsiness: 5% </li>\n<li>Abdominal pain: 3%–10% </li>\n</ul>\n\n<p>And stated that the \"paracetamol group was drowsier than other groups.\"</p>\n\n<p>Reference 1 states: \"Combining [the two] analgesics may increase the incidence of adverse effects.\"</p>\n\n<p>A similar clinical trial was described in Reference 2. The paper found that adverse events were \"numerically higher in the groups receiving combination tablets.\"</p>\n\n<p>From this it can concluded that the likelihood of experiencing adverse effects is increased by combination of the two analgesics.</p>\n\n<p>I could not find anything solid in regards to your last question. The increased likelihood of experiencing adverse effects may be due to the two agent's similar mechanism of action. Reference 3 states: \"Due to their mechanisms of action, using paracetamol and ibuprofen together theoretically increases the risk of renal and hepatic toxicity.\" It is possible that this extends to other adverse effects.</p>\n\n<p><strong>References</strong></p>\n\n<ol>\n<li>Combining Paracetamol (Acetaminophen) with Nonsteroidal Antiinflammatory Drugs: A Qualitative Systematic Review of Analgesic Efficacy for Acute Postoperative Pain, <a href=\"http://www.endoexperience.com/documents/APAPOngetal.pdf\" rel=\"nofollow\">http://www.endoexperience.com/documents/APAPOngetal.pdf</a></li>\n<li>Paracetamol, ibuprofen, or a combination of both drugs against knee pain: an excellent new randomised clinical trial answers old questions and suggests new therapeutic recommendations, <a href=\"http://ard.bmj.com/content/70/9/1521.full\" rel=\"nofollow\">http://ard.bmj.com/content/70/9/1521.full</a></li>\n<li>Evidence that alternate dosing of paracetamol and ibuprofen in children with fever may reduce temperature: other benefits uncertain <a href=\"http://www.bpac.org.nz/BPJ/2014/July/docs/BPJ62-news.pdf\" rel=\"nofollow\">http://www.bpac.org.nz/BPJ/2014/July/docs/BPJ62-news.pdf</a></li>\n</ol>\n", "score": 3 } ]

[ "side-effects", "nsaids-pain-meds", "analgesics", "mechanism-of-action", "acetaminophen" ]

[ { "answer_id": 17671, "body": "<p>i agree with Ramyar, since CTS is the result of nerves in the wrist area (on the palmar side) being stuck and under pressure due to direct and prolonged pressure (while using mouse, keyboard, etc.-but most cases are idiopathic) and narrowing of the tunnel through which the nerve passes(due to thickening of the sheaths, tendons etc. as a result of constant pressure on the spot) and finally damage to the nerves; any activity helping to widen the canal and to lift the pressure off the nerves in a suffice proper interval, to stretch tendons and also at the same time, to strengthen the muscles supporting wrist- both flexors and extensors- will most probably help counteract the pathophysiology of CTS.(exercises with tools like powerballs which provide pressure outwards so they help stretch your wrist while also strengthening it and the muscles (flexors) that support it by squeezing the ball ,and etc.- but should keep in mind that you also need to strengthen your extensors too, and to avoid direct and high pressure to the base of your palm and the wrist) BUT!!! you should always be careful about any exercise you are going to do with delicate parts like your wrist, and if you are suffering or are concerned about your wrist, you'd better pay a visit to your doctor for proper evaluation and counseling. if you hurt your wrist or your median nerve passing through carpal tunnel, it will take quite a while to fully recover if any recovery.\n<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668198/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668198/</a>\n<a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5820891/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5820891/</a>\nthere are also findings that disprove any of such discussions\n<a href=\"https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072780/\" rel=\"nofollow noreferrer\">https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072780/</a></p>\n", "score": 2 }, { "answer_id": 5870, "body": "<p>as a medical doctor I have not seen such a phenomenon !your ability as a professional guitarist can be affected by working with such devices due to the fact that these device may increase the muscular tones ! but it does not related to CTS.</p>\n", "score": 0 } ]

[ "exercise", "carpal-tunnel-syndrome" ]

[ { "answer_id": 5227, "body": "<p>This is a really interesting question, because it really isn't as easy as people being a bit more susceptible in the winter. There's no definitive answer yet.</p>\n\n<p><a href=\"http://jvi.asm.org/content/81/11/5429.full\" rel=\"noreferrer\">Influenza Seasonality: Underlying Causes and Modeling Theories</a> says:</p>\n\n<blockquote>\n <p>In temperate climates, flu infections at whatever level of intensity are characterized by a flu season. In these areas, the disease is thought to exist at a low level throughout the year but exhibit a marked seasonal increase, typically during the winter months. Influenza epidemics and outbreaks occur in tropical areas as well, although the timing and impact are not as well defined</p>\n</blockquote>\n\n<p>The exact reason why this flu season happens are not known, but a few things come together that are good for influenza:</p>\n\n<ul>\n<li><a href=\"http://www.plospathogens.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.ppat.0030151&amp;representation=PDF\" rel=\"noreferrer\">Dry, cold air favors transmission</a> - especially <a href=\"http://www.sciencedirect.com/science/article/pii/S0163445315001061\" rel=\"noreferrer\">dry air</a> is good for it, both for transmission and survival on, for example, surfaces. Heating during the winter decreases humidity inside, while the cold air outside is always less humid.</li>\n<li><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870528/\" rel=\"noreferrer\">Vitamin D is thought to help against infection</a> - during the winter, vitamin D production by the body is lower. </li>\n</ul>\n\n<p>Things that are debated:</p>\n\n<ul>\n<li>Crowding and being inside more might be a factor, with people being closer together because they spend a lot of time indoors.</li>\n</ul>\n\n<p>As for the second question:</p>\n\n<blockquote>\n <p>If nobody was sick before winter, where are the viruses coming from?</p>\n</blockquote>\n\n<p>Well, there's a whole different hemisphere \"down\" from where you probably are, where they have the flu season while the Northern Hemisphere is mostly healthy :) <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145127/\" rel=\"noreferrer\">Air travel is convenient for influenza.</a> Even without it, we'd still have influenza during the winter, though - as mentioned above it <em>does</em> occur in tropical areas and can spread from there. Also, humans aren't the only species to carry around influenza - <a href=\"http://www.cdc.gov/flu/about/viruses/transmission.htm\" rel=\"noreferrer\">wild birds are one of the primary sources of influenza</a>.</p>\n\n<blockquote>\n <p>Do people with a constantly weakened immune system (e.g. AIDS) catch flu in summer too?</p>\n</blockquote>\n\n<p>Well, everyone can - it's unlikely, <a href=\"http://cid.oxfordjournals.org/content/39/4/595.full\" rel=\"noreferrer\">but it does happen</a>. And as flu season passes, there just aren't many people around that you can catch it from.</p>\n", "score": 11 }, { "answer_id": 23660, "body": "<p>Well, since you already have a well-written answer, I just wanted to add this as another possible cause:</p>\n\n<p>Research done by the National Institute of Child Health and Human Development (NICHD) in 2008 found that the influenza virus has a butter-like coating. The coating melts when it enters the respiratory tract. In the winter, the coating becomes a hardened shell; therefore, it can survive in the cold weather similar to a spore. In the summer, the coating melts before the virus reaches the respiratory tract.</p>\n\n<p>Source: <a href=\"https://zenodo.org/record/1233359#.Xr9iDmnhUzQ\" rel=\"nofollow noreferrer\">https://zenodo.org/record/1233359#.Xr9iDmnhUzQ</a></p>\n\n<p>Really cool question, by the way!</p>\n", "score": 2 } ]

[ "disease-transmission", "influenza", "weather", "seasonal-allergies", "air-temperature" ]

[ { "answer_id": 9334, "body": "<p><strong>1.</strong> Freezing cold (4 °C) beverages do not increase the secretion of the gastric acid more than lukewarm or hot beverages, according to this study:</p>\n\n<p><em>McArthur KE et al, Gastric acid secretion, gastrin release, and gastric emptying in humans as affected by liquid meal temperature (<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/2912011\" rel=\"nofollow\">PubMed</a>).</em></p>\n\n<blockquote>\n <p>Coffee (360 mL) was infused into the stomach through a nasogastric\n tube at 58 (steaming hot), 37, or 4 degrees C (ice cold). Intragastric\n temperature, measured by an intragastric temperature sensor attached\n to the nasogastric tube, returned to body temperature 16.7 +/- 2.7 min\n after the hot meal and 23.8 +/- 1.1 min after the cold meal. Gastric\n acid secretion increased after hot, warm, and cold coffee but <strong>the\n initial temperature of the meal had no effect on gastric acid\n secretion.</strong></p>\n</blockquote>\n\n<p><strong>2.</strong> Cold beverages slow down stomach emptying, that is passing of food from the stomach into the small intestine, according to this study:</p>\n\n<p><em>Collares EF et al, 1981, Gastric emptying in children. I. Influence of the temperature of a hydration solution for oral use (<a href=\"http://www.ncbi.nlm.nih.gov/pubmed/7340752\" rel=\"nofollow\">PubMed</a>)</em> </p>\n\n<blockquote>\n <p>Each baby had measured its gastric emptying for two different\n temperature solutions, approximately 27 degrees C and 4 degrees C,\n room and cold temperature...The results showed a <strong>significant larger\n gastric retention for low temperature one.</strong></p>\n</blockquote>\n\n<p>This suggests that drinking cool water after the meals can slow down the digestion a bit and possibly cause an uncomfortable feeling of prolonged stomach fullness. This could be what the OP's parents referred to as \"blockage.\"</p>\n\n<p>As mentioned in the first study above, freezing cold (4 °C) coffee changes to the body temperature in about 20 minutes after it reaches the stomach, so it should not \"freeze\" the fats in the same sense as it can on the plate.</p>\n\n<p>In conclusion, from the limited evidence presented above, it seems that cool water drunk with meals might cause some stomach discomfort after the meals. Someone would need to be quite observant to become aware of such feelings.</p>\n", "score": 5 }, { "answer_id": 7065, "body": "<p>No, drinking cold water will not freeze the \"oil\" (?) in your body, and will not cause any blockage. </p>\n\n<p>However, freezed ultra cold water (salted water or alcohol can reach -15°C and stay liquid), can cause cold \"burns\" (not sure of the word, but it harms your skin anyway), just like winter burns on your hand if you play too long with snow.</p>\n\n<p>This is part of the <a href=\"https://en.wikipedia.org/wiki/Thermoregulation_in_humans\" rel=\"nofollow\">human thermoregulation process</a>, which is done (in part) by the hypothalamus (a part of the brain, grossly).</p>\n\n<p>Concerning your stomach, I cannot say if it will produce more acid or anything due to cold water consumption. However, any water consumption will tend to dilute the secretions, making digestion a bit longer. </p>\n\n<p>If you want to know how your body can produce heat, it can simply be by burning fat or activating muscles (this is also the reason why you shake tooth in freezing cold outside temperature).</p>\n", "score": 0 } ]

[ "water" ]

[ { "answer_id": 14144, "body": "<p>There seems to be a misconception at the driving part of the question. <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340807/\" rel=\"nofollow noreferrer\">Exercise</a> has more effects (on the brain) than just <a href=\"https://en.wikipedia.org/wiki/Chemical_synapse\" rel=\"nofollow noreferrer\">stimulating</a> a few <a href=\"https://en.wikipedia.org/wiki/Synapse\" rel=\"nofollow noreferrer\">synapses</a>. That is indeed a vague and vastly incomplete conception. Since brain chemistry is by far not completely understood it is also quite premature to believe we would be able to define some kind of \"optimal\" endorphine production. These <a href=\"https://en.wikipedia.org/wiki/Neuropeptide\" rel=\"nofollow noreferrer\">neuropeptides</a> are short acting and produced and released, signalling and reabsorbed as needed. Endorphins are quickly broken down by <a href=\"https://en.wikipedia.org/wiki/Protease\" rel=\"nofollow noreferrer\">proteases</a>. So what we do know to directly answer the question: not long. </p>\n\n<p>What we do know about the brain from pharmacology and neuroscience is that it is not operating and optimisable like a belt-fed machine gun when it comes to releasing <a href=\"https://en.wikipedia.org/wiki/Neurotransmitter\" rel=\"nofollow noreferrer\">transmitters</a>. This system strives over-all for a certain kind of balance, equilibrium or <a href=\"https://en.wikipedia.org/wiki/Homeostasis\" rel=\"nofollow noreferrer\">homeostasis</a>. You <a href=\"https://en.wikipedia.org/wiki/Neuromodulation\" rel=\"nofollow noreferrer\">regulate</a> one thing up, the brain <a href=\"https://en.wikipedia.org/wiki/Downregulation_and_upregulation#Downregulation_and_upregulation_of_receptors\" rel=\"nofollow noreferrer\">regulates this down again</a>. Flood the brain with <a href=\"https://en.wikipedia.org/wiki/Nicotine#Pharmacology\" rel=\"nofollow noreferrer\">nicotine</a>, that stimulates or blocks certain receptors, which in turn are altered in their number to compensate for this over the top supply. This does not mean the <a href=\"https://en.wikipedia.org/wiki/Neurochemistry\" rel=\"nofollow noreferrer\">neurochemistry</a> cannot be influenced. </p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/18296435\" rel=\"nofollow noreferrer\">Exercise can make you feel good</a>. But that feeling <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26438875\" rel=\"nofollow noreferrer\">does not</a> depend on <a href=\"https://en.wikipedia.org/wiki/Endorphins\" rel=\"nofollow noreferrer\">endorphines</a> <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/20353785\" rel=\"nofollow noreferrer\">alone</a>:</p>\n\n<blockquote>\n <p>While endocannabinoids seem to contribute to the motivational aspects of voluntary running in rodents, influencing the total distance covered most likely via CB1 receptors, they are less involved in the long-term changes of emotional behavior induced by voluntary exercise.</p>\n</blockquote>\n\n<p>As usual human behaviour and experience is more than just some biochemicals floating around. Any human is much more than the collection of some neurotransmitters and more than the sum of some electricity circuits:</p>\n\n<blockquote>\n <p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/1543149\" rel=\"nofollow noreferrer\">Dissociating runners use a cognitive style in which they cut themselves off from the sensory feedback they would normally receive from their body. Marathon runners demonstrated high hypnotic susceptibility scores. Additionally, use of dissociation as a running strategy during the marathon was positively related to susceptibility, and runners who dissociated in training had higher susceptibility scores than did other runners. Runner's high was not related to hypnotic susceptibility; however, it was positively related to dissociation. The most common description of runner's high was general relaxation, whereas the least used description was total euphoria. <strong>Surprisingly some runners defined runner's high in ambivalent or negative terms.</strong> These results were related to the processes of self-hypnosis and to the positive mental health benefits of running.</a></p>\n</blockquote>\n\n<p>Trying to use this exercise related 'legal high' sounds like a natural substitute. And of course, natural means safe:</p>\n\n<blockquote>\n <p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/3532354\" rel=\"nofollow noreferrer\">Endurance athletes: physiologic changes and nonorthopedic problems.</a> <br>\n The current increased participation in long distance running and endurance events brings new challenges to the physician. Adaptive changes of exercise must be differentiated from disease states. Left ventricular hypertrophy, Wenckebach rhythm, elevated creatine kinase (myocardial fraction), gastrointestinal bleeding, hematuria, hemoglobinuria, amenorrhea, and apparent anemia may all be exercise related. New syndromes have arisen--from \"runner's high\" to athletic amenorrhea. These dedicated athletes can be difficult patients. They are highly motivated and will continue training despite significant pain and danger of permanent damage. Speaking their language--carbohydrate loading, \"the bonk,\" \"slow twitch,\" \"the wall\"--is helpful in their treatment. Traditional health problems are less likely to bring the fitness addict to the physician than some new and peculiar disorders.</p>\n</blockquote>\n\n<p>This is just to remind you that going after the maximal effect of endorphine related happiness through sports may lead to addictive behaviour that is not good at all. It is by no means to be read as an advice to abstain from sport, if you like it:</p>\n\n<blockquote>\n <p><a href=\"https://www.ncbi.nlm.nih.gov/pubmed/25413542\" rel=\"nofollow noreferrer\">Does sport really produce positive effects in mental illness? The author discusses this question, through a survey of the literature. There is evidence that exercise increases endorphine levels. In order to support the prevention and treatment of depression through sport, it seems particularly useful, to encourage the practice of moderate, diversified physical activity.</a></p>\n</blockquote>\n\n<p>Still looking to get a good dose of elevated endorphines (and a generally healthy mixup for your brain chemistry)? Then here is something that is more fun:</p>\n\n<p><a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3267132/\" rel=\"nofollow noreferrer\">Social laughter is correlated with an elevated pain threshold.</a></p>\n", "score": 4 } ]

