The effects of dietary fatty acids and cholesterol on the milk lipids of lactating women and the plasma cholesterol of breast-fed infants

Abstract

The plasma cholesterol concentration and the composition of the plasma fatty acids was altered by dietary means in 10 lactating women. The effects of these changes in the plasma on the lipid constituents of mature human milk were studied over periods of several weeks. In eight infants who were being breast-fed, the changes in the plasma cholesterol concentration were correlated with the changes that were induced in the milk lipids. Significant alteration in the women's plasma cholesterol levels did not change the cholesterol concentration in milk. The cholesterol content of milk was closely correlated with the concentrations of the other milk lipids, supporting a functional role for the cholesterol in the secretion of milk fat. In the maternal milk consumed by the eight infants the linoleate content rose from 9.4% to 15.5% of total fatty acids as a result of a moderate increase in dietary polyunsaturated fat. This led to a fall in the infants' plasma cholesterol levels, from an average of 185 to 157 mg/100 ml.