Fish oil supplements don't help prevent heart disease or heart attacks, even for people at high risk.

That’s the conclusion of an extensive analysis published today in JAMA Cardiology, which found no evidence to support the use of these supplements for heart health. The study was based on data from nearly 78,000 people worldwide.

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The new research "gives clarity that fish oil supplements do not have benefits for the heart," says Robert Clarke, M.D., an epidemiologist at the University of Oxford, who led the study.

These results "come as no surprise,” says Marvin M. Lipman, M.D., Consumer Reports’ chief medical adviser. “There’s so much hype surrounding these supplements, but not much evidence to back up the claims.”

More than 20 percent of Americans take fish oil supplements, according to a 2015 survey by the Consumer Reports National Research Center. Here’s what you need to know about the new finding, and why you should skip the supplements and just eat fish instead.  

What the Study Found

The new study amassed data from 10 clinical trials that included a total of 77,917 people (average age: 64) who took fish oil supplements for an average of 4.4 years.

Whether the authors looked at all of those people together or broke them into subgroups (for example, diabetics, or people with prior heart disease), they could find no link between taking supplements and reducing risks.

"Studies that have showed really dramatic results [from fish oil supplements] often had small sample sizes, or employed methods that could lead to patient bias," says Clarke, the study's author. The new analysis only included clinical trials that involved at least 500 people.

A statement attributed to Duffy MacKay, N.D., the senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition, a group that represents the supplements industry, said that fish oil supplements should still be considered part of a heart-healthy lifestyle—but that consumers should "manage their expectations for the role that dietary supplements, such as omega-3 fatty acids, can play in reducing the risk of cardiovascular disease."

The new findings largely affirm a report from last year by the American Heart Association (AHA), which also found almost no connection between fish oil supplements and heart disease prevention. The AHA report did find, however, that among people who had already suffered a heart attack or heart failure, fish oil supplementation was linked to a slight (10 percent) drop in the risk of dying from heart disease.

That seemingly positive glimmer shouldn't carry too much weight, though, says David Siscovick, M.D., senior vice president for research at the New York Academy of Medicine, who led the committee behind the AHA report. It might have been the result of the way the researchers analyzed the data, he explains, or the way the questions about fish oil use and heart health were posed to patients.

“Our conclusions are basically the same,” Siscovick says. “We see no evidence to recommend prescribing fish oil supplements for heart health for the general public.”* 

What About Fish?

The Food and Drug Administration (FDA) doesn't require manufacturers of over-the-counter supplements to prove that their products, including fish oil supplements, are safe and effective before putting them on store shelves, so it’s hard to know exactly what they contain.

As Consumer Reports has previously documented, fish oil supplements, as with any supplement, might contain unknown adulterants. If you're considering taking a supplement anyway, be sure to check with your physician first, says Lipman.

But fatty fish itself, such as salmon and sardines, is a healthy choice and a good way to get your omega-3 fatty acids, along with lean protein and other nutrients, experts say. The American Heart Association recommends eating two 3½-ounce portions of fish per week.

“Our studies only looked at supplements, and I want to make it clear that we are not discouraging people from eating fish,” Siscovick says. “There are many health benefits you don’t get from taking the pills.”  

*Editor's Note: When this article first published, this quote did not include "for the general public." Siscovick followed up with CR to note that the slight benefits associated with fish oil that were shown in the earlier AHA report—among those who already had a heart attack or heart disease—could potentially lead to a physician recommendation for that group.