By Lisa Ellis
InteliHealth News Service

CHICAGO — People with coronary heart disease should eat fish at least once a day or take supplements containing certain components of fish oil, the American Heart Association (AHA) says in a newly updated statement.

People who have high triglycerides should consume two to four times as much of these fish oil components, known as DHA and EPA, the statement says. That amount almost certainly would have to be given as a supplement, and should be taken only under a doctor's care, the AHA says.

The statement was released during a news conference at the AHA's annual Scientific Sessions. It is being published in the Nov. 19, 2002, issue of Circulation, an AHA journal.

The policy statement continues a two-year-old recommendation that all adults eat a variety of fish, especially fatty fish such as salmon and mackerel, at least twice a week.

It also recommends consuming flaxseed, walnuts, flaxseed and walnut oils, soybean oil and canola oil.

Fish and these plant-derived oils all contain omega-3 fatty acids, which studies have shown reduce the risk of cardiovascular disease. But the greatest benefits have been shown for the types of omega-3 fatty acids in fish, specifically DHA and EPA.

If possible, DHA and EPA should come from fish because it also provides protein, vitamins and minerals, said Penny M. Kris-Etherton, Ph.D., a dietician and member of the AHA nutrition committee that wrote the guidelines. People who eat fish also may be less likely to red meat or fatty dairy products, she said. These contain saturated fat, which can increase the risk of heart disease.

But Kris-Etherton acknowledged that some people cannot or will not eat fish, or can't get enough from food to meet their needs because of heart disease or high triglycerides. Therefore, the AHA is recommending for the first time that these groups consider supplements, in consultation with a doctor.

"We're driven [to that position] by the evidence," said William S. Harris, Ph.D., another committee member. He referred to several well-designed studies in recent years that have strengthened the case that omega-3 fatty acids — in fish or in supplements — help to prevent heart disease.

Some studies have shown reductions of 20 percent to 30 percent in overall and heart-related death rates for people who consume fish or supplements.

Various studies of fish or supplements showed a 4 percent to 30 percent reduction in triglycerides, but a doctor's care is advised because large doses can present a risk of bleeding in some people, according to the AHA statement.

People can get the recommended 1 gram per day of DHA and EPA combined by eating a 3- to 4-ounce serving of fatty fish such as salmon, mackerel, herring, trout or white tuna, according to a chart published with the statement in Circulation. Larger quantities are needed for other kinds of fish.

Harris said people who take supplements should read the labels and make sure they are getting at least 1 gram of DHA and EPA. With a typical supplement, you need about three capsules to get this amount, he said.

Researchers are still trying to sort out exactly how omega-3 fatty acids protect against heart-disease death.

AHA president Robert Bonow, M.D., said some evidence indicates that they may guard against irregular heart rhythms, a common cause of sudden death. They also may reduce clumping of platelets in the blood, which can produce clots and cause heart attacks, he said.

The AHA statement notes that the U.S. Food and Drug Administration and Environmental Protection Agency recommend restrictions on consumption of certain fish for young children, pregnant and nursing women because of concerns about mercury contamination.

Harris said this should not be a significant concern for most people in the AHA's target audience because those most likely to be harmed by low doses of mercury — fetuses and young children — are least likely to get heart disease. "The concern about mercury for adults is pretty much a non-event in our view," he said.

The Environmental Protection Agency, which regulates sport fishing, recommends that pregnant or nursing women and those who may become pregnant eat only one 6-ounce serving of sport-caught fish per week. It recommends less than 2 ounces of sport fish per week for young children.

The Food and Drug Administration, which regulates commercial fishing, advises women who are pregnant or nursing and young children to avoid eating shark, swordfish, king mackerel and tilefish (also called golden bass or golden snapper). It also recommends that these groups eat no more than 12 ounces a week of other fish to minimize mercury exposure.

People outside these groups may safely eat up to 7 ounces weekly of the higher-mercury fish and 14 ounces of fish with moderate levels, including fresh tuna, orange roughy, marlin and red snapper, the Food and Drug Administration says.

Kris-Etherton said eating fast-food or frozen breaded fish fillets will not meet the need for omega-3 fatty acids because these dishes are made with non-fatty fish. She said they also are typically deep-fried in unhealthy oils or shortening.

The AHA recommends low-fat cooking methods such as broiling, baking and poaching, she said.