A new scientific advisory report from the American Heart Association (AHA) concludes that omega-3 fish oil supplements, which have long been touted as a path to heart health, may not be useful as a heart disease preventive.

According to the new report, published in the journal Circulation, only heart attack survivors and those who have already been diagnosed with heart failure seemed to benefit from taking the supplements. Meanwhile, other evidence supports the benefits of eating fish—such as salmon and sardines—for protecting against heart disease. 

About 21 percent of Americans take fish oil supplements, according to a 2015 nationally representative survey of more than 2,000 people from the Consumer Reports National Research Center. This new AHA report suggests that many of them probably aren’t getting the protective benefits they’re banking on.

“The bottom line is that there are many people who are taking fish oil supplements for no good reason,” says Marvin M. Lipman, M.D., Consumer Reports’ chief medical advisor.

Fish Oil Pills for Heart Attacks

The AHA reviewers looked at 13 randomized clinical trials (considered the gold standard for research) that looked at fish oil supplementation and its possible role in the prevention and treatment of cardiovascular events—including strokes and heart attacks.

“In people who do not have heart disease, there is no evidence that fish oil supplements show any benefit for preventing heart attack, stroke, or heart failure,” says David Siscovick, M.D., senior vice president for research at the New York Academy of Medicine and chair of the writing committee for the advisory.

However, the evidence does show that for those who have already experienced a heart attack or been diagnosed with heart failure, taking a daily dose of 1,000 mg of omega-3 fatty acids from fish oil supplements may reduce the risk of dying from heart disease by 10 percent, Siscovick says.

The omega-3 fats in fish oil may help reduce the risk of arrhythmias (abnormal heartbeats), which can lead to sudden death,  lower triglyceride levels, slow the growth of atherosclerotic plaque, and reduce blood pressure slightly, according to the AHA.


Skip Pills Altogether?

Some medical experts question the use of fish oil supplements for anyone—including those who already have heart disease. Says

“The evidence supporting them [fish oil supplements]  is weak and conflicting—with some of the studies the panel analyzed showing benefit and others not,” says Steven Nissen, M.D., chairman, department of cardiovascular medicine, at the Cleveland Clinic. 

Another concern is that the Food and Drug Administration (FDA) does not require over-the-counter supplement manufacturers to prove their products are safe and effective before putting them on store shelves.

“I do not recommend people take fish oil supplements or other dietary supplements for the most part because they are unregulated,” says Nissen.

Most of the trials the researchers analyzed for the AHA report used prescription--not over-the-counter fish oil supplements (there are currently five FDA-approved ones on the market), and the new guidelines also recommend doctor-prescribed pills—not the over-the-counter versions. 

"Ideally people should strive to eat a diet high in fatty fish...in order to obtain omega-3 fatty acids, but realistically, as data show, most people are not doing this," says Andrea Wong, Ph.D., vice president, scientific and regulatory affairs at the Council for Responsible Nutrition, the leading supplement industry trade group says.

"If you do not eat fatty fish on a regular basis," Wong adds, "supplementing with omega-3s, along with eating a healthy diet and exercising, is a viable option for maintaining a healthy heart and for the other benefits the omega-3 supplements can provide."

Fish vs. Fish Oil Supplements

One thing most heart disease experts do agree on: The best way to get the protective benefits of omega-3s is to eat fish rather than take fish oil supplements.  

Salmon, sardines, mackerel, and other fatty fish, have the highest amount of omega-3s, and are low in mercury. Fish may be protective, says Lipman, not just because of its omega-3 content, but because it is a lean source of protein, low in saturated fat, and rich in other nutrients.

The AHA recommends that everyone eat two 3 ½ ounce servings of fish per week, to keep their heart healthy. Finally, Lipman advises that anyone who wants to take fish-oil supplements first discuss the pros and cons with their doctor.