Researchers have found that omega-3 levels in blood erythrocytes are very good mortality risk predictors. The study used data from a long-term study group, the Framingham Offspring Cohort, which has been monitoring residents of this Massachusetts town, in the United States, since 1971 and concludes that "Having higher levels of these acids in the blood, as a result of regularly including oily fish in the diet, increases life expectancy by almost five years",
