Fatty acid composition of the milk lipids of women in Nepal

Abstract

We analyzed the fatty acid composition of the triacylglycerol and phospholipid fractions of human milk samples obtained 2–4 weeks postpartum from 48 women living in rural Nepal. The most noteworthy aspects of the fatty acid composition of the triacylglycerol fraction were the proportions of the two essential fatty acids, linoleic acid (C18:2n-6) and α-linolenic acid (C18:3n-3). The proportion of linoleic acid was very low (7.91%), while that of α-linolenic acid was relatively high (1.93%). Together, the n-3 and n-6 polyunsaturated fatty acids accounted for 12.4% of the total fatty acids in the triacylglycerol fraction, and de novo fatty acids (C10:0–C14:0) accounted for 25.0% of the total, arachidonic acid 0.35%, and docosahexaenoic acid (DHA) 0.21% of the total. In the phospholipid fraction, the two essential fatty acids accounted for 6.38% of the fatty acid total. In the phospholipid fraction, 23.0% of the fatty acids were contributed by de novo fatty acids, 0.57% by arachidonic acid and 0.78% by DHA. The mean body mass index (BMI, kg/m 2) of the women in the Nepal study was in the middle range of other groups we have studied in Nigeria, yet the value of linoleic acid in the triacylglycerol fraction of their milk was lower than the value we found in the milk lipids of the Nigerian women. This leads us to speculate the low proportion of linoleic acid in the milk fat of the Nepalese women is due more to the diet of the population rather than the overall nutritional status of the mothers, as reflected in their BMI values.