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.
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.