You’ve heard—perhaps many times over—that omega-3 fatty acids are essential to good health, and solid research supports some heart-protective attributes. But it can be a challenge to get enough in one’s diet. While omega-3 supplements, often made from fish oil, offer to simplify the task, those products aren't necessarily as good an alternative. “To some extent, the public views supplements as something other than medication, but [a supplement] is medication,” says David Siscovick, codirector of the Cardiovascular Health Research Unit at the University of Washington in Seattle, who has long studied heart disease prevention.
The American Heart Association recommends that everyone get optimal omega intake by eating a variety of fish at least twice a week and consuming plant sources of omega-3 as well. The AHA places particular emphasis on the omega-3 heavy hitters, the fatty fish. For people with coronary heart disease, the AHA recommends up to 1 gram total of EPA and DHA—two forms of omega-3—per day, “preferably from fatty fish.” Omega-3 capsules, according to the AHA, could be considered in consultation with a physician. And for those who need to lower their triglycerides, the AHA calls for 2 to 4 grams per day by capsule, under a physician’s direction; such high intake could lead to excessive bleeding in certain people.
Some experts think that other groups of patients should also be encouraged to take omega-3 supplements. A paper published this month in the Journal of the American College of Cardiology, for example, suggests that heart failure patients should be getting the daily gram of combined EPA and DHA that the AHA currently recommends for coronary heart disease patients. The paper's authors review some of the major research on omega-3s, discuss dietary sources, and tout a long list of potential clinical uses of the healthful fats in cardiovascular patients. Carl Lavie, lead author and medical director of cardiac rehabilitation and prevention at Ochsner Heart and Vascular Institute in New Orleans, says he wrote the paper because he believes that while the average doctor, or even heart doctor, recognizes omega-3s as “a healthy thing,” many don’t realize the extent to which the fatty acids' benefits have been studied.
The paper puts an emphasis on omega-3 supplements. And Lovaza, a prescription omega-3 pill approved by the Food and Drug Administration to treat very high triglycerides, gets five mentions in the paper, something Siscovick says is “quite unusual for a scientific article.” Lavie and two of his three coauthors on the paper have disclosed ties to GlaxoSmithKline, maker of Lovaza. (Siscovick himself is an unpaid member of a scientific advisory committee on a GSK-funded study of fish oil supplements and has consulted to other drug companies.) Lovaza contains high doses of omega-3s; a prescription might be for 4 grams per day, for example. Siscovick warns that taking a high dose of any medicine is not necessarily better than taking a lower dose.
Siscovick, who conducted some of the research that the new paper summarizes, says the paper may overstate some of the powers of omega-3s. “The clinical trials that are positive are given more weight than those that are negative,” he says. For example, the paper suggests that omega-3s have a beneficial effect on atherosclerosis, or buildup of plaque in the arteries, Siscovick says. “I think that’s very questionable.” As for expanding the range of medical conditions against which omega-3s supplements—or Lovaza—could be wielded, he says, “I just don’t think the evidence is there yet.”
So what does this all mean for the majority of Americans? “Modify diet rather than [taking] prescription Lovaza or stocking up on vitamins,” says Siscovick, who thinks the AHA recommendations are appropriate. Siscovick points to the twice-weekly regimen of fatty fish as a do-able task.
Lavie, however, says that following the AHA's recommendation for people with coronary heart disease is tough to do through diet alone, requiring at least four servings of fish per week, he estimates. “To get protective amounts, most people are going to have to take a supplement,” Lavie says, noting that a lot of his patients' main type of fish is catfish, which isn’t particularly high in EPA or DHA. “I want to promote the principle,” he says. “I don’t want to promote a certain product.”