Dietary fat in relation to erythrocyte fatty acid composition in men.

Erythrocyte membrane fatty acid (EMFA) composition is used in the validation of food frequency questionnaires (FFQ) and the evaluation of dietary fat quality. In this cross-sectional study we aimed to investigate associations of diet with EMFA. Altogether, 1,033 randomly selected Finnish men, aged from 47 to 75 years filled in a FFQ and their EMFA composition was analyzed. Marine polyunsaturated fatty acid (PUFA) intake correlated positively with erythrocyte eicosapentaenoic and docosahexaenoic acids (r(s) = 0.415 and r(s) = 0.340, respectively, P < 0.001) and inversely with all n-6 PUFA analyzed (P < 0.001). PUFA intake from spreads and cooking fats correlated positively with alpha-linolenic (ALA), linoleic (LNA) and nervonic acids (r(s) = 0.229, r(s) = 0.160 and r(s) = 0.143, respectively, P < 0.001). Milk fat intake was associated with myristic and behenic acids (r(s) = 0.186 and r(s) = 0.132, respectively P < 0.001). Butter users had lower ALA and LNA proportions (mol%) than non-users (0.16 ± 0.04 vs. 0.19 ± 0.05, P < 0.001 and 7.77 ± 1.02 vs. 8.12 ± 1.11, P = 0.001). Higher PUFA intake from meat was related to decreased long-chain n-3 (P < 0.001) and increased n-6 PUFA (P < 0.001) proportions. In conclusion, EMFA composition reflects particularly well the intakes of n-3 PUFA, whereas other associations remained lower. Yet, all main sources of dietary fat were related with EMFA. The dietary effect on the nervonic acid proportion was confirmed.