Consumption of polyunsaturated fatty acids, fish, and nuts and risk

n3 (omega-3) Polyunsaturated fatty acids (PUFAs), fish, and nuts can regulate inflammatory processes and responses. We investigated whether dietary intakes of PUFAs [n-3,n6 (omega-6), and alpha-linolenic acid], fish, and nuts were associated with 15-y mortality attributed to non-cardiovascular, non-cancer inflammatory diseases. The analyses involved 2514 participants aged 49 y at baseline. Dietary data were collected by using a semi-quantitative food-frequency questionnaire, and PUFA, fish, and nut intakes were calculated. Inflammatory disease mortality was confirmed from the Australian National Death Index. Over 15 y, 214 subjects died of inflammatory diseases. Women in the highest tertiles of total n-3 PUFA intake, compared with those in the lowest tertile of intake at baseline, had a 44% reduced risk of inflammatory disease mortality (P for trend = 0.03). This association was not observed in men. In both men and women, each 1-SD increase in energy-adjusted intake of alpha-linolenic acid was inversely associated with inflammatory mortality (hazard ratio: 0.83; 95% CI: 0.71, 0.98). Subjects in the second and third tertiles of nut consumption had a 51% and 32% reduced risk of inflammatory disease mortality, respectively, compared with those in the first tertile. Dietary intakes of long-chain n-3 and n-6 PUFAs and fish were not associated with inflammatory disease mortality. We report on a novel link between dietary intake of total n-3 PUFA and risk of inflammatory disease mortality in older women. Furthermore, our data indicate a protective role of nuts, but not fish, against inflammatory disease mortality. [Authors abstract]
This study provides epidemiologic evidence on the association between inflammatory disease mortality and dietary intake of PUFAs, fish, and nuts. In this older cohort, women in the higher tertiles compared with those in the lower tertiles of total n-3 intake had a 43% reduced risk of dying from non-cardiovascular, non-cancer inflammatory diseases. This protective effect was not observed in men. In addition, each 1-SD increase in energy-adjusted intake of ALA was associated with a 17% decreased risk of dying from inflammatory diseases. In contrast, neither long-chain n-3 PUFAs nor fish intake reduced the risk of chronic inflammation-related mortality. Evidence suggests that older women are more sensitive to the ability of n-3 PUFAs to reduce the production of inflammatory cytokines. ALA has been shown to significantly decrease cell adhesion molecules, including E-selectin. Because ALA is the most frequently consumed n-3 fatty acid in Western diets, this data suggest that dietary intake of ALA, specifically at higher intakes than currently consumed, could be a simple-to-implement anti-inflammatory intervention. [Editors comments]