[ "exercise", "brain", "endorphins", "lasting-effects-duration" ]

[ { "answer_id": 13843, "body": "<p>It shouldn't be such a surprise that <a href=\"https://link.springer.com/article/10.1007%2FBF01541556?LI=true\" rel=\"noreferrer\">both sexes</a> can experience the behaviour described in the question at night, \"<a href=\"http://psycnet.apa.org/record/1978-11323-001\" rel=\"noreferrer\">involuntarily</a>\".</p>\n\n<p>During waking hours there are mainly <a href=\"http://psycnet.apa.org/record/1986-20115-001\" rel=\"noreferrer\">several distractions</a> in your mind that counteract (previously this would have been \"<a href=\"http://journals.lww.com/jonmd/Citation/1958/08000/RECALL_OF_SOME_PHENOMENA_OF_SLEEP__A_Comparative.3.aspx\" rel=\"noreferrer\">control</a>\") these processes.</p>\n\n<p>But since this rather complex yet basic behaviour is a combination of \"mind and matter\", that is the brain and other organs, this question is primarily to be broken down into: <a href=\"http://www.tandfonline.com/doi/abs/10.1080/00926230590513401\" rel=\"noreferrer\">Are Orgasms in the Mind or the Body? Psychosocial Versus Physiological Correlates of Orgasmic Pleasure and Satisfaction</a>?</p>\n\n<p>There are not only those legends, fairy tales or \"reports\" from guru like figures or their followers. It seems at least not wholly uncommon to just engage your mind in very <a href=\"https://link.springer.com/article/10.1007%2FBF01542589?LI=true\" rel=\"noreferrer\">pleasurable thoughts and images to achieve something you desire</a>. </p>\n\n<p>So, that part of your question seems to have to be answered with a \"yes!\"\nAnd if it is not physical, then yes again, hm, by definition it has to be psychological. There <a href=\"https://www.youtube.com/watch?v=_GK6cct0Vjs\" rel=\"noreferrer\">has to be a reason</a>.</p>\n\n<p>But now, I have to be afraid, a manual for non-manpulation achievements is unknown to me. I guess you just have to use your own imagination.</p>\n\n<p>Have fun.</p>\n", "score": 5 } ]

[ "masturbation", "orgasm-climax" ]

[ { "answer_id": 21456, "body": "<p>I too was unable to find data on whether partial curfews are effective. I presume that the premise is that you keep the country running as people are able to work, and you can still collect some tax revenue whereas this is not possible with a full curfew. It seems a very double edged knife.</p>\n\n<p>Also, the people most likely to be out and socialising at night are the young people who are relatively immune to the fatal aspects of the disease. But they're also the ones who are most likely to be spreading it as well though current data suggests that in China it was the parents infecting the children and not the other way round.</p>\n", "score": 1 } ]

[ "covid-19", "disease-transmission", "infectious-diseases", "epidemiology", "health-policy" ]

[ { "answer_id": 23580, "body": "<p>Historically, vaccines eg 1955 polio vaccine had side effects due to manufacturing issues allowing live virus to appear in the vaccine in the Cutter company’s vaccine. In 1976, a swine flu vaccine was shown to have a risk of 1 in 100,000 of Guillaine-Barre Syndrome, a transient but serious neuromuscular syndrome. The 1998 rotavirus vaccine was shown to prevent serious life-threatening diarrheal illness in infants, but later studies suggested a risk of a rare form of bowel obstruction called intussusception. The recommendation for RotaShield vaccine was withdrawn.</p>\n\n<p>These side effects generally appeared within weeks, months or a few years of the vaccine administrative. </p>\n\n<p>Source:\n<a href=\"https://www.cdc.gov/vaccinesafety/concerns/concerns-history.html\" rel=\"noreferrer\">https://www.cdc.gov/vaccinesafety/concerns/concerns-history.html</a></p>\n\n<p>Over time this led to significant increase in safety oversight including the FDA VAERS (vaccine adverse event reporting system). Many long-term vaccine safety studies and monitoring systems have been built since then.</p>\n\n<p>For example, the Kaiser vaccine study center looked at hundreds of thousands of MMRV vaccine doses, for example. They found no long term side effects, but in this case the goal was to understand side effects relative to MMR &amp; V(aricella) vaccines given separately versus together.</p>\n\n<p>Source: \n<a href=\"https://www.webmd.com/children/vaccines/news/20150107/long-term-study-finds-measles-vaccines-safe\" rel=\"noreferrer\">https://www.webmd.com/children/vaccines/news/20150107/long-term-study-finds-measles-vaccines-safe</a></p>\n\n<p>Long term side effects can be a complication of any medical intervention, such as medications or devices also, as well as compared to the risk of untreated disease not prevented or not treated. As a result, scientists and clinicians weigh the risks, benefits and alternatives and ideally partner with patients, parents and caregivers in informed consent. Where information has not yet been gathered about long-term safety — or durability of the effect — large long term safety studies have generally been required, and are also possible to detect with such systems as the <a href=\"https://www.fda.gov/vaccines-blood-biologics/biologics-post-market-activities/cbers-sentinel-program\" rel=\"noreferrer\">FDA Sentinel system launched in 2008</a> and other similar safety systems available now (2020) that were not previously available. These systems permit longer range, larger population monitoring of both safety and effectiveness of vaccines and other medical treatments, and further detail by subgroups who may be at higher risk of side effects, or who may be at higher chance of benefiting from vaccines or medications.</p>\n", "score": 5 }, { "answer_id": 23107, "body": "<p>I think the unclarity in this question (and ironically that it's getting upvoted while the answers to it are getting downvoted) is that the question doesn't specify in its numbered premises that the side effect has to be <strong>commonly</strong> reported <em>but only after a long time</em>. A <em>very rare</em> side effect is statistically hard to find, so it's natural that it may take a long time to find some cases, even if it does show up fairly quickly in susceptible individual.</p>\n<p>The question then makes the following blurring/confusion: it goes from a trial in which effects were (not) found to a rollout which vastly expands the population/sample. The question is then misleadingly phrased as</p>\n<blockquote>\n<p>If not, what causes scientists to be so cautious about testing a new vaccine quickly?</p>\n</blockquote>\n<p>There's no reluctance to test a vaccine quickly enough in a small sample (e.g. phase II trials) if the vaccine &quot;passes the smell test&quot; in some preclinical trials etc. But e.g. phase II trials may not find all the rare side effects. The question probably wants to ask why does it take longer to get the vaccine <em>rolled out</em>, but it phrases that as &quot;scientists to be so cautious about <strong>testing</strong>&quot;. Basically the caution is about testing (with or without scare quotes) with a large sample all of a sudden, e.g. in an extreme case roll-out after successful pre-clinical trials. Increasing the sample size (as in phase III trials) gives more power to detect rarer side effects. In a <a href=\"https://uk.gsk.com/en-gb/research/trials-in-people/clinical-trial-phases/\" rel=\"nofollow noreferrer\">nutshell</a></p>\n<blockquote>\n<p>The first time a new treatment or vaccine is tested in humans, it will usually be given to a small group of healthy volunteers. [...]</p>\n<p>The principle objectives in Phase I are to:</p>\n<ul>\n<li>make sure that the new medicine presents no <strong>major</strong> safety issues\n[...]</li>\n</ul>\n<p>If Phase I is successful, approval will be sought for a trial involving a larger group of people. Phase II trials will usually (but not always) include patients who have the condition the potential medicine is targeting, and aim to establish: [...]</p>\n<ul>\n<li>effectiveness in preventing the condition (if the volunteer does not already have it)\n[...]</li>\n</ul>\n<p>Phase III</p>\n<p>If the results from Phase II are encouraging, we will seek to start a Phase III trial. This will be a much larger trial, often involving hundreds, possibly thousands of participants coming from a range of different countries.</p>\n<p>The principle objectives in Phase III are to:</p>\n<ul>\n<li><p>demonstrate the <strong>safety and effectiveness</strong> of the new medicine or vaccine in the typical patient likely to use it</p>\n</li>\n<li><p>identify side effects or reasons why the treatment should not be given to people with the condition in question (known as <strong>‘contraindications’</strong>)</p>\n</li>\n</ul>\n</blockquote>\n<p>Emphasis mine.</p>\n<p>Obviously when you increase the sample size even further (roll out) you may even find very rare side effects that were even missed in phase III. Sometimes <a href=\"http://www.genetherapynet.com/clinical-trial-phases.html\" rel=\"nofollow noreferrer\">there are</a> so-called phase IV studies</p>\n<blockquote>\n<p>Phase IV studies may be required by regulatory authorities or may be undertaken by the sponsoring company for competitive (finding a new market for the drug) or other reasons (for example, the drug may not have been tested for interactions with other drugs, or on certain population groups such as pregnant women, who are unlikely to subject themselves to trials).</p>\n<p><strong>The safety surveillance is designed to detect any rare or long-term adverse effects over a much larger patient population and longer time period than was possible during the Phase I-III clinical trials.</strong> Harmful effects discovered by Phase IV trials may result in a drug being no longer sold, or restricted to certain uses.</p>\n</blockquote>\n<p>So the last part of the question is based on (a lot) of misphrasing and/or bad (logical) premises, lumping everything (including roll out) under the word &quot;testing&quot;. The level of caution/reluctance is proportional with the size of the population being tested (on).</p>\n<hr />\n<p>So, how long can it take to figure it out if a vaccine gives <em>any</em> bad side effects? <a href=\"https://www.virology.ws/2015/09/10/why-do-we-still-use-sabin-poliovirus-vaccine/\" rel=\"nofollow noreferrer\">How about 20 years?</a> Because deciding if the observed side effects are caused by a vaccine or not is not actually trivial:</p>\n<blockquote>\n<p>all three of Sabin’s OPV strains were approved for use in the US, and in 1961-62 they replaced IPV for routine immunization against poliomyelitis.</p>\n<p>As soon as OPV was used in mass immunizations in the US, cases of vaccine-associated paralysis were described. Initially Sabin decried these findings, arguing that temporal association of paralysis with vaccine administration was not sufficient to implicate OPV. He suggested that the observed paralysis was caused by wild-type viruses, not his vaccine strains.</p>\n<p>A breakthrough in our understanding of vaccine-associated paralysis came in the early 1980s when the recently developed DNA sequencing methods were used to determine the nucleotide sequences of the genomes of the Sabin type 3 vaccine, the neurovirulent virus from which it was derived, and a virus isolated from a child who had developed paralysis after administration of OPV. The results enumerated for the first time the mutations that distinguish the Sabin vaccine from its neurovirulent parent. More importantly, the genome sequence of the vaccine-associated isolate proved that it was derived from the Sabin vaccine and was not a wild-type poliovirus.</p>\n<p>We now understand that every recipient of OPV excretes, within a few days, viruses that are more neurovirulent that the vaccine strains. This evolution occurs because during replication of the OPV strains in the human intestine, the viral genome undergoes mutation and recombination that eliminate the attenuating mutations that Sabin so carefully selected by passage in different hosts.</p>\n<p>From 1961 to 1989 there were an average of 9 cases (range, 1-25 cases) of vaccine-associated paralytic poliomyelitis (VAPP) in the United States, in vaccine recipients or their contacts, or 1 VAPP case per 2.9 million doses of OPV distributed (illustrated). Given this serious side effect, the use of OPV was evaluated several times by the Institute of Medicine, the Centers for Disease Control and Prevention, and the Advisory Committee on Immunization Practices. Each time it was decided that the risks associated with the use of OPV justified the cases of VAPP. It was believed that a switch to IPV would lead to outbreaks of poliomyelitis, because: OPV was better than IPV at protecting non-immunized recipients; the need to inject IPV would lead to reduced compliance; and IPV was known to induce less protective mucosal immunity than OPV.</p>\n</blockquote>\n<p>And yeah whether the benefits outweigh the risks of severe albeit seldom-encountered side effects is a balancing matter:</p>\n<blockquote>\n<p>After the WHO began its poliovirus eradication initiative in 1988, the risk of poliovirus importation into the US slowly decreased until it became very difficult to justify routine use of OPV. In 1996 the Advisory Committee on Immunization Practices decided that the US would transition to IPV and by 2000 IPV had replaced OPV for the routine prevention of poliomyelitis. As a consequence VAPP has been eliminated from the US.</p>\n</blockquote>\n<p>Yes, yes, I can see the objections already that with the current state of biology/medicine we'd figure it out faster now. YMMV, i.e. it's down to &quot;expert opinion&quot; whether we could completely avoid a repeat of VAPP.</p>\n", "score": 4 }, { "answer_id": 26372, "body": "<blockquote>\n<p>Live attenuated varicella vaccines do contain actual varicella zoster virus (Oka strain), which can establish infection in hosts and undergo latency like other herpesviruses including the unattenuated virus. As a result they can very rarely cause shingles or meningitis years after the receipt of the vaccine. This is a consequence of 2 things: the use of a live vaccine, and the ability of herpesviruses like varicella to undergo latency</p>\n</blockquote>\n<p><a href=\"https://edwardnirenberg.medium.com/long-term-effects-of-covid-19-vaccines-should-you-be-worried-c3c3a547b565\" rel=\"nofollow noreferrer\">Long-Term Effects of COVID-19 Vaccines: Should You Be Worried?</a></p>\n", "score": 4 } ]

