The tides are turning for fish oil, at least when it comes to usefulness of supplements in staving off heart attacks and stroke.

After a lot of initial excitement over omega-3 fatty acids, which are found in oily fish such as salmon and sardines, Greek researchers today released the latest study to find the substances won’t help you dodge heart disease - whether you get them from supplements or your diet.

Based on a review and analysis of previous clinical trials including more than 68,000 participants, they found omega-3 supplements had no impact on overall death rates, deaths from heart disease, or stroke or heart attacks.

Dr. Donna Arnett, the president of the American Heart Association, told Reuters Health the new analysis is the largest to date. She said it closes the issue of omega-3’s role in heart disease, showing the “supplements are of no benefit” whether or not a person has had previous heart problems.

The AHA does recommend omega-3 supplementation against high levels of triglycerides (a type of fat in the blood) - a condition the fish-oil pills have been approved to treat by U.S. health regulators.

The new study, published in the Journal of the American Medical Association, pools the results of 18 clinical trials that assigned participants randomly to take either omega-3 supplements or not. It also includes two trials in which people got dietary counseling to increase their consumption of omega-3- rich foods.

The average daily dose of omega-3 taken was 1.51 grams per day and included eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

A decade ago, the available medical evidence suggested that boosting omega-3 with food or supplements had a strong protective effect. Although the potential mechanism wasn’t understood, scientists cited improvements in triglyceride and blood pressure levels and heart rhythm disturbances.

But since then, the picture has grown increasingly clouded. Earlier this year, a group of Korean researchers found that omega-3 supplements had no effect on heart disease or death based on 20,000 participants in previous trials.

Because the trials included in the Greek analysis went as far back as 1989, the researchers also considered whether growing use of statins and other medications could explain why later studies failed to support the early findings.

But according to the team, led by Dr. Mosef Elisaf at the University Hospital of Ioannina, that wasn’t the case.

“I think the bottom line is supplements are not always the answer,” said Alice Lichtenstein, director of the Cardiovascular Nutrition Laboratory at Tufts University in Boston.

Because people who eat a lot of fish have been found to have less heart disease, she told Reuters Health, researchers figured that perhaps putting the supposed “active ingredients” in a pill could provide similar benefits.

“Once again we found that is not the case,” Lichtenstein said. “What we have learned over the years is you can’t think about individual nutrients in isolation.”

People who eat fish often may be replacing things like steak, hamburgers or quiche, making for a healthier diet overall.

Instead of taking supplements, Lichtenstein recommended helping your heart by eating fish at least twice a week, having a diet rich in whole grains and vegetables, getting lots of physical activity and not smoking.

SOURCE: Journal of the American Medical Association, online September 11, 2012