Marine n−3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer

This large-scale randomized controlled trial, the VITAL study, examined whether marine-derived omega-3 fatty acid supplementation (1g/day) reduces the risk of cardiovascular disease and cancer in a general population. Over 25,000 participants (men aged ≥50, women aged ≥55) were randomly assigned to either omega-3 supplements or a placebo, with a median follow-up of 5.3 years.

The results showed no significant reduction in major cardiovascular events or invasive cancer rates in the omega-3 group compared to the placebo. However, a lower risk of myocardial infarction (heart attack) was observed, particularly in individuals with lower fish consumption. No excess risks of adverse effects, including bleeding, were detected.

Statistical significance: The study had sufficient power to detect meaningful effects, but findings were mostly null. The minor reduction in myocardial infarction warrants further investigation but does not support widespread omega-3 supplementation for cardiovascular or cancer prevention.

Limitations: The study duration may not have been long enough to capture long-term effects on cancer. The single dose used (1g/day) limits the ability to assess dose-response relationships.

Although omega-3 supplementation did not significantly reduce cardiovascular or cancer risk, individuals with low dietary fish intake may consider increasing their consumption of fatty fish (e.g., salmon, mackerel, sardines) to support heart health. A diet rich in whole foods, including fish, vegetables, and whole grains, remains a well-supported approach to cardiovascular disease prevention.