[ "covid-19", "side-effects", "vaccination", "history" ]

[ { "answer_id": 26007, "body": "<p>The full details are quite complicated, but this nomenclature defines SARS-CoV-2 variants by a lineage depending on which variant they are descended from.</p>\n<blockquote>\n<p><a href=\"https://www.biorxiv.org/content/10.1101/2020.04.17.046086v1.full.pdf\" rel=\"noreferrer\">A dynamic nomenclature proposal for SARS-CoV-2 to assist genomic\nepidemiology</a></p>\n<p>Andrew Rambaut, Edward C. Holmes, Verity Hill, Áine O’Toole, JT McCrone, Chris Ruis, Louis du Plessis, Oliver G. Pybus</p>\n</blockquote>\n<p>This article can be found from <a href=\"https://pangolin.cog-uk.io/\" rel=\"noreferrer\">Pangolin</a> (<strong>P</strong>hylogenetic <strong>A</strong>ssignment of <strong>N</strong>amed <strong>G</strong>lobal <strong>O</strong>utbreak <strong>LIN</strong>eages, in case you were wondering!).</p>\n<p>which uses the above system in it's software.</p>\n<p>The concept is not unique however, for example <a href=\"https://nextstrain.org/\" rel=\"noreferrer\">NextStrain</a> use the following to name their COVID-19 clades.</p>\n<blockquote>\n<p><a href=\"https://docs.nextstrain.org/en/latest/tutorials/SARS-CoV-2/steps/naming_clades.html\" rel=\"noreferrer\">https://docs.nextstrain.org/en/latest/tutorials/SARS-CoV-2/steps/naming_clades.html</a></p>\n</blockquote>\n", "score": 9 }, { "answer_id": 26008, "body": "<p>Alas (Pangoling/COG-UK) base letterings don't stand for location. And neither do the numbers following them stand for directly identifiable mutations except for the &quot;with E484K&quot; designators. Those directly stand for specific mutations relative to the first-identified/original variant. As Wikipedia explains</p>\n<blockquote>\n<p>The name of the mutation, E484K, refers to an exchange whereby the glutamic acid (E) is replaced by lysine (K) at position 484. It is nicknamed &quot;Eeek&quot;.</p>\n</blockquote>\n<p>As for designations like B.1.1.7 those refer indirectly to mutations. The competing designation for that from Nextstrain <a href=\"https://en.wikipedia.org/wiki/Lineage_B.1.1.7\" rel=\"nofollow noreferrer\">is</a> 20I/501Y.V1 (formerly 20B/501Y.V1).</p>\n<p><a href=\"https://nextstrain.org/\" rel=\"nofollow noreferrer\">Nextstrain</a> is a US-Swiss endeavor, while Pangolin/COG-UK <a href=\"https://en.wikipedia.org/wiki/COVID-19_Genomics_UK_Consortium#Developments\" rel=\"nofollow noreferrer\">is</a> (somewhat evidently) UK based.</p>\n<p>As for the Pangolin naming, they started with two letter (A and B) but the first letter actually changes when the nesting gets too deep:</p>\n<blockquote>\n<p>We propose that major lineage labels begin with a letter. At the root of the phylogeny of SARS-CoV-2 are two lineages that we simply denote as lineages A and B. The earliest lineage A viruses, such as Wuhan/WH04/2020 (EPI_ISL_406801), sampled on 2020-01-05, share two nucleotides (positions 8782 in ORF1ab and 28144 in ORF8) with the closest known bat virus (RaTG13). Different nucleotides are present at those sites in viruses assigned to lineage B, of which Wuhan-Hu-1 (Genbank accession MN908947) sampled on 2019-12-26 is an early representative. Hence, although viruses from lineage B were sequenced and published first (Wu et al. 2020; Zhu et al. 2020; Lu et al. 2020), it is likely (based on current data) that lineage A viruses form the root of the SARS-CoV-2 pandemic phylogeny. At the time of writing, viruses from both lineages A and B are still circulating in many countries around the world [...]</p>\n<p>e then defined\nfurther SARS-CoV-2 lineages, each of which descends from either lineage A or B and is\nassigned a numerical value (e.g. lineage A.1, or lineage B.2). Lineage designations were made\nusing the following set of conditions: [...]</p>\n<p>Each descendent lineage should show phylogenetic evidence of emergence from an\nancestral lineage into another geographically distinct population, implying substantial\nonward transmission in that population. In the case of a rapidly expanding global lineage\nthe recipient “population” may comprise multiple countries. In the case of large and\npopulous countries it may represent a new region or province. [...]</p>\n<p>The iterative procedure in step II can proceed for a maximum of 3 sublevels (e.g. A.1.1.1) after which new descendent lineages are given a letter (in English alphabetical sequence from C - so A.1.1.1.1 would become C.1 and A.1.1.1.2 would become C.2.</p>\n</blockquote>\n<p>At the time that paper was written B.1.1.7 had not yet been identified, but its ancestors were:</p>\n<p><a href=\"https://i.stack.imgur.com/tnv0J.png\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/tnv0J.png\" alt=\"enter image description here\" /></a></p>\n<p>As you can see B.1.1 had spread to the UK, so the &quot;Kent&quot; variant discovered in late 2020 was assigned under B.1.1 for those reasons.</p>\n<p>Now the <a href=\"https://en.wikipedia.org/wiki/Lineage_P.1\" rel=\"nofollow noreferrer\">lineage P.1</a> for example</p>\n<blockquote>\n<p>has also been called 'B.1.1.28.1', although strictly only three sublevels are permitted in the PANGO Lineage system of nomenclature, hence the designation 'P.1'.</p>\n</blockquote>\n", "score": 6 } ]

[ "covid-19" ]

[ { "answer_id": 31194, "body": "<h4>Your explanation numbered 1 is correct.</h4>\n<h5>The control line indicates that the antibodies required to detect the SARS-CoV-2 (the virus that causes COVID-19) particles have reached that location on the test strip.</h5>\n<p>Each product is slightly different, but the <a href=\"https://b16mcf0yrs1xyw6j2yl5vo18-wpengine.netdna-ssl.com/wp-content/uploads/2021/09/Rapid-Response-COVID-19-Antigen-Rapid-Test-Device-Insert-V4.5.pdf\" rel=\"noreferrer\">Rapid Response package insert</a> notes:</p>\n<blockquote>\n<p>Anti-SARS-CoV-2 antibodies are immobilized on\nthe test region of the nitrocellulose membrane. Anti-SARS-CoV-2 antibodies conjugated to coloured\nparticles are immobilized on the conjugated pad. A sample is added to the extraction buffer which is\noptimized to release the SARS-CoV-2 antigens from specimen.\nDuring testing, the extracted antigens bind to anti-SARS-CoV-2 antibodies conjugated to coloured\nparticles. As the specimen migrates along the strip by capillary action and interacts with reagents on the\nmembrane, the complex will be captured by the anti-SARS-CoV-2 antibodies at the test region. Excess\ncoloured particles are captured at the internal control zone.</p>\n</blockquote>\n<p>This image <a href=\"https://en.wikipedia.org/wiki/Dipstick#/media/File:Diagnostic_Medical_Dipstick.png\" rel=\"noreferrer\">I made for Wikipedia many years ago</a> explains how this works:\n<a href=\"https://i.stack.imgur.com/fGemW.jpg\" rel=\"noreferrer\"><img src=\"https://i.stack.imgur.com/fGemW.jpg\" alt=\"enter image description here\" /></a></p>\n<p>In this case, the SARS-CoV-2 nucleoprotein antigens are the green dots. Antibodies specific for the nucleoprotein antigens are attached to colorful gold dots. When you place the a sample with virus on the test strip, the antibodies with the gold bind to the virus. As it moves up the strip by capillary action, another part of the virus binds to the antibodies pictured here in black. The increased local concentration of gold particles is visible on the strip.</p>\n<p>Antibodies with gold attached that are not captured by the black region reach the blue region, where the <em>antibodies themselves</em> are bound. Thus, the control line only ensures that antibodies from the space where you drop the test solution have reached a location further away than the SARS-CoV-2 specific region. It does not ensure any particular composition of the sample.</p>\n<p>The package insert describes this:</p>\n<blockquote>\n<p>A coloured band at the control region serves as a\nprocedural control, indicating that the proper volume of specimen has been added and membrane\nwicking is working.</p>\n</blockquote>\n", "score": 14 } ]

[ "covid-19", "test" ]

[ { "answer_id": 275, "body": "<p>There are many essential oils and each can work differently and on different micro-organisms. They could affect the skin and mucous membranes in ways that are valuable or harmful.</p>\n\n<p>For example steam-distilled <strong><a href=\"http://en.wikipedia.org/wiki/Eucalyptus_oil\" rel=\"noreferrer\">eucalyptus oil</a></strong> is used as a primary cleaning/disinfecting agent added to soaped mop and countertop cleaning solutions, however there are hundreds of species of eucalyptus and dozens are used as sources of essential oils, so products of different species differ greatly in characteristics and effects and also the products of the very same tree can vary grossly^{<a href=\"http://en.wikipedia.org/wiki/Essential_oil#Eucalyptus_oil\" rel=\"noreferrer\">wiki</a>}.</p>\n\n<p>Some other <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/15824699\" rel=\"noreferrer\">studies</a> show that <strong><a href=\"http://en.wikipedia.org/wiki/Tea_tree_oil#Medical_use\" rel=\"noreferrer\">tea tree oil</a></strong> is capable of killing <a href=\"http://en.wikipedia.org/wiki/MRSA\" rel=\"noreferrer\">MRSA</a> in a laboratory setting, however there is insufficient evidence. A 2012 review by the <a href=\"http://en.wikipedia.org/wiki/NIH\" rel=\"noreferrer\">NIH</a> rates Tea tree oil as \"possibly effective\" for: treating acne, fungal toenail infection or symptoms of athlete's foot. Which indicates its antibacterial properties only against certain infection.</p>\n\n<p>On the other hand some other essential oils generally should not be applied directly to the skin in their undiluted or \"neat\" form, as can cause potential danger such as severe irritation, provoke an allergic reaction and, over time, prove <a href=\"http://en.wikipedia.org/wiki/Hepatotoxic\" rel=\"noreferrer\">hepatotoxic</a>. Some other, including many of the citrus peel oils, are photosensitizers, increasing the skin's vulnerability to sunlight.</p>\n\n<p>In summary, <strong>non-therapeutic grade essential oils are never recommended for topical or internal use</strong> (including animals, which could cause extreme hepatotoxicity and dermal toxicity), unless specific essential oil has pharmaceutical properties and you know they're safe for use, however they're not good alternative to alcohol-based disinfectant products.</p>\n", "score": 6 } ]

[ "bacteria", "essential-oil" ]

[ { "answer_id": 269, "body": "<p>When you say</p>\n\n<blockquote>\n <p>In one of my most recent blood panels (for a medical study group) came back with HbA1c levels that indicated I was prediabetic, but again, follow up studies were negative.</p>\n</blockquote>\n\n<p>What was the HbA1C level, and what follow-up study was negative?</p>\n\n<p>In the <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/17614026\" rel=\"nofollow noreferrer\">Lippi study</a>, HbA1c values between sedentary individuals and professional cyclists were 5.2 +/- 0.3% versus 5.4 +/- 0.2% respectively. That's really fairly marginal. Normal levels are below 5.7 percent. </p>\n\n<p>HbA1C levels are indeed valid concerns for athletes, as valid as for anyone else. The risk of heart disease, however, is lower in this group <strong>in spite</strong> of the elevated A1C because of fitness levels.</p>\n\n<p>Glucose molecules don't respect elite cyclists more than couch potatoes. End-organ damage (through glycosylation) is the primary concern here. Your kidneys and eyes (among other things) aren't helped by your exercise, but they are damaged by diabetes.</p>\n\n<p>_{<a href=\"http://www.mayoclinic.org/diseases-conditions/type-2-diabetes/basics/tests-diagnosis/con-20031902\" rel=\"nofollow noreferrer\">Type 2 diabetes Mayo Clinic</a>} </p>\n", "score": 8 }, { "answer_id": 3366, "body": "<p>Yes, high blood sugar levels can cause damage in the body---but it is SUSTAINED high blood sugar levels that are dangerous. Here is another interesting article on A1c and athletes: <a href=\"http://fitafter40vancouver.blogspot.com/2010/12/hba1c-and-athletes.html\" rel=\"nofollow\">http://fitafter40vancouver.blogspot.com/2010/12/hba1c-and-athletes.html</a></p>\n\n<p>Athletes may have short bursts of higher glucose in their blood stream after exercise and not prolonged high levels.</p>\n\n<p>I, too, am an endurance athlete (ultra-marathon runner) who tends to have borderline high A1c results. My last results was 5.7.</p>\n", "score": 3 }, { "answer_id": 18693, "body": "<p>The expert opinion of the study author Lippi appears now to be just the opposite from the possible conclusion drawn in the question:</p>\n\n<blockquote>\n <p>Hyperglycemia has been the leading diagnostic criterion for diagnosing diabetes since the development of blood glucose assays 100 years ago (25). The ADA has recently advocated using HbA1c for the diagnosis of diabetes and the identification of those at high-risk of developing diabetes. However, at present no other organizations or scientific societies, including the IFCC and the European Federation of Clinical Chemistry (EFCC), have officially endorsed this recommendation. Although a clinical role might exist for screening (i.e., by using a HbA1c cut-off between 6.5% and 7.0%), it seems premature to conclude that HbA1c measurement, at least alone, might be sufficiently accurate to allow wide-spread implementation for the diagnosis of diabetes. At present, its diagnostic role should be limited to those patients with no comorbidities or patho-physiological conditions that might reduce the diagnostic efficiency of this test (Table 2). Whether the old dogma of HbA1c testing for monitoring overall glycemic exposure will translate into a valuable tool for the diagnosis of diabetes, only the future and analysis of its cost effectiveness will determine this role. The article from the GLAD Working Group published in this issue of Clinical Chemistry and Laboratory Medicine, which is aimed at promoting a coordinated plan for implementing the standardization of HbA1c measurement in Italy, represents a foremost contribution for further investigations on this topic.</p>\n \n <p>Giuseppe Lippi &amp; Giovanni Targher: \"<a href=\"https://www.degruyter.com/view/j/cclm.2010.48.issue-5/cclm.2010.144/cclm.2010.144.xml\" rel=\"nofollow noreferrer\">Glycated hemoglobin (HbA1c): old dogmas, a new perspective?</a>\", Clin Chem Lab Med 2010;48(5):609–614. DOI:10.1515/CCLM.2010.144 </p>\n</blockquote>\n\n<p>And very recently</p>\n\n<blockquote>\n <p>The results of our study, which is based on a larger sample size than previous investigations, show that the concentration of plasma glucose is significantly decreased from 3 to 24hours after endurance running. Unlike plasma glucose, <strong>HbA1c values were almost unchanged up to 24hours after a half-marathon run, thus suggesting that this parameter <em>may be more reliable</em> than FPG or RPG for diagnosing diabetes in physically active subjects, regularly engaged in recreational or competitive endurance activity.</strong></p>\n \n <p>Giuseppe Lippi et al.: \"<a href=\"https://www.ncbi.nlm.nih.gov/pubmed/29884709\" rel=\"nofollow noreferrer\">Challenges of diagnosing diabetes in endurance athletes</a>\", J Clin Pathol 2018;71:944–945. doi:10.1136/jclinpath-2018-205043</p>\n</blockquote>\n", "score": 1 } ]

