Eating more heart-healthy omega-3 fats provided no additional benefit in a study of heart attack survivors who were already getting good care, Dutch researchers report.
After nearly 3 1/2 years, there was no difference in deaths, heart attacks and other heart problems between those who ate margarine with added omega-3 fatty acids and those who didn’t, the study found.
The results don’t mean that getting more of the essential nutrient has no value. Several studies have offered evidence that the fats — mostly from fish oil — reduce heart disease.
But for heart patients who are carefully treated “adding a little bit of omega-3 fatty acid does not seem to make a difference,” said Alice Lichtenstein, a Tufts University nutrition professor, who was not involved in the research.
Omega-3 fatty acids are thought to help reduce the risk of abnormal heartbeats, slow the growth of plaque that can clog arteries and lower harmful fats called triglycerides.
In recent years, omega-3 has been added to some foods such as margarine and eggs, or labels highlight the omega-3 content of foods like tuna fish.
“Now they’re popping up in the most unexpected places,” including trail mix, said Lichtenstein.
Two kinds of omega-3s come from wild oily fish such as salmon, mackerel and tuna. A third type comes from plants; sources include walnuts, flaxseed, soybeans and canola oil.
It’s generally recommended that people eat one or two servings of fish a week, said the study’s leader, Daan Kromhout of Wageningen University in the Netherlands.
“The results of this trial do not change that,” he said, noting that there were no harmful side effects. “It’s still a good thing to eat fish once or twice a week.”
The study’s participants were taking the best medicines to prevent future heart trouble, and that could be why adding a low-dose of omega-3s offered no extra protection, the researchers said. The volunteers were also older and entered the study years after their heart attacks, in contrast to heart patients in earlier research who did benefit by taking fish oil pills.
The findings were presented Sunday at the European Society of Cardiology meeting in Stockholm and published online by the New England Journal of Medicine.