Association of serum n−6 and n−3 polyunsaturated fatty acids with lipids in 3 populations of middle-aged men123

The association of serum polyunsaturated fatty acids (PUFAs) with lipids in different populations is not known.Our aim was to examine the association of serum n-6 (omega-6) or n-3 (omega-3) PUFAs with triglycerides or HDL-cholesterol concentrations in 261 white, 285 Japanese, and 212 Japanese American men aged 40-49 y.We used a population-based cross-sectional study. Of the original sample (n = 926), those taking lipid-lowering medications or who had diabetes (n = 168) were excluded. Serum fatty acids were analyzed by capillary gas-liquid chromatography. Multiple regression models as a function of tertile groups of each PUFA were used.Serum n-6 PUFAs were significantly inversely associated with triglycerides across populations after adjustment for age, body mass index, pack-years of smoking, and ethanol consumption [beta = -0.39 (P0.001), -0.38 (P0.001), and -0.33 (P0.001) in whites, Japanese, and Japanese Americans, respectively]. Marine n-3 PUFAs were significantly inversely associated with triglycerides across populations [beta = -0.15 (P0.001), -0.22 (P0.001), and -0.13 (P0.001) in whites, Japanese, and Japanese Americans, respectively]. n-6 PUFAs were significantly positively associated with HDL cholesterol in whites (beta = 4.49, P0.001) and Japanese (beta = 3.73, P0.01). Marine n-3 PUFAs were significantly positively associated with HDL cholesterol in Japanese (beta = 2.15, P0.05), and eicosapentaenoic acid was significantly positively associated with HDL cholesterol in whites (beta = 2.68, P0.01).Serum n-6 and n-3 PUFAs are inversely associated with triglycerides across populations.