[ "blood-tests", "diabetes", "glycated-hemoglobin-hba1c" ]

[ { "answer_id": 297, "body": "<p>In most cases, swimming is good exercise. Light swimming is also a therapy for people with joint and back pain. The breaststroke is not usually the recommended stroke for therapy because, if done incorrectly, it can be harmful. </p>\n\n<p>Because you have to keep bringing your head up to breath, the joints in your upper back and neck get extended, and have to deal with a lot of stress from repetitive movement. This can cause a lot pain, especially to those who have experienced back problems before. Having your head up and looking forward can also cause your hips to drop, which puts extra strain on the lower back. This can lead to extra back problems, such as <a href=\"http://medical-dictionary.thefreedictionary.com/hyperextension\" rel=\"nofollow\">hyperextension</a>.</p>\n\n<p>There are some tips to help you avoid back pain when swimming the backstroke.</p>\n\n<ul>\n<li><p>Keep your head underwater as long as possible; wearing goggles helps with this</p></li>\n<li><p>Try to keep your head looking down instead of towards the end of the pool</p></li>\n<li><p>Get swimming lessons - swimming instructors can be found everywhere, and if you really want to swim the breaststroke without any pain, then it would be a good thing to considers</p></li>\n</ul>\n\n<p>Overall, there is some middle ground between the things you have heard, but the second thing that you mentioned is probably more accurate. Done correctly, you will be fine, but done incorrectly, you could injure your back.</p>\n\n<hr>\n\n<p>^{<a href=\"http://www.spine-health.com/conditions/sports-and-spine-injuries/swimming-and-back-pain\" rel=\"nofollow\">Swimming and Back Pain</a>}</p>\n", "score": 5 }, { "answer_id": 376, "body": "<p>In general hydrotherapy is advised and can improve mobility and help relieve discomford and promote recovery from injury.</p>\n\n<p>If you've neck or back problems, you may find that breaststroke aggravates your condition rather than improves it, but it could simply be down to poor technique. ^{<a href=\"http://www.nhs.uk/ipgmedia/National/Arthritis%20Research%20UK/assets/Keepmoving.pdf\" rel=\"nofollow\">Keep moving</a>}</p>\n\n<hr>\n\n<p>In <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953356\" rel=\"nofollow\">Prevention and Treatment of Swimmer's Shoulder (2006)</a> study we can read:</p>\n\n<blockquote>\n <p>Movement at the shoulder during breaststroke can vary, with more motion occurring below the surface of the water than any other stroke. Like the butterfly, the arms are moved simultaneously through a motion that starts in full flexion with internal rotation. However, the elbows remain flexed during the pull-through until the humerus is fully adducted and brought into horizontal adduction with forearms touching each other. Unlike the other strokes, the hands never move below the hips so the tensile forces on the rotator cuff that occurs during the other strokes at the end of pull-thorough does not occur during breaststroke¹.</p>\n</blockquote>\n\n<p>References:</p>\n\n<ul>\n<li>[1]: Shapiro C. Swimming. In Shamus E, Shamus J, editors. (eds)Sports injury prevention and rehabilitation. New York: McGraw-Hill;2001:103–154</li>\n</ul>\n", "score": 1 } ]

[ "sports", "swimming", "back" ]

[ { "answer_id": 251, "body": "<p>Currently I am not aware of any scientifically based recommendations for levels of healthy body fat. There are empirical observations and actuarial tables/considerations, but there hasn't been a definitive \"For a 30 year old Caucasian male, 8-15% body fat is ideal for health\" studies out yet.</p>\n\n<p>There was a study in 2000 that was published in the <a href=\"http://ajcn.nutrition.org/content/72/3/694.long\" rel=\"noreferrer\">American Journal of Clinical Nutrition</a> that attempted to lay some groundwork for this kind of evaluation, and they came up with some interesting formulae for body fat assessment, but it was left as very open ended and needing much more study.</p>\n\n<p>There is a chart available through the American Council on Exercise (ACE) that shows levels of fat for various categories of men and women, but it makes no distinction on age, merely on activity level.</p>\n\n<p><img src=\"https://i.stack.imgur.com/MSjAr.jpg\" alt=\"enter image description here\"></p>\n\n<p>Another pair of charts from Accufitness (Makers of body fat calipers) I like better, as it accounts for both age and sex, but makes no allowances for activity level.</p>\n\n<p><img src=\"https://i.stack.imgur.com/t9KNk.jpg\" alt=\"enter image description here\">\n<img src=\"https://i.stack.imgur.com/mzJpz.jpg\" alt=\"enter image description here\"></p>\n\n<p>If you look at BMI charts, anything below 18.5 is considered unhealthy, and anything over 25-30 (depending on chart) is trending towards the obese range. These are more statistical/actuarial tables than anything, however and have been around (largely unchanged) since inception in the early/mid 1800's.</p>\n\n<p>As far as the measurement, there are three different types of fat, subcutaneous (under the skin), visceral (Around body organs) and intramuscular (In the muscles, like marbling on a steak). Bioelectric impedance (Such as the scale you mention) work by passing a low electric current through the body and measuring the resistance. These can have a +/- accuracy range of 3-10% depending on the model, and can be affected by hydration, time of day, wet skin, and other factors.</p>\n\n<p>Skin calipers done by an experienced practitioner can have a variance as low as 3%, underwater weighing (Again done properly) can get below 3%, and the gold standard is a DXA scan that measures everything from bone density to total fat.</p>\n\n<p>So far everyone agrees that too low or too high a weight is bad and carries risk of injury/illness/disease, but we haven't agreed yet on what is good for which population cohort.</p>\n", "score": 10 } ]

[ "weight", "body-fat", "quantified-self", "measurement" ]

[ { "answer_id": 598, "body": "<p>Scientific research has been conducted on the absorption of nutrients provided by both food groups when combined. From a nutritional point of view, the absorption of both <code>calcium</code> and <code>iron</code> <strong>could</strong> have the former prevent the absorption of the latter. </p>\n\n<blockquote>\n <p>In single-meal human absorption studies, both haem- and non-haem-Fe absorption was inhibited by Ca supplements and by dairy products, the effect depending on the simultaneous presence of Ca and Fe in the lumen of the upper small intestine and also occurring when Ca and Fe were given in the fasting state. The quantitative effect, although dose dependent, was modified by the form in which Ca was administered and by other dietary constituents (such as phosphate, phytate and ascorbic acid) known to affect Fe bioavailability.</p>\n</blockquote>\n\n<p>and</p>\n\n<blockquote>\n <p>The results of most multiple-meal human studies suggest that Ca supplementation will have only a small effect on Fe absorption unless habitual Ca consumption is very low. Outcome analyses showed that Ca supplements had no effect on Fe status in infants fed Fe-fortified formula, lactating women, adolescent girls and adult men and women. However it should be noted that the subjects studied had adequate intakes of bioavailable Fe and, except in one study, had relatively high habitual Ca intakes.</p>\n</blockquote>\n\n<p>See: <a href=\"http://www.ncbi.nlm.nih.gov/pubmed/19087437\" rel=\"nofollow\">http://www.ncbi.nlm.nih.gov/pubmed/19087437</a></p>\n", "score": 1 } ]

[ "nutrition" ]

[ { "answer_id": 3893, "body": "<p>I would recommend keeping those old results around for at least a few years, since it isn't usually a big problem to do so. Having old records around to compare results to <em>might</em> be beneficial. </p>\n\n<p>In many countries, medical professionals or labs might be required by law to keep your records around and hand those results over to you or any doctor you authorize for a number of years. For example, here in Germany, they need to keep normal laboratory results for ten years, for some other items this can be up to 30 years. Similar laws exist <a href=\"http://m.bma.org.uk/support-at-work/ethics/retention-of-health-records\" rel=\"noreferrer\">in the UK</a> and <a href=\"https://www.rmf.harvard.edu/Clinician-Resources/FAQ-Category/Medical-Records\" rel=\"noreferrer\">the US</a> (where the exact legislation is state-specific, as far as I can tell). Since it can be a hassle getting them when you, for example, move, I'd also keep copies myself, though. </p>\n\n<p>The point of keeping old non-significant test results around can be:</p>\n\n<ul>\n<li>to see that a significant result later is a new addition. As such, if a later test shows elevated blood sugar / hemoglobin, a doctor at least has an estimate of when this problem started. </li>\n<li>to reveal a trend, for example decreasing Vitamin D levels making supplementation desirable, or slowly increasing TSH levels pointing to a beginning hypothyroidism. More tests can then be ordered if necessary. </li>\n<li>since \"normal ranges\" are just normal for a population, and not necessarily for you (see <a href=\"http://ucsdlabmed.wikidot.com/chapter-1\" rel=\"noreferrer\">How reference ranges are established</a>), even a value that is marked as non-significant might not actually be normal for you. Having many values from the past can show an outlier that would be within the reference range, but is a significant result for you. </li>\n</ul>\n\n<p>One example where a trend within \"normal\" levels could be of diagnostic value is hemoglobin:</p>\n\n<blockquote>\n <p>Paying close attention to routine blood test results can be an effective screening system for colon cancer which, when diagnosed early enough, can be treated effectively. A new study shows that most patients with colon cancer have a history of consistently declining hemoglobin levels up to four years before being diagnosed with the disease</p>\n</blockquote>\n\n<p><a href=\"http://www.sciencedaily.com/releases/2010/08/100803152837.htm\" rel=\"noreferrer\">Is your hemoglobin 'trending'? Routine blood tests may provide early warning for colorectal cancer</a></p>\n\n<p>Since for most people this would just amount to asking for a copy at a doctor's visit and then putting it in a folder when coming home, keeping the records doesn't appear too difficult to not do it. </p>\n", "score": 5 }, { "answer_id": 18160, "body": "<h2>Keep them throughout your life and bequeath them to your children.</h2>\n\n<p>This answer is not as extreme as it sounds, since it's a cost/benefit analysis.</p>\n\n<h3>The cost side</h3>\n\n<p>When you get blood test results - if it's in writing, scan them (these days you can even do this with your phone and apps like camScanner) and save them as a file per page. If you get them online - save the results. At this point, the cost of keeping them is quite negligible - a few megabytes over your entire lifetime. There's extra cost in <em>consolidating</em> them, i.e. putting everything into a nice table of result by specific test and date of test, but you can avoid that unless/until you actually need to.</p>\n\n<h3>The benefit side</h3>\n\n<blockquote>\n <p>I expect any doctor interested in blood test results would just order a new test. </p>\n</blockquote>\n\n<p>Maybe so, maybe no. If a doctor is considering whether to administer some treatment, they could well use older blood tests - because those could indicate situations you <em>might</em> get into, or conditions you might be prone to. Plus, old blood test results are available immediately (assuming you kept them available), while new blood tests require some time. In my personal experience (with the Maccabi HMO in Israel), some blood tests are only guaranteed to return results after 6 days.</p>\n\n<blockquote>\n <p>Is there any real chance they would want to look at old results, too?</p>\n</blockquote>\n\n<p>Sure there is:</p>\n\n<ul>\n<li>To examine changes over time.</li>\n<li>To relate your result ranges when you're healthy to results while you're experiencing some ailment.</li>\n<li>To relate your results to those of your siblings, children or other family members.</li>\n<li>For statistical research involving many people (if you agree to participate in it).</li>\n</ul>\n\n<p>_{<em>Caveat</em>: I'm not a Doctor. Or rather, not a Medical Doctor.}</p>\n", "score": 3 } ]

[ "blood-tests", "medical-records" ]

[ { "answer_id": 691, "body": "<p>Most of the time it is critically important to realize that sleep deprivation is very often due to unrecognized sleep disorders. After a typical night's sleep, you may not feel restored and refreshed and be sleepy during the day, but be totally unaware that you are sleep-deprived or have a sleep disorder. You might tend to think, \"It's just the stress of work or the kids,\" or you might have \"always felt this way\" and had no idea that you should feel differently. This lack of awareness compounds the consequences, because so many people remain undiagnosed for years.<br> <br> Now speaking about the disorders or consequences that the sleep deprivation can cause are. <br></p>\n\n<ul>\n<li><h1>Decreased Performance and Alertness:</h1> Sleep deprivation induces significant reductions in performance and alertness. Reducing your nighttime sleep by as little as one and a half hours for just one night could result in a reduction of daytime alertness by as much as 32%.<br><br>\n</li>\n<li><h1>Memory and Cognitive Impairment:</h1> Decreased alertness and excessive daytime sleepiness impair your memory and your cognitive ability -- your ability to think and process information.<br><br>\n\n</li>\n<li><h1>Automobile Injury:</h1> The National Highway Traffic Safety Administration (NHTSA) estimates conservatively that each year drowsy driving is responsible for at least 100,000 automobile crashes, 71,000 injuries, and 1,550 fatalities.<br><br>\n<li><h1>Increase Stroke risk:</h1>Even without the typical risk factors, like being overweight or having a family history, short sleep can up your risk for stroke, according to 2012 research. Adults who regularly slept fewer than six hours a night had four times the risk of stroke symptoms,<br><br>\n</li>\n<li><h1>Fuel Memory Loss:</h1>You probably know that on the days when you are most tired, you're forgetful and unfocused -- but sleep deprivation can lead to permanent cognitive issues. The less we sleep, the less we benefit from the memory-storing properties of sleep. But additionally, a lack of sleep can cause \"brain deterioration,\" according to a 2013 study, which may at least in part explain memory loss in seniors.<br><br>\n</li>\n</ul>\n\n<p>see also:</p>\n\n<ol>\n<li><a href=\"http://www.webmd.com/sleep-disorders/features/important-sleep-habits\" rel=\"nofollow\">Important sleep habits:webMd.com</a></li>\n<li><a href=\"http://www.huffingtonpost.com/2014/09/18/scary-sleep-deprivation-effects_n_2807026.html?ir=India\" rel=\"nofollow\">8 Scary Side Effects Of Sleep Deprivation</a></li>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/books/NBK19961/\" rel=\"nofollow\">Extent and Health Consequences of Chronic Sleep Loss and Sleep\nDisorders</a></li>\n<li><a href=\"http://en.wikipedia.org/wiki/Sleep_deprivation\" rel=\"nofollow\">Sleep Deprivation: Wikipedia</a></li>\n</ol>\n", "score": 5 } ]

