Margarine enriched with omega-3 oils make no difference to having a repeat heart attack in patients with a history of heart problems.
More than 4,800 patients across a 40-month study showed taking low doses of omega-3 fatty acids in margarine did not significantly reduce rates of serious heart attacks and other cardiovascular events.
Previous studies had suggested omega-3 helped hearts stay healthy and the margarines used in the study were developed for the Dutch researchers by Unilever, a food and consumer goods giant.
However, doctors are unlikely to change clinical practice because a large number already prescribe omega-3 fish oil capsules to reduce triglycerides, a type of blood fat linked to blocked arteries.
“It will be viewed as a largely negative study”, said Scott Wright of the Mayo Clinic in the US, who was not involved in the study, “and people who are enthusiasts for omega fatty acids will continue to be enthusiasts and people who are skeptics will continue to be skeptics”.
Daan Kromhout of Wageningen University, who led the study, argued the lack of efficacy could be a result of the drug treatment patients were receiving as well as the margarines.
A total of 85 percent participants were also on cholesterol-lowering statins in addition to blood pressure and blood-thinning tablets.
“We found the cardiovascular mortality rate in the study population was only half that expected”, he said, “probably because of their excellent treatment”.
All the male and female participants in the Dutch study were aged between 60 and 80 and had suffered a heart attack approximately four years beforehand.
