Commentary

Observational studies have reported an inverse association between fish consumption and risk for CAD. Since the initial reports over 20 years ago, evidence has accumulated that fish oil fatty acids decrease the risk for CAD. In the meta-analysis by Bucher et al, the results from secondary CAD prevention trials analysing intake of fish, omega-3 fish oil supplements, and α-linolenic acid (a plant-based omega-3 fatty acid) were pooled to estimate the effect of these fatty acids on recurrent CAD events and total mortality. Consumption of omega-3 fatty acids in these trials conferred approximately a 20% to 30% reduction in CAD events and total mortality. Only 1 study examined the effect of α-linolenic acid, which, along with such other dietary changes as increased consumption of fruit, vegetables, and fibre, resulted in a 72% reduction in the risk for non-fatal MI and death from CAD over 46 months of follow up.¹ On average, the magnitude of the reported benefit from the omega-3 fatty acids is similar to that seen from statins. Fish oil fatty acids have beneficial effects on platelet aggregation, lipids, endothelial function, inflammation, and the risk for sudden death.

Current recommendations for non-pregnant healthy adults are to eat ≥ 2 servings of fish per week,² which may lower the relative risk for CAD by ≥ 50%. For patients with known CAD, the daily consumption of fatty fish (eg, herring, mackerel, and salmon) or approximately 1 g of a fish oil supplement may be recommended to decrease the risk for recurrent events.²