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National Center for Complementary and Integrative Health

5 Things To Know About Omega-3s for Heart Disease

Omega-3 fatty acids are a group of polyunsaturated fatty acids that are important for a number of functions in the body. They are found in foods such as fatty fish and certain vegetable oils and are also available as dietary supplements. While experts agree that fish rich in omega-3 fatty acids should be included in a heart-healthy diet, there isn’t conclusive evidence that shows omega-3s have a protective effect against heart disease.

  1. Experts agree that fish rich in omega-3 fatty acids should be included in a heart-healthy diet. Much research has been done on fish and heart disease, and the results provide strong, though not conclusive evidence that people who eat fish at least once a week are less likely to die of heart disease than those who rarely or never eat fish.

  2. Omega-3s in supplement form have not been shown to protect against heart disease. While there has been a substantial amount of research on omega-3 supplements and heart disease, the findings of individual studies have been inconsistent. In 2012, two combined analyses of the results of these studies did not find convincing evidence that omega-3s protect against heart disease.

  3. Omega-3 supplements may interact with drugs that affect blood clotting. Omega-3 supplements may extend the time it takes for a cut to stop bleeding. People who take drugs such as anticoagulants (“blood thinners”) or nonsteroidal anti-inflammatory drugs should discuss the use of omega-3 fatty acid supplements with a health care provider.

  4. Fish liver oils (which are not the same as fish oils) contain vitamins A and D as well as omega-3 fatty acids; these vitamins can be toxic in high doses. Fish liver oils contain vitamins A and D as well as omega-3 fatty acids. Both of these vitamins can be toxic in large doses. The amounts of vitamins in fish liver oil supplements vary from one product to another.

  5. Talk to your health care provider before using omega-3 supplements. If you are pregnant or nursing a child, if you take medicine that affects blood clotting, if you are allergic to fish or shellfish, or if you are considering giving a child an omega-3 supplement, it is especially important to consult your (or your child’s) health care provider.