EFFECTS OF VARYING MATERNAL DIETARY FATTY-ACIDS IN LACTATING WOMEN AND THEIR INFANTS

This report evaluates the effects of variation of maternal dietary polyunsaturated and saturated fats on maternal plasma and milk fatty acids, and subsequently on infant plasma fatty acids. The 14 mothers took an ad libitum diet for 30 days after delivery and then were randomized to one of two diets: one (polyunsaturate-rich) with a P/S of 1.8 and 190 mg cholesterol per day; the second (saturate-rich) with a P/S of 0.12 and 520 mg cholesterol per day. After 4 weeks on either diet, the mothers then crossed over to the other for a 2nd 4-week period. Breast milk constituted the infants' sole intake during the two periods. On the polyunsaturate-rich diet, milk content of linoleic acid (18:2) was more than doubled, while the levels of palmitoleic (16:1), stearic (18:0), palmitic (16:0), and myristic (14:0) fatty acids were all reduced. The fatty acid pattern in milk for the ad libitum dietary period was qualitatively very similar to that for the saturate-rich period. Comparing the polyunsaturate-rich to the saturate-rich maternal diet periods, infant plasma linoleate rose and oleate fell on the polyunsaturate-rich diet. There were very close and significant relationships between maternal milk and infant plasma 16:0, 16:1, 18:2, and 20:3 fatty acids. The closest relationship was observed for 18:2, r = 0.83, P = 0.0001. Ingestion of the polyunsaturate-rich, saturate-poor breast milk did not affect the plasma cholesterol levels of the infants. By partaking of a polyunsaturate-rich diet, the lactating mother can provide polyunsaturate-rich breast milk, and sharply increase the polyunsatured fatty acid levels in her infant. The physiological significance of maternal-infant fatty acid relationships on varied diets is difficult to define.