Erythrocyte long-chain omega-3 fatty acid levels are inversely associated with mortality and with incident cardiovascular disease: The Framingham Heart Study.

•The RBC Omega-3 Index was measured in 2500 people in the Framingham Offspring.•Risk for death from any cause between ages 66 and 73 years was compared to the Index.•Total mortality was 35% lower in those in the highest quintile compared to those in lowest quintile.•The Omega-3 Index can serve as a marker of overall health in older Americans.