Millions of people take fish oil supplements and the American Heart Association recommends eating at least two servings of fish a week and that people with a history of heart disease take omega-3 fatty acids supplements. However, a new analysis, in JAMA Cardiology has found that supplements containing omega-3 fatty acids, the oils abundant in fatty fish, are ineffective for prevention of heart disease.
The new meta-analysis pooled data from 10 randomized trials with a total of 77,917 participants who had either had cardiovascular disease or were at high risk for it. The average age of participants when they joined the trials was 64 years and average duration of treatment was 4.4 years. Participants were randomly assigned to take either omega-3 fatty acid supplements (dose range in different trials: 226 to 1,800 milligrams/ day) or placebo.
During follow up, 2,695 people (3.5%) died from heart disease, 2,276 (2.9%) had non-fatal heart attacks, 1,713 (2.2%) had strokes, 6,603 (8.5%) had procedures to reopen clogged arteries and 12,001 (15%) had any major cardiovascular event. Treatment with omega-3 fatty acid supplements had no significant effect on any of these cardiovascular diseases.
Professor Robert Clarke, senior author of the study said “The results of this meta-analysis of large studies provide no support for current recommendations to use fish oil supplements to prevent heart attacks and strokes.”
The researchers found no association of use of the supplements with risk of death from heart disease, non-fatal heart attacks or other major cardiovascular events. Moreover, there was no differential effect of use of fish oil supplements on major cardiovascular events in people with or without prior coronary heart disease, diabetes, high lipid levels or use of statins.
Professor Jane Armitage said “Observational studies suggest that fish oils may protect against heart disease, but the overall results from combining all the large randomised trials (which are much more reliable) suggest that fish oils are safe but do not provide any benefit.”