Guidelines supporting an increased intake of omega-3 fatty acids to prevent cardiovascular disease in those at high-risk are not supported by trials, say Greek researchers.
Their analysis pooled 20 randomised controlled trials looking at 68,680 patients aged 49 to 70 years taking omega-3 polyunsaturated fatty acids for primary or secondary prevention of cardiovascular disease.
Patients were randomised to either a diet high in omega-3 polyunsaturated fatty acids or supplements, and the effects were compared with controls on an alternative diet or placebo, for at least one year.
They found that the risk of all-cause mortality was reduced by just 4% compared with controls, and this difference was not statistically significant. Risk of cardiac death was reduced by 9%, sudden death by 13% and myocardial infarction by 11% compared with controls. None of these reductions were statistically significant.
Omega-3 supplements increased the risk of stroke by 5% compared with controls, but this increase was statistically non-significant.
The researchers concluded: ‘Our findings do not justify the use of omega-3 as a structured intervention in everyday clinical practice or guidelines supporting dietary omega-3 PUFA administration.’