Claim: Choose Omega-3s from fish over flax for cancer prevention, study finds
Verdict: REFUTES

Retrieved passages:
title: Fish oil
text: aggressive prostate cancer with higher blood levels of combined EPA and DHA. Some evidence indicated an association between high blood levels of omega-3 fatty acids and an increased prostate cancer risk. Fish oil supplement studies have failed to support claims of preventing heart attacks or strokes. Earlier, in 2007, the American Heart Association had recommended the consumption of 1 gram of fish oil daily, preferably by eating fish, for patients with coronary artery disease, but cautioned pregnant and nursing women to avoid eating fish with high potential for mercury contaminants including mackerel, shark, and swordfish. (Optimal dosage was related to

title: Omega-3 fatty acid
text: for products that contain at least 250 mg EPA + DHA. The report did not address the issue of people with pre-existing heart disease. The World Health Organization recommends regular fish consumption (1-2 servings per week, equivalent to 200 to 500 mg/day EPA + DHA) as protective against coronary heart disease and ischaemic stroke. Heavy metal poisoning by the body's accumulation of traces of heavy metals, in particular mercury, lead, nickel, arsenic, and cadmium, is a possible risk from consuming fish oil supplements. Also, other contaminants (PCBs, furans, dioxins, and PBDEs) might be found, especially in less-refined fish oil supplements.

title: Prostate cancer
text: consumption of the Western diet. There is little if any evidence to support an association between trans fat, saturated fat, and carbohydrate intake and risk of prostate cancer. Evidence regarding the role of omega-3 fatty acids in preventing prostate cancer does not suggest that they reduce the risk of prostate cancer, although additional research is needed. Vitamin supplements appear to have no effect and some may increase the risk. High calcium intake has been linked to advanced prostate cancer. Consuming fish may lower prostate cancer deaths but does not appear to affect its occurrence. Some evidence supports lower rates of

title: Fish oil
text: EPA and DHA. The Guidelines were revised again for 2015-2020; included is a recommendation that adults consume at least eight ounces of a variety of types of fish per week, equating to at least 250 mg/day of EPA + DHA. The Food and Drug Administration recommends not exceeding 3 grams per day of EPA + DHA from all sources, with no more than 2 grams per day from dietary supplements. The effect of fish oil consumption on prostate cancer is controversial, as one study showed decreased risk with higher blood levels of DPA, whereas another reported increased risk of more

title: Omega-3 fatty acid
text: and DHA include fish, fish oils, eggs from chickens fed EPA and DHA, squid oils, and krill oil. Dietary supplementation with omega−3 fatty acids does not appear to affect the risk of death, cancer or heart disease. Furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes or any vascular disease outcomes. Omega−3 fatty acids are important for normal metabolism. Mammals are unable to synthesize omega−3 fatty acids, but can obtain the shorter-chain omega−3 fatty acid ALA (18 carbons and 3 double bonds) through diet and use it to form the more important long-chain

title: Omega-3 fatty acid
text: due to their cardiovascular benefits: individuals with no history of coronary heart disease or myocardial infarction should consume oily fish two times per week; and "Treatment is reasonable" for those having been diagnosed with coronary heart disease. For the latter the AHA does not recommend a specific amount of EPA + DHA, although it notes that most trials were at or close to 1000 mg/day. The benefit appears to be on the order of a 9% decrease in relative risk. The European Food Safety Authority (EFSA) approved a claim "EPA and DHA contributes to the normal function of the heart"

title: Canadian health claims for food
text: help prevent or treat cancer and that more studies need to be done. A study published in the Journal of the National Cancer Institute was done on 1300 prostate cancer patients. Overall the risk of prostate cancer was unaffected by receiving dietary supplemental antioxidants. However, the results in smokers show that an increase in Vitamin E and B-carotene are statistically significant and are associated with reduced risk of the disease. Lycopene is a strong antioxidant found in large quantities in tomatoes as well as other red fruits and vegetables. It has recently been a subject of great research concerning many

title: Omega-3 fatty acid
text: A 2018 meta-analysis found no support that daily intake of one gram of omega-3 fatty acid in individuals with a history of coronary heart disease prevents fatal coronary heart disease, nonfatal myocardial infarction or any other vascular event. However, omega−3 fatty acid supplementation greater than one gram daily for at least a year may be protective against cardiac death, sudden death, and myocardial infarction in people who have a history of cardiovascular disease. No protective effect against the development of stroke or all-cause mortality was seen in this population. Eating a diet high in fish that contain long chain omega−3

title: Omega-3 fatty acid
text: fatty acids has an effect on different cancers. The effect of consumption on prostate cancer is not conclusive. There is a decreased risk with higher blood levels of DPA, but an increased risk of more aggressive prostate cancer was shown with higher blood levels of combined EPA and DHA. In people with advanced cancer and cachexia, omega−3 fatty acids supplements may be of benefit, improving appetite, weight, and quality of life. Evidence in the population generally does not support a beneficial role for omega−3 fatty acid supplementation in preventing cardiovascular disease (including myocardial infarction and sudden cardiac death) or stroke.

