Fatty acid patterns of human milk.

An analysis of the fatty acid content of 110 early morning samples of breast milk from 26 mothers shows a shift in the fatty acid pattern toward higher values for C 18:2 fatty acids than those reported previously. This shift has paralleled an increase in the use of vegetable oils and an increase in the P/S ratio of the American diet. The fatty acid pattern varied from day to day only for C 18:1. There were no significant variations among morning, midday, and evening values for samples provided by eight mothers.