There is no evidence that taking omega-3 fatty acid supplements is useful for preventing cardiovascular disease, conclude primary care researchers.
Previous studies have shown an association between omega-3 supplementation and reduced cardiovascular mortality and morbidity after a heart attack and in patients with heart failure. This Italian placebo-controlled study looked at the introduction of omega-3 fatty acid supplementation by GPs in 12,505 men and women with multiple cardiovascular risk factors or atherosclerotic vascular disease, but no history of myocardial infarction. The primary end point was the cumulative rate of death, nonfatal myocardial infarction and nonfatal stroke. One year into the study the event rate was ‘lower than anticipated’ and the primary end point was revised as time to death from cardiovascular causes or hospital admission for cardiovascular causes.
After five years, the primary end point occurred in 1,478 patients (11.8%), of whom 733 had received n-3 fatty acid supplements and 745 had received placebo (11.7% and 11.9% of the total sub-groups respectively), a non-significant difference. Overall, hospital admissions for cardiovascular causes were mainly in patients >65 years, and only 7.7% of patients admitted to hospital for cardiovascular causes died from them during the study.
What this means for GPs
The researchers noted that their results ‘provide no evidence of the usefulness of n-3 fatty acids for preventing cardiovascular death or disease’ in the patients analysed, despite efforts in the study to ‘to optimize medical therapies and control cardiovascular risk factors’.