LIPOPROTEIN COMPOSITION AND SERUM-CHOLESTEROL ESTER FATTY-ACIDS IN NONWESTERNIZED MELANESIANS

In this study, the relationships between dietary fat [as measured by s erum cholesterol ester fatty acids (CE-FA)], age, smoking, body mass i ndex, and serum lipids were analyzed in 151 subsistence horticulturali sts, aged 20-86 yr, from Kitava, Trobriand Islands, Papua New Guinea. Their diet consists of tubers, fruit, coconut, fish, and vegetables wi th a negligible influence of western food and alcohol. Total fat intak e is low [21% of energy (en%)], while saturated fat intake from coconu ts is high (17 en%, mainly lauric and myristic acid). In multivariate analysis, 11-43% of the variation of the serum lipoprotein composition was explained by CE-FA, age, and smoking habits. The proportion of CE 20:5n-3 explained much of the variation of triglycerides (TG, negative relation) and high density lipoprotein-cholesterol (HDL-C, positive) in both sexes and serum apolipoprotein A1 (ApoA1, positive) in the mal es. CE16:0 was positively related to TG and negatively related to HDL- C and ApoA1 in both sexes, and in males it related negatively to total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C). In males, negative relationships were present between CE18:2n-6 and TC an d between CE14:0 and serum lipoprotein(a). Smoking was independently a ssociated with lower ApoA1 in both sexes and with lower HDL-C and high er TG, TC, LDL-C, and apolipoprotein B in males. In conclusion, marine n-3 fatty acids and linoleic acid showed the same potentially benefic ial relationships with lipoproteins and apolipoproteins as in western populations. The relations of palmitic acid to serum lipids may be exp lained in terms of endogenous fat synthesis at a low-fat intake, rathe r than reflecting its relative intake.