[ "sleep", "brain" ]

[ { "answer_id": 613, "body": "<p>There have been no additional reports in the <em>Morbidity and Mortality Weekly Report</em>, which was where your original article points to regarding the efficacy of the flu vaccine.</p>\n\n<p>However, the <a href=\"http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6408a2.htm?s_cid=mm6408a2_w\" rel=\"noreferrer\">most recent update</a> on influenza activity within the United States, which was about a month later than your report, does not suggest there has been any mid-season change in the dominant circulating strains, so the early estimates are likely in the same area.</p>\n\n<p>The one thing that may change this is that a larger number of last season cases of influenza are typically caused by influenza B viruses, as shown in this figure below:</p>\n\n<p><img src=\"https://i.stack.imgur.com/H10nw.gif\" alt=\"enter image description here\"></p>\n\n<p>The low effectiveness of the vaccine against the dominant circulating A strains does not necessarily imply a similarly low effectiveness against the later B strains, especially as B strains <a href=\"http://www.cdc.gov/flu/weekly/weeklyarchives2014-2015/images/image141.gif\" rel=\"noreferrer\">appear to be somewhat more stable</a>.</p>\n", "score": 8 } ]

[ "vaccination", "infection", "influenza" ]

[ { "answer_id": 603, "body": "<p><a href=\"https://health.stackexchange.com/a/592/165\">Another answer</a> did a great job laying out some of the difficulties plaguing research on this topic. Observational data in the area are (hopelessly?) confounded. I would like to point out two alternative lines of research that may leave the reader with some hope that we’ll eventually have a good answer to this question.</p>\n\n<ol>\n<li><p><strong>Surrogate markers</strong>: A major difficulty with research in this area is that it’s not practical to randomize an adequate number of people to alcohol vs no alcohol¹ for a long enough period of time to see statistically significant differences in outcomes like heart attacks, strokes, and death. However, in many areas &mdash; most prominently cardiovascular disease &mdash; researchers have used <a href=\"http://circ.ahajournals.org/content/109/25_suppl_1/IV-20.long\" rel=\"nofollow noreferrer\">surrogate markers</a> that tend to evolve more quickly and have been shown to correlate with the <em>real</em> endpoint that we are interested in. This approach allows us to:</p>\n\n<ul>\n<li>Acquire <strong>randomized</strong> data due to the shorter duration of study required, avoiding all of the mess of observational confounds or; </li>\n<li>(Less optimal but still something): use observational methods but analyze endpoints that are less likely to be confounded. </li>\n</ul>\n\n<p>I include two papers that review interventional data suggesting a benefit of alcohol on surrogate endpoints: </p>\n\n<p><a href=\"http://www.bmj.com/content/342/bmj.d636\" rel=\"nofollow noreferrer\">Effect of alcohol consumption on biological markers associated with risk of coronary heart disease: systematic review and meta-analysis of interventional studies.</a>²</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pubmed/25805864\" rel=\"nofollow noreferrer\">The Effect of Alcohol Consumption on Insulin Sensitivity and Glycemic Status: A Systematic Review and Meta-analysis of Intervention Studies.</a>³ </p>\n\n<p>Despite the feasibility benefits of surrogate endpoints, these <a href=\"http://circ.ahajournals.org/content/109/25_suppl_1/IV-20.long\" rel=\"nofollow noreferrer\">“markers of malign” carry certain caveats</a> and can not be regarded as providing a definitive answer about whether alcohol should be recommended to reduce the risk of chronic diseases.</p></li>\n<li><p><strong>Randomized, double-blinded, placebo-controlled trials</strong> (with real endpoints) <strong>in the making</strong>: \nThis is what we want. There is an <a href=\"http://grants.nih.gov/grants/funding/ac_search_results.htm?text_curr=U34&amp;Search_Type=Activity\" rel=\"nofollow noreferrer\">NIH U34</a> active for planning a multi-center <a href=\"https://www.collectiveip.com/grants/NIH:8757476\" rel=\"nofollow noreferrer\">long-term randomized controlled trial to investigate the effect of alcohol on the development of chronic diseases.</a> You may be wondering how you randomize and blind people to alcohol consumption. Although the methodology of that large trial is not yet published (to my knowledge), the Mukamal lab has a history of <a href=\"https://www.clinicaltrials.gov/ct2/show/NCT00786279?term=mukamal&amp;rank=1\" rel=\"nofollow noreferrer\">putting tasteless grain alcohol in Crystal Light</a> (see also, <a href=\"http://blogs.wsj.com/health/2009/05/06/grain-alcohol-and-crystal-light-its-for-science/\" rel=\"nofollow noreferrer\">WallStreet Journal blog piece</a>). That feasibility study was completed; I look forward to updating this answer in a few years when the data from the large RCT are published.</p></li>\n</ol>\n\n<hr>\n\n<p>_{\n1. Note that although resveratrol, a component of red wine, has been publicized as the possibly beneficial agent (partly because it can be put in supplements and sold...), many researchers in the field consider ethanol itself to be of more interest. The data in this answer all investigate ethanol rather than other components of wine or beer, several of which may carry additional benefits.\n} </p>\n\n<p>_{\n2. Brien, SE et al. BMJ.2011;342:d636\n} </p>\n\n<p>_{\n3. Schrieks IC et al. 2015 Apr;38(4):723-732.\n}</p>\n", "score": 11 }, { "answer_id": 592, "body": "<p>With many of the studies on alcohol consumption and heart health, they look at people who drink moderately, generally a glass of red wine (resveratrol). Some researchers hypothesis that it is the resveratrol that leads to reduce atherosclerosis. This thought comes from the French paradox or the resveratrol paradox [<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3398412/\">1</a>]. The paradox is why do the French live so long with a diet high in saturated fats while they also consume a lot of red wine (since alcohol is a poison).</p>\n\n<p>However, correlation doesn't equal causation, i.e, there can be third a factor. Researchers from Harvard found that being stressed and unhappy can have lasting negative effects on the body [<a href=\"http://www.hsph.harvard.edu/news/magazine/happiness-stress-heart-disease/\">2</a>]:</p>\n\n<blockquote>\n <p>A vast scientific literature has detailed how negative emotions harm the body. Serious, sustained stress or fear can alter biological systems in a way that, over time, adds up to “wear and tear” and, eventually, illnesses such as heart disease, stroke, and diabetes. Chronic anger and anxiety can disrupt cardiac function by changing the heart’s electrical stability, hastening atherosclerosis, and increasing systemic inflammation.</p>\n</blockquote>\n\n<p>How does this relate to moderating drinking? It relates to moderate drinking through research on social circles and prolonged life spans. A team of Australian researchers found that individuals with stronger and bigger social circles have a longer life span [<a href=\"http://jech.bmj.com/content/59/7/574.abstract\">3</a>].</p>\n\n<blockquote>\n <p>Survival time may be enhanced by strong social networks. Among older Australians, these may be important in lengthening survival.</p>\n</blockquote>\n\n<p>How do we parse this information? Many who drink moderately tend to go out for that glass of wine and when they go out there is a social aspect to the setting. Husband/wife, children, dinner with other couples, etc. That is, there is a continual social bound occurring. So is it alcohol that is benefit or social circle? Does a positive social circle have an effect on stress and longevity? Luckily <a href=\"http://www.ppc.sas.upenn.edu/bio.htm\">Dr. Martin Seligman</a> from the University of Pennsylvania has already done the research. His work as well as many other researchers on the subject are cited, quoted, and expanding on in <em>Perceptions of Longevity and Successful Aging in Very Old Adults</em> by Katie E. Cherry, Loren D. Marks, Tim Benedetto, Marisa C. Sullivan, and Alyse Barker:</p>\n\n<blockquote>\n <p>Ample experimental evidence documents the association between religious participation and mortality, where religious individuals live longer than do their non-religious counterparts (e.g., McCullough, Friedman, Enders, &amp; Martin, 2009). For example, Hummer, Rogers, Nam, and Ellison (1999) have shown that Americans who attend worship services twice a week live an average of 7.6 years longer than their non-attending counterparts (a figure that nearly doubles to 13.7 years among African Americans; see Marks et al., 2005). Hummer et al.’s study was based on a national sample of 20,000+ that included a variety of faiths (Christian and non-Christian) and received the highest possible rating (‘10’) for methodological rigor (Koenig et. al., 2001, p. 562). The “key” to this longevity difference in Hummer et al. appeared to be frequency of worship service attendance, not world faith or denomination (see also Gillum, King, Obisesan, &amp; Koenig, 2008; Hill, Angel, Ellison, &amp; Angel, 2005; Musick, House, &amp; Williams, 2004) [<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864892/\">4</a>].</p>\n</blockquote>\n\n<p>Hummer et al. noted that the key to longevity was the frequency of attending a social event in this case church, but if you read the entire pub med paper in [<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864892/\">4</a>], you will see this extends to non-church social event frequency as well.</p>\n\n<p>So researchers have shown that social circles lower stress, keep people happy, and promote longevity. Many of the researchers who look at moderator drinkers don't look at the social aspect of the group just the fact that they (A) consume moderate amount of alcohol and (B) haven't died of a heart attack. Therefore, they conclude A causes B but A could be causing more social get togethers where the moderate consumption of alcohol occurs and these social settings will help reduce stress, promote community, and belonging which promotes longevity which leads to lower rates of atherosclerosis.</p>\n\n<p>From the American Red Cross circulation <em>Red Wine and your Heart</em> [<a href=\"http://circ.ahajournals.org/content/111/2/e10.full\">5</a>]:</p>\n\n<blockquote>\n <p>Despite considerable data from epidemiological studies and strong suggestions from experimental research, the evidence is still insufficient to encourage patients who do not drink to start consuming red wine as part of a strategy to protect against atherosclerosis. Too much alcohol consumption has been shown repeatedly to contribute to cardiovascular disorders such as alcoholic cardiomyopathy (which develops when the heart muscle becomes too weak to pump blood effectively), high blood pressure, and certain electrical disturbances of the heartbeat. Excessive alcohol use can lead to liver cirrhosis, cancers, pancreatitis, neurological disorders, motor vehicle accidents, and addiction. Individuals with a personal or family history of alcohol abuse or liver disease should avoid drinking alcohol. Nevertheless, many medical societies view light use of ethanol as potentially beneficial to the cardiovascular system, although no formal recommendations for light alcohol consumption have been made.</p>\n</blockquote>\n\n<p>That is, alcohol has no formal recommendation and light consumption may be <em>beneficial</em>, but again there is no mention of environment. Moreover, the Mayo Clinic makes the same statement but never analyzed the persons environment as well [<a href=\"http://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/red-wine/art-20048281?pg=2\">6</a>]. </p>\n\n<p>Until more studies start to look at social environmental factors and not just the consumption point of view, I don't think ingesting a poison to maximize life expectancy is the way to go since there is no medical recommendation on doing so; hence, it is still called the Resveratrol paradox and not a theory or fact.</p>\n", "score": 6 } ]

[ "cancer", "alcohol", "cardiovascular-disease" ]

[ { "answer_id": 710, "body": "<ul>\n<li><p>The claim that farmed salmon have more PCBs than wild salmon is\n<strong>true</strong>.</p>\n<p>For example, this paper from <a href=\"http://www.sciencemag.org/cgi/pmidlookup?view=long&amp;pmid=14716013\" rel=\"noreferrer\">Science</a> shows that the PCB (and other organic pollutant) concentrations are approximately 8 times higher in farmed than in wild salmon.</p>\n</li>\n</ul>\n<p><img src=\"https://i.stack.imgur.com/DjV7u.png\" alt=\"enter image description here\" /></p>\n<ul>\n<li>The claim that Omega-3 fatty acids are lower in farmed than wild\nsalmon is <strong>false</strong>.</li>\n</ul>\n<p>According to the USDA, <a href=\"http://ndb.nal.usda.gov/ndb/foods/show/4687?format=Full&amp;reportfmt=pdf&amp;pdfQvs=%7B%7D\" rel=\"noreferrer\">farmed salmon</a> has a higher concentration of Omega-3 fatty acids than <a href=\"http://ndb.nal.usda.gov/ndb/foods/show/4531?format=Full&amp;reportfmt=pdf&amp;pdfQvs=%7B%7D\" rel=\"noreferrer\">wild salmon</a> at 4.2g vs 3.4g for the default 1/2 fillet tested.</p>\n<ul>\n<li>The claim that dyes are added to make salmon pink is <strong>true</strong>.</li>\n</ul>\n<p><a href=\"http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019032\" rel=\"noreferrer\">This paper</a> describes an assay to measure astaxanthin content, which is one of the dyes added to the feed of farmed salmon.</p>\n<blockquote>\n<p>Astaxanthin is the single most expensive constituent in salmonid fish feed. Even though astaxanthin constitutes less than 20% of the total fish feed costs, control and optimization of the concentration of astaxanthin from feed to fish is of paramount importance for a cost effective salmonid fish production.</p>\n</blockquote>\n", "score": 6 } ]

[ "nutrition", "fish" ]

[ { "answer_id": 637, "body": "<blockquote>\n <p><strong>Carpal Tunnel Syndrome (CTS)</strong> is numbness, tingling, weakness, and other problems in your hand because of pressure on a nerve (median\n nerve) going through your wrist. <a href=\"http://www.webmd.com/pain-management/carpal-tunnel/carpal-tunnel-syndrome-topic-overview\" rel=\"nofollow\">{1}</a></p>\n</blockquote>\n\n<p>Pressure or swelling of the median nerve causes CTS and making the same hand movements over and over may induce swelling. The swelling can get even worse if the wrist is bent down (your hands lower than your wrists) or by making the same wrist movements repeatedly.</p>\n\n<p>The ergonomic mouse serves to prevent people from holding their mice on the edge of their desks or other surface, which naturally rests in a manner that bends the wrist. The person has to keep their wrist straight in order to use the mouse, thus reducing swelling over time.</p>\n\n<p>It can be annoying to adjust to an ergonomic keyboard or mouse, but they help keep the wrists straight, which can be a problem for anyone sitting all day at a computer.</p>\n\n<p>Given what an ergonomic mouse and keyboard are <em>supposed</em> to do, <strong>there is little or no data to support the concept that activity adjustment</strong> prevents carpal tunnel syndrome. The study cited below has results that are inconsistent and non-conclusive. The researchers even state in their conclusion:</p>\n\n<blockquote>\n <p>Speculative causal theories should be analyzed through a rigorous\n approach prior to wide adoption.</p>\n</blockquote>\n\n<p><a href=\"http://www.sciencedirect.com/science/article/pii/S0363502308000087\" rel=\"nofollow\">{The Quality and Strength of Evidence for Etiology: Example of Carpal Tunnel Syndrome }</a></p>\n", "score": 5 } ]