title: Dietary supplement
text: affect the risk of death, cancer or heart disease. Furthermore, studies of fish oil supplements have failed to support claims of preventing heart attacks or strokes. In 2017, the American Heart Association issued a science advisory stating that it could not recommend use of omega-3 fish oil supplements for primary prevention of cardiovascular disease or stroke, although it reaffirmed supplementation for people who have a history of coronary heart disease. Dietary supplements can be manufactured using intact sources or extracts from plants, animals, algae, fungi or lichens, including such examples as ginkgo biloba, curcumin, cranberry, St. John’s wort, ginseng, resveratrol,

title: Cattle feeding
text: fats, it can replace other protein-dense foods such as soy. It is believed that the inclusion of omega-3 fatty acids in the diets of beef producing cattle will bring an increase in health to the animals and to the quality of carcass upon slaughter. Some studies have found that feeding flax seeds may increase the omega-3 content and improve marbling in the carcass of the animal at slaughter while others have found no differences. Flax seeds suppress inflammatory effects from bovine respiratory disease (BRD) often affecting stressed cattle due to production practices such as transport and processing. BRD can lead

title: Polyunsaturated fat
text: walnut oil. These oils are used to make paints and varnishes. In preliminary research, omega-3 fatty acids in algal oil, fish oil, fish and seafood have been shown to lower the risk of heart attacks. Other preliminary research indicates that omega-6 fatty acids in sunflower oil and safflower oil may also reduce the risk of cardiovascular disease. Among omega-3 fatty acids, neither long-chain nor short-chain forms were consistently associated with breast cancer risk. High levels of docosahexaenoic acid (DHA), however, the most abundant omega-3 polyunsaturated fatty acid in erythrocyte (red blood cell) membranes, were associated with a reduced risk of

title: Fish oil
text: Allergies, supplementation of 5 grams of EPA and DHA combined does not pose a safety concern for adults. Dyerberg studied healthy Greenland Inuit and found an average intake of 5.7 grams of omega-3 EPA per day; among other effects these people had prolonged bleeding times, i.e., slower blood clotting. The liver and liver products (such as cod liver oil) of fish and many animals (such as seals and whales) contain omega-3, but also the active form of vitamin A. At high levels, this form of the vitamin can be dangerous (Hypervitaminosis A). Consumers of oily fish should be aware of

title: Fish oil
text: detoxifying organ, PCB content may be higher in liver-based oils than in fish oil produced from the processing of whole fish. An analysis based on data from the Norwegian Women and Cancer Study (NOWAC) with regards to the dangers of persistent organic pollutants (POPs) in cod liver came to the conclusion that "in Norwegian women, fish liver consumption was not associated with an increased cancer risk in breast, uterus, or colon. In contrast, a decreased risk for total cancer was found." A report by the Harvard Medical School studied five popular brands of fish oil, including Nordic Ultimate, Kirkland and

title: Omega-3 fatty acid
text: omega−3 fatty acids, EPA (20 carbons and 5 double bonds) and then from EPA, the most crucial, DHA (22 carbons and 6 double bonds). The ability to make the longer-chain omega−3 fatty acids from ALA may be impaired in aging. In foods exposed to air, unsaturated fatty acids are vulnerable to oxidation and rancidity. Supplementation does not appear to be associated with a lower risk of all-cause mortality. The evidence linking the consumption of marine omega−3 fats to a lower risk of cancer is poor. With the possible exception of breast cancer, there is insufficient evidence that supplementation with omega−3

title: Omega-6 fatty acid
text: omega-3 helped reduce inflammation in patients with rheumatoid arthritis. A ratio of 5 had a beneficial effect on patients with asthma but a ratio of 10 had a negative effect. A ratio of 2.5 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4 had no effect. Excess omega-6 fatty acids from vegetable oils interfere with the health benefits of omega-3 fats, in part because they compete for the same rate-limiting enzymes. A high proportion of omega-6 to omega-3 fat in the diet shifts the physiological state in the tissues toward the pathogenesis of many diseases:

title: Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective
text: processed foods tends to help reduce the risk of cancer. Foods that are typically low in calorie density tend to contain higher amounts of healthy fiber and water content. Plant Foods: Eat mostly foods of plant origin Animal Foods: Limit intake of red meat and avoid processed meat. According to the Report in reducing cancer risks, people should not consume more than 18 ounces or 500 grams (cooked weight) per week of red meats. Heme iron is a compound that gives red meat its color. If consumed in very high amounts, it has been shown to damage the colon lining.

title: Fish oil
text: such as salmon, herring, mackerel, anchovies, and sardines. Oils from these fish have a profile of around seven times as much omega-3 oils as omega-6 oils. Other oily fish, such as tuna, also contain omega-3 in somewhat lesser amounts. Although fish is a dietary source of omega-3 oils, fish do not synthesize them; they obtain them from the algae (microalgae in particular) or plankton in their diets. For comparison, note the omega-3 levels in some common non-fish foods: In a 2009 letter on a pending revision to the Dietary Guidelines for Americans, the American Heart Association recommended 250–500 mg/day of

title: Cancer prevention
text: between fruits and vegetables and cancer. Consumption of coffee is associated with a reduced risk of liver cancer. Studies have linked excessive consumption of red or processed meat to an increased risk of breast cancer, colon cancer, and pancreatic cancer, a phenomenon which could be due to the presence of carcinogens in meats cooked at high temperatures. Dietary recommendations for cancer prevention typically include an emphasis on vegetables, fruit, whole grains, and fish, and an avoidance of processed and red meat (beef, pork, lamb), animal fats, and refined carbohydrates. Research shows that regular physical activity helps to reduce up to

title: Breast cancer
text: encourage regular physical activity and reduce obesity could also have other benefits, such as reduced risks of cardiovascular disease and diabetes. High intake of citrus fruit has been associated with a 10% reduction in the risk of breast cancer. Marine omega-3 polyunsaturated fatty acids appear to reduce the risk. High consumption of soy-based foods may reduce risk. Removal of both breasts before any cancer has been diagnosed or any suspicious lump or other lesion has appeared (a procedure known as "prophylactic bilateral mastectomy" or "risk reducing mastectomy") may be considered in people with BRCA1 and BRCA2 mutations, which are associated