Most of us don’t need fish oil supplements

By Dr. Howard LeWine
Posted on November 14, 2018

Q: I am not a big fish eater. Should I be taking a fish oil supplement?

A: People who regularly eat fish, especially fatty fish like salmon, herring, mackerel and sardines, have lower rates of heart attack and stroke. The health benefits of fatty fishes likely relates to their high content of two of the omega-3 polyunsaturated fatty acids, EPA and DHA.

The reason for the lower risk of cardiovascular disease is attributed to two important biologic properties of EPA and DHA. These unique fats ease inflammation and help prevent blood clots, two key underlying causes of heart attacks and strokes.

But does taking the oil out of fish and putting it in a capsule provide the same positive health effects? As with many treatments in medicine, it depends.

Fish oil supplements are an effective treatment to lower blood triglyceride levels. If this is your main goal, it’s best to ask your doctor whether you should take a prescription product rather than one you buy over-the-counter.

For people with a history of heart attack or heart failure, taking a fish oil supplement may slightly lower the risk of having another heart attack or needing hospitalization.

That’s it. For everyone else, the science does not support the use of omega-3 fatty acid supplements to improve health.

Even for people prone to cardiovascular disease — including those with diabetes, atrial fibrillation or history of stroke — there is no evidence that taking fish oil supplements offers any benefit.

Since you are not a fish eater, you can get another type of healthy omega-3s, known as ALA, from plant foods. Our bodies can convert a small amount of ALA to EPA.

Rich sources of ALA include flaxseed, walnuts, pumpkin seeds, and soybean or canola oil. Green vegetables such as Brussels sprouts, spinach and kale also contain ALA.

Howard LeWine, M.D., is an internist at Brigham and Women’s Hospital in Boston and assistant professor at Harvard Medical School. For additional consumer health information, please visit www.health.harvard.edu.