[Dynamics of the composition of lipids in human milk during lactation].

The authors have studied the total lipids, triglycerides and cholesterol in the milk of 30 mothers over a lactation period of 4 days to 10 months. The total lipids showed diurnal oscillations with a minimal level in the morning and maximal level (P less than 0.001) at 1 p.m. and a slight decrease in the evening, without reaching the levels found in the morning. The lipid concentration in the milk decreases after 4 months of lactation. The oscillations of the lipids take place on the expense of the triglyceride content (r = 0.99). Cholesterol represented on the average 1.54% of the lipid content, showed a maximum level at a month and decreased after 6 months of lactation. The dynamics of lipid composition of the human milk suggests a physiologic significance in the development of the infant.