Associations between dietary long‐chain n3 and n6 polyunsaturated fatty acids, red blood cell fatty acids and C‐reactive protein among elderly men and women in Utah

Objective To examine associations between dietary intakes of long‐chain n3 (LCn3) and n6 polyunsaturated fatty acids (PUFAs), red blood cell (RBC) fatty acids (FAs) including eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids, and C‐reactive protein (CRP), a marker of inflammation, among elderly men and women. Methods Dietary intakes of 691 male and 959 female participants of the Cache County Study on Memory and Aging who were ≥73 years of age were assessed using a food frequency questionnaire. Associations were assessed using general linear models. Increasing quintiles of dietary LCn3 PUFA but not n6 PUFAs were positively associated with RBC EPA (P <0.001, 0.966, respectively) and DHA (P <0.001, 0.304, respectively). However, neither dietary n6 or LCn3 PUFAs nor RBC FAs alone were associated with CRP. Of interest, interactions between dietary n6 and LCn3 PUFA intakes were significant for RBC EPA, DHA and CRP (P = 0.003, 0.001, 0.05, respectively). Participants with lower (< median) dietary n6 and higher (> median) LCn3 had the highest mean RBC EPA and DHA levels. In addition, participants with higher dietary n6 and lower dietary LCn3 had the highest mean CRP levels. Conclusion The influence of dietary FAs on RBC LCn3 FA composition and CRP may depend on the interaction between absolute intakes of both LCn3 and n6 PUFAs. Funded by the General Mills Bell Institute and NIH‐NIA RO1‐AG21136/AG11380.