Dietary α-linolenic acid intake, different food sources and risk of all-cause mortality: a prospective cohort study.

Evidence about the association between dietary α-linolenic acid (ALA) intake and all-cause mortality risk remains insufficient, and less is known about the contribution of its major food sources. This study aimed to investigate the associations of dietary ALA intake and its different food sources with all-cause mortality risk among adults. A total of 12,217 participants from the China Health and Nutrition Survey (CHNS) 1997-2011 and 40,217 participants from the U.S. National Health and Nutrition Examination Survey (NHANES) 1999-2018 were included. After multivariable adjustment, the highest quartile of dietary ALA intake showed a 19% lower risk of all-cause mortality compared to the lowest quartile (pooled hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.72-0.91), including a 23% reduction in CHNS and 17% reduction in NHANES. Each 1g/d increment in dietary ALA intake was associated with a 4% lower risk of all-cause mortality (pooled HR: 0.96; 95% CI: 0.93-0.99), in a linear dose-response manner (P-nonlinear = 0.423). For major dietary ALA sources, the highest consumption of plant oils (pooled HR: 0.86; 95% CI: 0.76-0.97), beans and vegetables (0.83; 0.76-0.90), nuts (0.78; 0.68-0.89), poultry and fish (0.89; 0.79-0.99) was associated with a lower risk of all-cause mortality compared with the lowest consumption. In conclusion, higher intakes of dietary ALA and its major plant food sources were associated with a lower risk of all-cause mortality. Consuming adequate amounts of ALA from plant-based foods could play a role in reducing the risk of all-cause mortality.