A study following 2240 adults, mean age 65, over an eleven year period, indicates that consumption of omega-3 fatty acids may prolong life by up to five years. For comparison, being a smoker at the age of 65 is likely to subtract 4.7 years of life compared to non-smokers. The research originally set out to establish lifestyle factors which could indicate whether an individual could be at increased risk of cardiovascular disease eg unhealthy diet, lack of exercise, smoking etc. A 2018 study on 2500 people suggested that good omega-3 intake was associated with reduced mortality from all causes.
(Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort. The American Journal of Clinical Nutrition, 16 June 2021.)