[ "computers", "tendinopathy", "ergonomics" ]

[ { "answer_id": 722, "body": "<p>The answer is \"of course,\" but one must be careful about defining terms.</p>\n\n<p>Certainly the infection can persist for years in untreated patients. That qualifies as \"chronic.\" There is no question that chronic Lyme disease exists as part of the natural history of Lyme disease.</p>\n\n<p>If you're asking whether the infectious agent can persist after what is normally a curative dose of antibiotics, the answer is also \"of course.\" A \"normally curative dose\" isn't going to be the right dose for everyone. Some people will need more, or some people will have infection in an immunologically privileged area of their body. It only takes one failure of the normally curative dose to make the answer to this scenario \"yes,\" so certainly that has happened at some point. How often is another question entirely.</p>\n\n<p>If you are asking whether ill effects of the initial infection can persist after treatment eradicates the organism, the answer is still yes. Many infections continue to exert ill effects after eradication of the infectious agent because they have incited an autoimmune response from the body. Antibiotics don't help autoimmune disorders. But again, the right question is: how often does this happen?</p>\n\n<p>If you're asking whether people who get normally curative doses of antibiotics can continue to have wacky symptoms with no trace of the infectious agent nor objectively demonstrable pathology -- well, the answer is again \"of course,\" but ... it is not (and cannot) be proven that their symptoms are due to the Lyme infection because, as noted, there is no objectively demonstrable pathology. Maybe they were going to get those symptoms anyway. Maybe their symptoms of physical illness are really symptoms of a mental illness. There is also a big problem around the term \"objectively demonstrable\" -- it depends on how thoroughly the search is made.</p>\n\n<p>Ask a simple question, get a complicated answer. :-)</p>\n\n<p>For people who want to read more:</p>\n\n<ul>\n<li><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430045/\" rel=\"nofollow\">Chronic Lyme Disease: An appraisal</a></li>\n<li><a href=\"http://www.nejm.org/doi/full/10.1056/NEJMra072023\" rel=\"nofollow\">A Critical Appraisal of “Chronic Lyme Disease”</a></li>\n</ul>\n", "score": 5 }, { "answer_id": 4532, "body": "<p><strong>Does chronic Lyme disease really exist ?</strong> Let me rewrite that question: \"Does infection with Borrelia species persist in patients treated aggressively with antibiotics? (Treated beyond the IDSA Guidelines) </p>\n\n<p>Yes, just so you know I recently posted well over 100 references supporting this position on my Facebook page Thomas Grier: and here are some to consider: <a href=\"http://www.miklossy.ch/\" rel=\"nofollow noreferrer\">Dr. Judith Miklossey</a> both photographed Borrelia in the brains of dementia patients 20 years ago, but she cultured Borrelia burgdorferi and used that strain to create a Rat Brain Model of Lyme disease. </p>\n\n<p>Alan MacDonald identified both Bb and Borrelia miyamotoi in the brain of a lumberjack from Twig MN who had been treated aggressively with 7 years of antibiotics. Green is B burgdorferi, Red is B miyamotoi <a href=\"https://i.stack.imgur.com/cFAHO.jpg\" rel=\"nofollow noreferrer\"><img src=\"https://i.stack.imgur.com/cFAHO.jpg\" alt=\"enter image description here\"></a></p>\n\n<p>Cimmino MA, Azzolini A, Tobia F, Pesce CM. Spirochetes in the spleen of a patient with chronic Lyme disease. Amer J Clin Pathol 1989;91:95-7</p>\n\n<p>Cleveland CP, Dennler PS, Durray PH. Recurrence of Lyme disease presenting as a chest wall mass: Borrelia burgdorferi was present despite five months of IV ceftriaxone 2g, and three months of oral cefixime 400 mg BID. Poster presentation LDF International Conference on Lyme Disease research, Stamford, CT, April 1992 *</p>\n\n<p>Diringer MN, Halperin JJ, Dattwyler RJ. Lyme meningoencephalitis: A report of a severe, penicillin resistant Borrelia encephalitis responding to cefotaxime.<br>\nArthritis and Rheum 1987;30:705-708</p>\n\n<p>Drulle John MD. Persisting Lyme disease: Chronic infection or immune phenomena? Lecture Handout 1992 *</p>\n\n<p>Fried Martin D, Durray P. Gastrointestinal Disease in Children with Persistent Lyme Disease: Spirochetes isolated from the G.I. tract despite antibiotic therapy. 1996 LDF Lyme Conference Boston, MA, Abstract*</p>\n\n<p>Fraser DD, Kong LI, &amp; Miller FW. Molecular detection of persistent Borrelia burgdorferi in a man with dermatomyosistis. Clin and Exp Rheum 1992;10:387-390</p>\n\n<p>Georgilis K, Peacocke M, and Klempner MS. Fibroblasts protect the Lyme Disease spirochete, Borrelia burgdorferi from ceftriaxone in vitro. J. Infect Dis 1992;166:440-444</p>\n\n<p>Hassler D, Riedel K, Zorn J, and Preac-Mursic V. Pulsed high dosed cefotaxime therapy in refractory Lyme Borreliosis (Letter to Editor) Lancet 1991;338:193</p>\n\n<p>Haupl TH, Krause A, Bittig M. Persistence of Borrelia burgdorferi in chronic Lyme Disease: altered immune regulation or evasion into immunologically privileged sites? Abstract 149 Fifth International Conference on Lyme Borreliosis, Arlington, VA, 1992 *</p>\n\n<p>Haupl T, Hahn G, Rittig M, Krause A, Schoerner C, Schonnherr U, Kalden JR and Burmester GR: Persistence of Borrelia burgdorferi in ligamentous tissue from a patient with chronic Lyme Borreliosis. Arthritis and Rheum 1993;36:1621-1626 </p>\n\n<p>Lawrence C, Lipton RB, Lowy FD, and Coyle PK. Seronegative Chronic Relapsing Neuroborreliosis. European Neurology. 1995;35(2):113-117</p>\n\n<p>Liegner KB. Lyme Disease: A persistent problem. A Guest editorial JAMA 31(8):1961-63</p>\n\n<p>Liegner KB. Lyme disease: The sensible pursuit of answers (Commentary). J. Clin Microbiol 1993;31:1961-1963</p>\n\n<p>Liegner KB. Spectrum of antibiotic-responsive meningoencephalmyelitides: A fatal case of CMEM. Poster presentation 1992 LDF Lyme Conference, Stamford, CT April 1992 *</p>\n\n<p>Liegner Kenneth B MD. Chronic persistent infection and chronic persistent denial of chronic persistent infection in Lyme Disease. A position paper presented at the 6th Annual International Conference on Lyme Disease and other tick-borne illnesses, Atlantic City, NJ, May 5-6, 1993 *</p>\n\n<p>Preac-Mursic V, Wilske B, Schierz G, et al. Repeated isolation of spirochetes from the cerebrospinal fluid of a patient with meningoradiculitis Bannwarth’ Syndrome. \nEur J Clin Microbiol 1984;3:564-565</p>\n\n<p>Preac-Mursic V, Weber K, Pfister HW, Wilske B, Gross B, Baumann A, and Prokop J. Survival of Borrelia burgdorferi in antibiotically treated patients with Lyme Borreliosis Infection 1989;17:335-339</p>\n\n<p>Schmidli J, Hunzicker T, Moesli P, et al, Cultivation of Bb from joint fluid three months after treatment of facial palsy due to Lyme Borreliosis. J Infect Dis 1988;158:905-906</p>\n\n<p>Waniek C, Prohocnik I, Haufman MA. Rapid progressive frontal type dementia and subcortical degeneration associated with Lyme disease. Poster presentation and abstract presented at the 1993 LDF State of the Art Research Symposia on Lyme Disease, Stanford, CT, April 1993 (212) 960-5872 - NY State Psychiatric Institute *</p>\n\n<p>Wokke JHJ, vanGijn J, Eldersom A, Stanek G. Chronic forms of Borrelia burgdorferi infection of the central nervous system. Neurology 1987;37:1031-1034</p>\n", "score": 2 } ]

[ "infection", "neurology", "disease" ]

[ { "answer_id": 911, "body": "<p>Despite what the supplement industry would have you believe, unless you are an overweight, older female, the commonly available steroid precursors (or the natural foods that claim to boost them) don't really have any effects on testosterone.</p>\n<p>There are three precursors (Dehydroepiandrosterone or DHEA, A'dione, and A'diol) that are hormones used in endogenous (within the body, i.e. natural) testosterone production. Many of the supplements on the market that claim to boost testosterone do increase the amount of these three hormones, but in most cases, do not lead to concurrent elevations in testosterone. (There is a <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC164360/table/T1/\" rel=\"noreferrer\">chart showing a study review with outcomes here</a>).</p>\n<p>As far as the side effects, it's best summarized by the same review paper that produced the above chart:</p>\n<blockquote>\n<p><strong>Side Effects</strong></p>\n<p>Significant reductions in serum HDL cholesterol of 12% and 20% have been observed after A'dione and DHEA supplementation, respectively. Similar changes have been observed after AAS injection and have been associated with the development of cardiovascular disease. Broeder et al administered either A'dione or A'diol (200 mg/d) and observed that both adversely affected HDL-cholesterol levels, low-density lipoprotein (LDL)-to-HDL cholesterol ratios, and coronary heart disease risk. Thus, it is possible that long-term supplementation could have serious side effects similar to those associated with AAS use, such as <strong>suppressed testosterone production, liver dysfunction, cardiovascular disease, testicular atrophy, male-pattern baldness, acne, and aggressive behavior. If the supplements are taken before puberty, premature closing of the epiphysis and stunted growth could occur. In women, precursor-induced increases in testosterone concentrations could cause lowered voice pitch, hirsutism (changes in hair growth patterns, including facial hair), increased abdominal fat accumulation, and general virilization. Furthermore, increases in estrogen concentrations experienced by men could have feminizing effects, including gynecomastia.</strong></p>\n</blockquote>\n<p>In addition to the above, there is no regulation on the supplement industry, so they may contain wildly varying levels of ingredients (Even in the same brand/line), and there have been reports of heavy metal contamination as well as contamination with actual steroid substances.</p>\n<p>Currently, you can really sum up the supplement industry in this way: If it works, it's illegal and should be only used under a doctor's care. If it is safe to use, it probably doesn't work like they claim. Also, while many people do not realize it, if you participate in 5k fun runs, amateur cycling, or any amateur competition where the governing body adheres to USADA (or the local national equivalent) strictures, you can be subject to testing, no matter your competitive level. Many supplements would cause you to test positive if you were selected. You can always get a current list of banned supplements at the <a href=\"http://www.supplement411.org/hrl/\" rel=\"noreferrer\">Supplement 411 site</a>.</p>\n<p>If interested, all of the studies referenced in the above paper are listed with links below the paper writeup itself.</p>\n<p>One caveat: Creatine Monophosphate is a legal supplement that has been proven to do what it says. It doesn't create more muscle, but it does create a bigger pool of energy rich fluid in the muscle to draw from, so that you can work out longer, which in turn will create more muscle.</p>\n", "score": 8 }, { "answer_id": 15679, "body": "<p>Other than the post and the website you mentioned, here are a few more natural testosterone boosters, some of them being substances, and others being lifestyle changes or things-to-do:</p>\n\n<p>1) In this <a href=\"https://www.researchgate.net/publication/275716515_Pomegranate_juice_intake_enhances_salivary_testosterone_levels_and_improves_mood_and_well_being_in_healthy_men_and_women\" rel=\"nofollow noreferrer\">study</a>, pomegranates were found to increase salivary testosterone levels by an average of 24% (though this was averaged over both men and women, in just men, the increase was ~22%).</p>\n\n<p>2) In this <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/26609282\" rel=\"nofollow noreferrer\">study</a>, the Ashwagandha group, in conjunction with resistance training, was able to increase their testosterone by 96.2 ng/dl, compared to the placebo group, that was only able to increase their testosterone levels by 18 ng/dl.</p>\n\n<p>3) In this <a href=\"https://www.physiology.org/doi/abs/10.1152/jappl.1997.82.1.49\" rel=\"nofollow noreferrer\">study</a>, significant correlations were observed between dietary intake and testosterone levels. My interpretation from the correlations in this study was that, in general, higher protein intake and higher polyunsaturated fatty acids (PUFA's) result in lower testosterone levels, while more carbohydrates, higher monounsaturated fatty acids (MUFA's) and saturated fatty acids (SFA's) result in higher testosterone levels.</p>\n\n<p>4) Coming to the more controversial one, in this <a href=\"http://www.abc.net.au/catalyst/chemistryofattraction/download/Oberzaucher_Poster.pdf\" rel=\"nofollow noreferrer\">study</a>, whiffing the pheromone copulin, which is secreted by ovulating females, increased salivary testosterone levels by an average of about 30%, as seen in the graph). Copulins are available on amazon; however, I have been unable to find the exact concentration of copulins used in this study and the time of exposure of the subjects to them, so proceed with your own risk.</p>\n\n<p>5) The safer alternative to the above option, which depending on your circumstances, may or may not be available to you, is sexual intercourse. In this <a href=\"https://link.springer.com/article/10.1007/s10508-010-9711-3/fulltext.html\" rel=\"nofollow noreferrer\">study</a>, participants in a visit to the sex club experienced a 72% increase in testosterone levels. Even the observers experienced an 11% increase as well.</p>\n\n<p>6) In this <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Pituitary-testicular+axis+in+obese+men+during+short-term+fasting.\" rel=\"nofollow noreferrer\">study</a>, a 56 hours fast was observed to increase testosterone levels by 180% in normal non-obese men but not by any percentage in obese men, sadly.</p>\n\n<p>7) In this <a href=\"http://www.ehbonline.org/article/S1090-5138(13)00065-2/fulltext\" rel=\"nofollow noreferrer\">study</a>, men who chopped trees for one hour experienced a 48.6% rise in testosterone levels. I quote from the study: \"A comparison of these results to the relative change in testosterone during a competitive soccer tournament in the same population reveals larger relative changes in testosterone following resource production (tree chopping), compared to competition (soccer).\"</p>\n\n<p>8) In this <a href=\"https://www.ncbi.nlm.nih.gov/pubmed/22995464\" rel=\"nofollow noreferrer\">study</a>, ingestion of 3000 mg of Royal Jelly caused an increase in testosterone levels (log testosterone levels in the RJ group was +0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL in the placebo group).</p>\n", "score": 4 } ]

