Do Fish Oil Supplements Prevent Heart Attacks or Strokes?

National Center for Health Research

Fish oil supplements are very popular, and the American Heart Association (AHA) recommends taking fish oil capsules to prevent a second heart attack or stroke (this is also known as “secondary prevention”). However, a January 2018 meta-analysis, published in the prestigious medical journal JAMA Cardiology, concluded that patients who have heart disease, including those who have had a prior heart attack or stroke do not benefit from fish oil supplements.1 The analysis showed that taking the supplements do not decrease the chances of having a heart attack or stroke, dying from a heart attack or stroke, or dying from any other cause. A meta-analysis is a type of study that combines data from many smaller studies to try to draw conclusions based on more patients.  In this case, the studies included almost 80,000 patients with coronary heart disease, stroke, or diabetes who were followed for about 4 years while taking fish oil supplements or a sugar pill (placebo).

When there are conflicting recommendations like this, it is not always possible to make sense of them.  However, experts believe that because most patients in the meta-analysis were already taking many other kinds of heart medications, the researchers did not see an additional benefit from fish oil supplements. Therefore, it is possible that patients who are not being treated with other heart medications could benefit from taking fish oil. More research is needed to find out if that is true.

The Bottom Line: If you have had a heart attack or stroke, fish oil supplements will probably do little if anything to protect you from having another or dying from one. However, the American Heart Association is continuing to recommend the supplements for patients who previously had a heart attack or stroke, but not for the general public. The AHA also continues to recommend eating two 3.5-ounce servings of non-fried fish, or about ¾ cup of flaked fish every week.2 They emphasize that the healthiest fish are oily fish like salmon, mackerel, herring, lake trout, sardines or albacore tuna, which are all high in omega-3 fatty acids.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.


[1] Abbasi J. Another Nail in the Coffin for Fish Oil Supplements. JAMA. 2018;319(18):1851–1852. doi:10.1001/jama.2018.2498 available online:

[2] Keep Saying Yes to Fish Twice a Week for Heart Health, American Heart Association Scientific Advisory, May 17, 2018,