Aug. 30, 2010 (Stockholm, Sweden) -- Margarine fortified with omega-3 fatty acids does not appear to protect older men and women who have survived a heart attack from having another heart attack or other cardiac event.
That's the bottom line of the ALPHA-OMEGA trial of 4,837 heart attack survivors, aged 60 to 80, who spread the enriched margarine on their bread for more than 40 months.
The participants were divided into four groups. One got margarine supplemented with low doses of the fatty acids DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which are found in fish oil.
Another had their spread enriched with alpha-linolenic acid (ALA), derived from soybean oil and walnuts. A third group received margarine fortified with all three fatty acids; the rest got a placebo margarine.
By the study's end, 14% of the heart attack survivors had experienced another cardiac event, including fatal or nonfatal heart attacks or a cardiac intervention such as angioplasty, regardless of which spread they used.
Possible Benefits for Women
There was a hint of benefit among women who ate the ALA-fortified margarine. They were about 25% less likely to suffer a major cardiac event than other participants, but the finding could have been due to chance.
Omega-3 fatty acid-enriched margarines "had no effect on the rate of major cardiovascular events," says researcher Daan Kromhout, PhD, MPH, of Wageningen University in the Netherlands.
About three-fourths of participants were men and 24% were obese.
Kromhout says that one possible explanation for the findings is that "the patients in this trial were very well treated," with the vast majority taking medications to control blood pressure and cholesterol.
Their excellent cardiovascular care makes "a beneficial effect of low doses of EPA-DHA difficult to prove," he tells WebMD.
Participants received a daily dose of 2 grams of ALA or 400 milligrams of EPA and DHA -- the latter being half the dose recommended by the American Heart Association, Kromhout says.
He reported the findings at the European Society of Cardiology Congress. They were simultaneously published online by the New England Journal of Medicine.
Fish Is Best for Omega Fatty Acids
American Heart Association spokeswoman Mariell Jessup, MD, medical director of the Penn Heart and Vascular Center at the University of Pennsylvania, tells WebMD that the best way to get your omega fatty acids is to eat two to three servings of fish a week.
In the study, participants spread 20 grams of the trial margarine on three to four slices of bread a day.
The margarines used in the trial were supplied by Unilever. In a statement, the company said the "study outcome for EPA and DHA is surprising considering the weight of evidence published to date. This could be the result of methodological issues such as the relatively low daily dosage compared with previous studies or the fact that in this study serious cardiovascular events were much lower than in studies performed in the past. "