[ "natural-remedy", "testosterone" ]

[ { "answer_id": 3808, "body": "<p>First of all, I would suggest doing extensive research into natural-remedies and be extremely cautious.</p>\n\n<p>I understand that your original question was referring to the method, however I believe this information is relevant, as there are factors to take into account that suggest the method of direct ingestion may not be safe. Ultimately, you should contact a professional.</p>\n\n<p>There is not enough scientific information to determine an appropriate range of doses for neem. Keep in mind that natural products are not always necessarily safe and dosages can be important. <strong>Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.</strong></p>\n\n<p>WebMD, not always accurate, does specify that Neem is taken orally, though it doesn't indicate what form (powder, leaf, pill, etc.). It has the following warnings and precautions about Neem in general:</p>\n\n<p><br/><br/><br/></p>\n\n<blockquote>\n <p><h3>Overview</h3> Neem is POSSIBLY SAFE for most adults when taken by\n mouth for up to 10 weeks, when applied inside the mouth for up to 6\n weeks, or when applied to the skin for up to 2 weeks. <strong>When neem is\n taken in large doses or for long periods of time, it is POSSIBLY\n UNSAFE. It might harm the kidneys and liver.</strong></p>\n \n <h3>Children</h3>\n \n <p><strong>Taking neem seeds or oil by mouth is LIKELY UNSAFE for children.</strong> <strong>Serious side effects</strong> in infants and small children can happen <strong>within hours</strong> after taking neem oil. These serious side effects include vomiting, diarrhea, drowsiness, blood disorders, seizures,\n loss of consciousness, coma, brain disorders, and death.</p>\n \n <p><h3>Pregnancy/Breast-Feeding</h3> Neem oil and neem bark are <strong>LIKELY\n UNSAFE</strong> when taken by mouth during pregnancy. They <strong>can cause a\n miscarriage.</strong></p>\n \n <p>Not enough is known about the safety of need during breast-feeding.\n Stay on the safe side and avoid use.</p>\n \n <p><h3>Auto-immune diseases</h3> Multiple sclerosis (MS), lupus (systemic\n lupus erythematosus, SLE), rheumatoid arthritis (RA), or other similar\n conditions: Neem may cause the immune system to become more active,\n possibly increasing the symptoms of auto-immune diseases. <strong>If you\n have one of these conditions, it’s best to avoid using neem.</strong></p>\n \n <p><h3>Diabetes</h3> There is some evidence that neem can lower blood\n sugar levels and might cause blood sugar to go too low. <strong>If you have\n diabetes and use neem, monitor your blood sugar carefully.</strong> It might\n be necessary to change the dose of your diabetes medication.</p>\n \n <p><h3>Infertility</h3> There is some evidence that neem can harm sperm.\n It might also reduce fertility in other ways. <strong>If you are trying to\n have children, avoid using neem.</strong></p>\n \n <p><h3>Organ Transplant and Surgery</h3> There is a concern that neem\n might decrease the effectiveness of medications that are used to\n prevent organ rejection. <strong>Do not use neem if you have had an organ\n transplant.</strong> </p>\n \n <p>Neem might also lower blood sugar levels as mentioned earlier. There\n is a concern that it might interfere with blood sugar control during\n and after surgery. <strong>Stop using neem at least 2 weeks before a\n scheduled surgery.</strong></p>\n</blockquote>\n\n<p>It would be safer to avoid direct leaf intake for children, the pregnant, and those trying to have a baby as well as those who have recently had a transplant.</p>\n\n<p><a href=\"http://www.webmd.com/vitamins-supplements/ingredientmono-577-neem.aspx?activeingredientid=577&amp;activeingredientname=neem\" rel=\"nofollow\">http://www.webmd.com/vitamins-supplements/ingredientmono-577-neem.aspx?activeingredientid=577&amp;activeingredientname=neem</a></p>\n", "score": 2 } ]

[ "dermatology", "medications", "natural-remedy" ]

[ { "answer_id": 1172, "body": "<p>As you read, both TENS and EMS employ electrotherapy to treat acute and chronic pain, but the methodology differs. (Note that some of the references are to NMES, which stands for Neuromuscular Electrical Stimulation, and is considered synonymous with EMS.)</p>\n<p>Transcutaneous Electrical Nerve Stimulators (TENS) use electrotherapy to <a href=\"http://www.tensunitreviews.net/tens-vs-ems/\" rel=\"noreferrer\">stimulate the nerves</a> and active therapeutic healing. Electronic Muscle Stimulators (EMS), on the other hand, sends electric impulses that cause <a href=\"http://www.tensunitreviews.net/tens-vs-ems/\" rel=\"noreferrer\">muscle contraction</a>. EMS units are used to prevent atrophied muscles, for retraining muscles (e.g. in partial paralysis), to increase range of motion, and other uses.</p>\n<p>Some of the technology is described <a href=\"http://www.tensunitreviews.net/tens-vs-ems/\" rel=\"noreferrer\">here</a>.</p>\n<blockquote>\n<p>A TENS unit uses microcurrent to increase the production of ATP, which is adenosine triphosphate and the substance that supplies energy to the body on a cellular level. Although lasting pain reduction may require regular microcurrent sessions, in some individuals the pain reduction begins to last longer and the time between sessions lengthens. This may be due to the increased circulatory action that enables the lymph system to begin clearing the body of accumulated toxins. The sensations of both the microcurrent and conventional TENS treatments are more like tingling sensations than the unpleasant feeling of a small electrical shock.</p>\n<p>EMS uses a cycle of stimulation, contraction and then relaxation, to increase blood flow to the area, which decreases inflammation and promotes healing and muscle growth. By stimulating the muscles at their basic structure, an EMS unit causes muscle contractions similar to those obtained by exercise. The EMS units are specifically used to prevent atrophied muscles or for retraining muscles, such as in an individual who has been paralyzed or partially paralyzed. In addition, EMS is used for many other applications such as range of motion improvement, increased circulatory action and the prevention of blood clots.</p>\n</blockquote>\n<p>Both types of therapies are convenient, in that they're used at home, and the patient controls the dose, generally by way of either a knob or a switch. Electrodes are user-replaceable, though placement instructions are given and monitored by a physician or physical therapist. TENS units also have a &quot;burst&quot; feature, enabling the patient intermittent increases, which is helpful after strenuous activity or if you're just having a bad day. I personally found that feature very helpful!</p>\n<p>A Yale University study entitled <a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3375668/\" rel=\"noreferrer\">Neuromuscular Electrical Stimulation for Skeletal Muscle Function</a>(Yale J Biol Med. 2012) discussing electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical stimulation (FES) states that the potential that electrical stimulation holds for rehabilitation recovery is immeasurable. It is used to improve muscle strength, increase range of motion, reduce edema, decrease atrophy, heal tissue, and decrease pain.</p>\n<blockquote>\n<p>Neuromuscular electrical stimulation (NMES), used interchangeably with electrical stimulation (ES), is typically provided at higher frequencies (20-50 Hz) expressly to produce muscle tetany and contraction that can be used for “functional” purposes and can be found in literature as early as 1964. TENS is an alternate form of electrical stimulation that historically used high frequencies for pain relief but is now also administered at very low frequencies (sensory level TENS, 2-10 Hz). <em>TENS propagates along smaller afferent sensory fibers specifically to override pain impulses.</em> When very low frequencies are used, TENS specifically targets sensory nerve fibers and does not activate motor fibers; therefore, no discernible muscle contraction is produced.</p>\n</blockquote>\n<p>This source also has chapters on other subjects pertinent to your question, including, among others:</p>\n<ul>\n<li>Parameters of electrical stimulation</li>\n<li>Pulse width/duration</li>\n<li>Stimulation pulse patterns</li>\n<li>Stimulation intensity</li>\n<li>Dosing of stimulation</li>\n<li>Limitations of electrical stimulation.</li>\n</ul>\n<p>In addition, you may also be interested in the following charts:</p>\n<ul>\n<li><p>For EMS, <a href=\"http://www.electrotherapy.org/assets/Downloads/NMES%20Muscle%20Stimulation%20march%202013.pdf\" rel=\"noreferrer\">this</a> describes in detail which muscles are targeted by names, and at which frequencies.</p>\n</li>\n<li><p><a href=\"http://www.tensunits.com/chart.html\" rel=\"noreferrer\">This</a>\nshows placement of electrodes of TENS unit, based on the location of the pain.</p>\n</li>\n</ul>\n<p>_{For further information, including uses, cautions and case studies, see:}<br />\n_{<a href=\"http://emedicine.medscape.com/article/325107-overview#aw2aab6b40\" rel=\"noreferrer\">Transcutaneous Electrical Nerve Stimulation</a>}<br />\n_{<a href=\"http://journals.lww.com/nsca-jscr/Abstract/publishahead0/Effects_of_Three_Recovery_Protocols_on_Range_of.97263.aspx\" rel=\"noreferrer\">Effects of Three Recovery Protocols on Range of Motion, Heart Rate, Rating of Perceived Exertion, and Blood Lactate in Baseball Pitchers During a Simulate Game.</a>}<br />\n_{<a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758879/\" rel=\"noreferrer\">Serratus muscle stimulation effectively treats notalgia paresthetica caused by long thoracic nerve dysfunction: a case series</a>}<br />\n_{<a href=\"http://tensunitshop.com/understanding-the-differences-between-tens-and-ems-units/\" rel=\"noreferrer\">Understanding the Differences Between TENS and EMS Units</a>}<br />\n_{<a href=\"http://www.tensunits.com/work.html\" rel=\"noreferrer\">How Does A Tens Unit Work?</a>}</p>\n", "score": 8 } ]

[ "pain", "medical-device" ]

[ { "answer_id": 1177, "body": "<p>This is a very interesting question. It's also highly speculative, and vague (what does &quot;a doctor... gives them any medicine necessary to protect them from other diseases that might be lurking in their body&quot; mean? Does it mean they treat the symptoms of AIDS (weight loss, diarrhea, etc?) If it does, then the difference between not treating HIV but treating every complication stretches this almost to the point of meaninglessness. If you are postulating treating all diseases, then I do believe this is speculative at best and unanswerable.</p>\n<p>The most likely scenario is that the patient would eventually die (but don't we all?) How he would die is pure speculation.</p>\n<p>Unfortunately, while you can place a patient in a sterile environment,</p>\n<ol>\n<li><p>you can't sterilize a patient</p>\n</li>\n<li><p>it's exceedingly difficult to sterilize food</p>\n</li>\n<li><p>to prevent all possible hospital acquired bacterial infections, they would need a bubble-boy-like unit (very rare and extremely expensive)</p>\n</li>\n<li><p>you can't predict if some previously unknown virus dormant in our bodies will be able to express itself. (See @Fomite's comment.)</p>\n</li>\n</ol>\n<p>The fact that you stipulate treatment for everything but the virus that replicates in certain blood cells associated with immunity is almost an aside if you're going to treat all pathogens.</p>\n<p>Every bacteria and virus he has in his body will go into that sterile environment with him, so it depends what he has going in. When he no longer has enough immune competency to keep these under control, they will take their toll. If you treat him in a sterile environment and give him world-class treatment of all infections (anti-virals would be needed to treat herpesvirus recurrences, like chicken pox and HSV1, HCV, HepBV, or any other number of viruses one can carry, treat the encephalitis that comes with HSV/etc. He has a small chance of possibly outliving the disease, only to die in the 3-5 days after you turn him out, unless you include bone marrow transplant in the treatment as well.</p>\n<p>The progress of HIV to AIDS is variable. Less than 0.5% of patients never develop any sign whatsoever of the infection except for undeniably positive titers. What if your patient is in this small but not-nonexistent subtype? Then there are almost everything in between, with fewer patients on the healthy end than the sick end.</p>\n<p>My best guess: your patient will die of some ultimately unconquerable disease you are treating in the bubble, for example, multi-drug resistant C. diff, Kaposi's sarcoma, Mycobacterium avium-intracellulare, Toxoplasmosis (Up to 50% of the world's human population is estimated to carry Toxoplasma) liver failure from rampant Epstein-Barr, or some other opportunistic infection from something he carried in there but is either devastating or drug resistant.</p>\n<p>You're asking if the virus will just &quot;die&quot; out, effectively curing the patient. That's kind of like letting the heart and lungs die, but keeping the patient alive on a heart-lung bypass machine. That's not a cure, and upon turning it off, the patient will die.</p>\n<p>And that's purely a guess, which, on SE, makes it worthless.</p>\n<p>_{<a href=\"http://jama.jamanetwork.com/article.aspx?articleid=186199\" rel=\"nofollow noreferrer\">Long-term Nonprogressive Disease Among Untreated HIV-Infected Individuals: Clinical Implications of Understanding Immune Control of HIV</a>}</p>\n", "score": 9 }, { "answer_id": 4271, "body": "<p>In addition to what anongoodnurse wrote about the patient likely dieing, I don't think this scenario would work at all. </p>\n\n<p>HIV doesn't infect all immune cells. It infects <a href=\"https://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/hiv-in-your-body/hiv-lifecycle/\" rel=\"noreferrer\">T-cells/CD4 cells</a>, which are used for adaptive immunity. There are two features of HIV infections that make your scenario impossible or almost impossible:</p>\n\n<ol>\n<li>The time between infection of a cell and lysis (death) can be long, <a href=\"http://www.nature.com/ncomms/2015/151020/ncomms9447/full/ncomms9447.html\" rel=\"noreferrer\">and it can even stay dormant</a>. So there can always be cells that are infected and it can take years before the virus emerges from them </li>\n<li>In the meantime, new T-cells are produced by the body, even in patients with HIV, though very slowly. The bone marrow that produces them is still there. </li>\n</ol>\n\n<p>In some people with AIDS, the number of CD4 cells counted in <a href=\"http://www.aids.org/topics/aids-factsheets/aids-background-information/what-is-aids/hiv-testing/cd4-t-cell-tests/\" rel=\"noreferrer\">blood samples actually goes down to 0</a>, which would be as close to your scenario as people can get and it still doesn't make them cured. The \"viral load\" measured in these patients is usually very high. Remember that HIV needs human cells to <em>reproduce</em>, not to <em>survive</em>. It will happily exist in an individual with no CD4 cells. That person can infect others and because the immune system can't replenish the CD4 cells fast enough (and they get infected soon after being produced) the immune system just stays very, very weak. </p>\n\n<p>The stem cell therapy approach to HIV was mentioned in comments, so I'd like to address that. It's not as \"easy\" as just doing a bone marrow transplant. The new cells would just get infected. <a href=\"https://www.cirm.ca.gov/our-progress/disease-information/hivaids-fact-sheet\" rel=\"noreferrer\">The donor has to be immune to HIV</a> (some people are due to a mutation), so the newly produced cells can't be infected by the virus. Unfortunately, the mutation is rare. </p>\n", "score": 5 } ]

