Will Fish Oil Supplements Make You Smarter Or Prevent Heart Disease?

Nearly 1 in 10 Americans uses a fish oil supplement regularly making it one of the most popular supplements in the U.S., say researchers at the National Center for Health Statistics. Americans spend more than $1 billion each year on fish oil. Many hope the supplements will improve joint health, sharpen the mind and prevent heart disease and strokes. But data about the health benefits of fish oils is inconsistent and often inconclusive.Fish oils contain two types of omega-3 fatty acids called EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid). Our bodies can’t make these fatty acids so we have to consume them. Good sources of EPA and DHA are oily fish such as mackerel, herring and sardines. Some non-animal foods, such as pumpkin seeds and walnuts, contain a different kind of omega-3 fatty acid, alpha-linolenic acid, which the body converts to DHA and EPA. These fatty acids are transformed by the body into anti-inflammatory chemicals called resolvins.Omega-3 fatty acids have been touted as preventing heart disease since at least the 1970s when researchers postulated that Inuit people in Canada and Alaska had lower rates of heart disease because they ate a diet rich in fish. That theory was later debunked and researchers said the Inuit probably have more heart disease than the earlier scientists accounted for. But claims about fish oil supplements have persisted.The data, however, is unclear. I read through nearly 30 studies on fish oils published in the last eight years and found only two that showed the supplements were better than placebo at improving the health of those that took them.There is some evidence that oily fish and fish oil supplements may ease the pain and swelling of rheumatoid arthritis. One study found that users had less joint pain in the morning and reported that their joints felt less tender. But many studies looking at the effects on rheumatoid arthritis were small and involved users taking multiple supplements. Other studies looked at the effect of fish oils on blood pressure. While some reported the supplements lowered blood pressure, these also were small studies. Other studies found that fish oils had no impact on blood pressure. There is better evidence that fish oils lower triglyceride levels but some of these studies relied on high doses - up to 4 grams per day - and on combining fish oils with other medicines such as statins. Prescription fish oil supplements containing high doses of omega-3 fatty acids have been approved by the Food and Drug Administration but these can cause side effects such as prolonged bleeding. After a safety review of fish oils in 1997, the FDA said that people should take no more than 3 grams of EPA and DHA per day. Side effects of taking fish oils at high doses range from the annoying - nausea and a fishy burp - to the dangerous - prolonged bleeding caused by a disruption in the clotting system.  Continue reading...