Harvard Men's Health Watch

Fish oil for the heart

Q. Should I take fish oil supplements for my heart? I've heard it helps people who have already had heart attacks.

A. More than 50 years ago, scientists observed that people with diets high in omega-3 fatty acids (found primarily in oily fish such as salmon, herring, and mackerel) had low rates of cardiovascular disease. Omega-3 fatty acids include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These substances produce beneficial effects on the blood vessels, triglyceride levels, and blood clotting.

However, research so far has not shown that taking fish oil supplements provides the same benefit as eating fish. For example, three recent trials failed to show that fish oil supplements reduce the risk of death and heart attack in patients with established heart disease. Furthermore, no medical research proves fish oil supplements prevent initial heart attacks in otherwise healthy men.

Even though fish oil supplements have, so far, failed to live up to their earlier promise, there may be other substances in oily fish that provide a benefit in addition to the EPA and DHA they contain. Consuming one to two servings of fish per week has been associated with lower heart risk. Although there are other promising benefits of fish oil supplements, such as treatment of depression and prevention of dementia, further research is needed before recommendations can be made about taking fish oil supplements.

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