[ "immune-system", "virus", "hiv" ]

[ { "answer_id": 1547, "body": "<p>As I argue in my answer to <a href=\"https://health.stackexchange.com/questions/1481/are-all-kinds-of-liquor-and-alcohol-equally-bad-for-liver/1518#1518\">this question</a>, there seems to be a threshold in terms of the amount of alcohol likely to cause hepatocellular necrosis based on the production of acetaldehyde. However, alcohol causes damage to other cells in the body such as in the <a href=\"http://pubs.niaaa.nih.gov/publications/aa63/aa63.htm\" rel=\"nofollow noreferrer\">brain</a> and <a href=\"http://www.alcoholanswers.org/alcohol-education/health-topics/alcohol-and-mouth-esophagus.cfm\" rel=\"nofollow noreferrer\">throat</a>. Since your example is of hard liquor, there would be damage to the mouth and esophagus not present from consumption of more dilute solution. Although beyond the scope of your question, many people would consider changes like habituation to the effects and long-term tolerance, and even \"developing an acquired taste\" which could increase the propensity for alcoholism, to be harmful.</p>\n\n<p><a href=\"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1343022/\" rel=\"nofollow noreferrer\">A study</a> of two hospitalized toddlers found that their alcohol consumption was somewhat under 20 mL for the first one (who drank an acetaminophen elixir) and 2 to 7 mL for the second one (who drank mouthwash and collapsed). So it seems that toddlers are more sensitive to the depressant effect of alcohol than adults per kg of body weight, and that it is feasible for them to drink enough alcohol to suffer respiratory arrest.</p>\n\n<p>There is a whole <a href=\"http://www.reddit.com/r/askscience/comments/13xyho/are_really_small_amounts_of_alcohol_harmful_for/\" rel=\"nofollow noreferrer\">thread</a> on reddit discussing your very question. None of the answers were satisfyingly quantitative, but people pointed out that some pediatric medications contain ethanol (which should make it possible to calculate a \"sanctioned\" dose), that people in France and other places have a history of giving a little alcohol to young children, that ethanol is a metabolite (rum flavoring) or additive (flavoring extracts) in some foods, that it forms spontaneously in sugar-containing foods like juice and that it can form naturally in the intestine. So any of these approaches should make it possible to estimate a \"normal\" exposure of toddlers to ethanol, if not a \"safe\" one.</p>\n", "score": 4 } ]

[ "lasting-effects-duration", "alcohol", "pediatrics", "enzyme", "toddler" ]

[ { "answer_id": 1269, "body": "<p>Unfortunately, height is genetically based.</p>\n\n<p>At 24 years old, it is unlikely that you will grow more, but the only way to know for sure is if you have an x ray done of the growth plates in your bones to see if they have disappeared. If they have, then there really is no natural way to increase height.</p>\n\n<p>There are surgical procedures (<a href=\"http://www.digitaljournal.com/article/320199\">See this article</a>) where you can potentially add a few inches, but they are very costly (The procedure described in the article cost ~ $90,000 US dollars), and they are reported to be very painful, long (3+ months) and require extensive rehabilitation and physical therapy to be successful. According to the article, most places that do the procedure use it primarily for physical afflictions such as dwarfism, and do not recommend it for purely cosmetic reasons.</p>\n", "score": 11 }, { "answer_id": 15517, "body": "<p>The only known non-surgical method of gaining height at this age is to go into space. Without the pull of earth's ground level gravity astronauts have been shown to gain height.</p>\n\n<blockquote>\n <p>Astronauts in space can grow up to 3 percent taller during the time spent living in microgravity, NASA scientists say. That means that a 6-foot-tall (1.8 meters) person could gain as many as 2 inches (5 centimeters) while in orbit.</p>\n</blockquote>\n\n<p>However, this height is lost once earth's full gravity is restored.</p>\n\n<p><a href=\"https://www.space.com/19116-astronauts-taller-space-spines.html\" rel=\"nofollow noreferrer\">https://www.space.com/19116-astronauts-taller-space-spines.html</a></p>\n", "score": 4 } ]

[ "height", "growth-hormones" ]

[ { "answer_id": 1329, "body": "<p>I think your skepticism may come from not understanding the process behind the claim. </p>\n\n<p>A single unit of blood is separated into 4 main \"blood products\": red blood cells, plasma, platelets, and white blood cells. Another product called cryoprecipitate can be produced from frozen then thawed plasma and is used in special circumstances. Whole blood is rarely used for transfusions anymore because of problems with transfusion reactions and, quite frankly, except in the case of massive hemorrhage, a single person rarely needs all these components all at once (and even then they probably won't need white blood cells). Red blood cells (or packed red blood cells) are what most people think of when they get a \"blood transfusion.\" Plasma is given to people who do not have enough clotting factors in their blood to stop bleeding that is currently occurring or if it should occur. Platelets are given to people who are not producing enough platelets to keep them from bleeding to death. White blood cells are rarely given anymore, but there may be occasion to use them in specific cases.</p>\n\n<p>Now did that one unit save up to 3 lives? Well, to answer that the question of whether their lives were in danger to begin with has to be answered. The answer is, \"Yes!\" When will they die without the product? For some it's in the next several minutes, for others it may be hours, days or weeks, but in every case these peoples lives are in danger without the products derived from human blood.</p>\n\n<p>But did that unit all by itself achieve this? No, but in concert with the donations of others it <strong>contributed</strong> to saving \"up to 3 lives.\" Because doctors try avoid using precious blood products until it is absolutely necessary by treating patients with other methods if possible, so by the time a person definitely requires blood products, they will get more than one unit, but had they been given products earlier without giving the 'other methods' a chance to work they would have needed just as much, maybe more, over time.</p>\n\n<p>The American Cancer Society has an excellent <a href=\"http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/bloodproductdonationandtransfusion/blood-transfusion-and-donation-types-of-transfusions\" rel=\"noreferrer\">summary of types of blood transfusions and what they are used for here</a>. </p>\n\n<p>I don't think the claim is derived from any particular set of statistics or the hard and fast numbers that you are seeking, but from the process involved.</p>\n\n<p><strong>EDIT:</strong></p>\n\n<p>The best collection of statistical information online may be <a href=\"http://www.nlm.nih.gov/medlineplus/bloodtransfusionanddonation.html\" rel=\"noreferrer\">Blood Transfusion and Donation</a> published by the National Institutes of Health and <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf\" rel=\"noreferrer\">The 2011 National Blood Collection and Utilization Survey Report (PDF)</a>, published by the US Department of Health and Human Services (and several other departments and agencies). These 2 documents contain the most current comprehensive data available on blood collection and transfusion.</p>\n", "score": 15 }, { "answer_id": 3909, "body": "<p>I'm answering my own question, yay! This is my attempt to answer my question despite my lack of familiarity with much of the medicine. I therefore stress that I am not guaranteeing this answer, it's meant to be a very rough estimate and shouldn't be considered exact. Perhaps others will comment on things I missed and allow me to make it better...</p>\n\n<p>First, Here is a quick link that discusses the concept: <a href=\"http://blog.inceptsaves.com/blog/2010/10/27/donor-recruitment-how-can-one-pint-of-blood-save-three-lives/\" rel=\"noreferrer\">http://blog.inceptsaves.com/blog/2010/10/27/donor-recruitment-how-can-one-pint-of-blood-save-three-lives/</a></p>\n\n<p>So there are three types of products that can be produced from whole blood, and each is divided into a nice 'unit', a base number used to define how much of a product is ordered by a hospital. However, one whole blood donation does not make up a full unit in any of these three. So what we get is:</p>\n\n<ol>\n<li>Red Blood Cells(RDC): little less then 2 donations per unit</li>\n<li>Platelets: 5-6 (I've seen both numbers, 6 seems more common) donations per unit</li>\n<li>plasma: less certain, I think about 2 donations per unit?</li>\n</ol>\n\n<p>Thus for 10 donations of red blood cells you will have produced 2 unit if platelets and 5 units of RDC and Plasma. If one unit was required to save a life then you will save 12 lives with those 10 donations, or 1.2 lives per donation.</p>\n\n<p>However, it looks like many units are required per operation/transfusion/emergency. </p>\n\n<p><strong>Red Blood Cells</strong></p>\n\n<p>in 2010 on average <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf#page26\" rel=\"noreferrer\">2.75 units were used per patient</a>. This is not anywhere near an accurate estimate of units needed per 'life saved', but I'm trying for a very very rough estimate. So for now lets say that each transfusion saved a life, and thus it took roughly 5.25 whole blood donations per 'life saved' via RBC. In actuality the odds are not every patient was in a life critical situation, so we should look at the number of units used per patient who was in a life critical situation, but I don't have that number. Since it seems likely that those in non-life critical situations would likely require less RBC then those in a life critical situation I would assume the units used per life-critical operation are higher, meaning the overall lives saved per whole blood donation is lower, but I don't have statistics on this.</p>\n\n<p><strong>Platelets</strong></p>\n\n<p>I know it can take up to <a href=\"http://www.universityhealthsystem.com/plateletpheresis/\" rel=\"noreferrer\">30 units</a> for a single organ donation; but that's probably a high estimate, to stress the importance of donations.</p>\n\n<p>Bone marrrow transplants used <a href=\"http://jco.ascopubs.org/content/19/5/1519.full\" rel=\"noreferrer\">54 PC in the 100 days post transfer</a>, where a PC is defined to be the amount of platelets from a single donation of whole blood, but was also defined as requiring 9-6 PC to make a full unit; so a slight discrepancy from other numbers. I would put that at an average of 5 units per bone marrow transfer?</p>\n\n<p>The average <a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf#page40\" rel=\"noreferrer\">pre-transfusion platelet count was 32,055</a> with a healthy platelet count being <a href=\"https://www.nlm.nih.gov/medlineplus/ency/article/003647.htm\" rel=\"noreferrer\">150,000 to 400,000</a>. One unit should raise platelet count by <a href=\"http://pathology.ucla.edu/workfiles/2-3-Platelet-Products.pdf\" rel=\"noreferrer\">30,000-50,000</a>. If we assume they would transfere enough platelets to get someone up to close to the lower end of 'healthy', 150,000, then they would need another 3-4 units per transfusion. This seems in keeping with other math I saw, with all surgeries looking to require 5+ units. Going with a favorable comparison lets say an average of 3 units per life-saving transfusion. I'm not at all confident with this number, but it's the best I've managed so far.</p>\n\n<p>With that number were looking at 15-18 whole blood donations per one life saved with platelets.</p>\n\n<p><strong>Plasma</strong></p>\n\n<p>I give up and throw up my hands here. Plasma is broken down into many different products, and trying to get averages for all those products to expand on the average units used is just too much.</p>\n\n<p>for now, until I get around to doing better research, lets be extra generous and assume every unit saves one life. I highly doubt this, I would say it's likely that it's at least a minimum of 2 units per life saved, but I'm trying to stay on the generous side; and lacking any statistics I can at least say that they define units as a minimal quantity likely suggests they don't expect adults to ever need less then 1 unit per transfer which implies at least one is needed per life saving intervention. </p>\n\n<p>Giving that likely generous presumption were looking at 1 life saved per two whole blood donations via plasma.</p>\n\n<p><strong>Other products</strong></p>\n\n<p>There are other products that can be made out of whole blood. None of them are nearly as useful as the above, and rarely are collected, but at least some of them are utilized and would add to overall lives saved by a very small amount. I don't feel like adding them up since it sounds like they are such a minimal affect, and won't. That's because I think any lives preserved via these methods is counteracted by...</p>\n\n<p><strong>Waste and outdating</strong></p>\n\n<p><a href=\"http://www.hhs.gov/ash/bloodsafety/2011-nbcus.pdf#page27\" rel=\"noreferrer\">Just under 5% of all blood products go unused</a> due to waste or being too old. I figure this waste more then counteracts the above other products, so I'm going to ignore both and just pretend they two affects perfectly countered each other.</p>\n\n<p><strong>Final assessment</strong></p>\n\n<p>This is all very <em>very</em> rough math by a layman, so I am not swearing to any of it. I was trying to error on the side of presuming maximum number of lives saved per donation; though it's entirely possible I missed an important factor which caused me to underestimate these numbers; feedback is welcome.</p>\n\n<p>However, as the math works out we have:</p>\n\n<ul>\n<li>5.25 Whole Blood Donations per life saved (HBD/L) for RBC</li>\n<li>15 HBD/L for platelets</li>\n<li>2 HBD/L as a very generous presumption for plasma.</li>\n</ul>\n\n<p>This works out to .757 lives saved per donation.</p>\n\n<p>so a little less then 1 life saved per donation at my most generous; though I fear my being lazy and not doing a plasma calculation likely raised that number higher then it really should be. Assuming I haven't made some obvious miscalculation; which is quite possible!</p>\n\n<p>So every 2 whole blood donations you make will save a life! I've been donating for about 10 years now at about 1 donation per 2 months, so that still means more then 30 lives saved. Still not bad considering how little it really costs me.</p>\n\n<p>I welcome feedback from anyone who has more knowledge about this then...well a geek googling random statistics who may be able to point out factors I missed. This is definitely not definitive; but it's nice to have at least a rough rule of thumb.</p>\n", "score": 6 }, { "answer_id": 24389, "body": "<p>Here are some statistics:\nEach year, an estimated 6.8 million people in the U.S. donate blood.\n<a href=\"https://www.redcrossblood.org/donate-blood/how-to-donate/how-blood-donations-help/blood-needs-blood-supply.html\" rel=\"noreferrer\">13.6 million</a> whole blood and red blood cells are collected in the U.S. in a year.\nGiving blood saves <a href=\"https://blog.stridehealth.com/post/save-3-lives-with-1-blood-donation\" rel=\"noreferrer\">4.5 million</a> lives each year in the U.S.</p>\n<p>The Jehovah's Witness patients' decision to forego transfusions for major surgical procedures appears to add <a href=\"https://www.bmj.com/rapid-response/2011/10/28/risk-blood-transfusion-illegal-breach-confidentiality-addendum-reply-furul\" rel=\"noreferrer\">0.5% to 1.5% mortality</a> to the overall operative risk</p>\n<p>13.6 million blood donations is used for 4.5 million people. This is .33 people per donation. Using the Jehovah's Witness information then about .5 to 1.5 % of these would actually die without blood. This is .0016 to .0050 people per blood transfusion. So this implies something like 200 to 600 blood transfusions to save a life. At first glance this seems small which is why the number is not readily available. However, you can look at it another way. People who need blood are often of middle age where they have a life expectancy of 30 years or about 8,000 days. So you are saving somewhere between 13 and 40 days of life for every blood donation on the average. One hour or so and 13-40 days of life are added. This seems wonderful.</p>\n", "score": 5 } ]

[ "blood", "blood-donation" ]