Published in the Journal of Clinical Lipidology, researchers found that the risk of death was reduced by about a third in people who had the highest omega-3 index, compared with those who had lower omega-3 levels. Using data from 2,500 participants from the Offspring cohort of the Framingham Heart Study, the participants of the study had an average age of 66 years and were all free of cardiovascular disease at the beginning of a study. The team conducted follow-ups on the participants over an average period of seven years, in which incidence of death, stroke, cardiovascular disease, and coronary heart disease were recorded. The data that was gathered was compared with that of the omega-3 index and total cholesterol. A resultant omega-3 index value of more than 8% is categorized as optimal or low-risk, while values 4-8% are classified as intermediate-risk, and lower than 4% as high-risk.
Results revealed that omega-3 index is closely associated with the overall risk of death and cardiovascular disease. Those in the highest compared to those in the lowest omega-3 index quintiles had a 34% lower risk for death from any cause and 39% lower risk for incident CVD. Moreover, it had a significant association with four of the five major outcomes – the incidence of coronary heart disease, cardiovascular disease, and total and cardiovascular disease mortality. Additionally, the omega-3 index was a better indicator than cholesterol for risk for death and some measures of cardiovascular disease. The researchers found that serum cholesterol levels were not significantly associated with any of the outcomes, unlike the omega-3 index.