Effect of dietary fat on fatty acid composition in human milk

The fatty acid composition of 25 human milk samples was determined by using capillary gas-liquid chromatography. The breast milks were obtained from 10 vegetarians and 15 non-vegetarians (mixed diet). The intake of linoleic acid (18:2n-6) was higher in vegetarian group (p<0.01) than in omnivores. The intake of <alpha>-linolenic acid (18:3n-3) was similar in both nutritional groups and did not reach the recommended dietary allowance (RDA). The breast milk of vegetarian women had lower percentages of palmitic acid (p<0.01), oleic acid (p<0.05), cis monounsaturated fatty acids (p<0.01) and n-3 long-chain polyunsaturated fatty acids (p<0.05), while n-6 polyunsaturated fatty acids, linoleic acid (p<0.01), polyunsaturated fatty acids/saturated fatty acids ratio were significantly elevated. The proportion of total trans fatty acids was insignificantly higher in the milk of vegetarians than in that of omnivores. The estimated daily intake of trans 18:1 in vegetarians and omnivores was 7.24 g/person and 4.98 g/person, respectively. The percentages of trans 18:1, 18:2n-6, 18:3n-3 in serum showed a significant positive relation (p<0.0001) to the percentages of same fatty acid in the breast milk of lactating vegetarians and omnivores.