Fat and protein composition of mature milk in adolescents.

The levels of certain components, notably total protein, total fat, energy, and fatty acids, of mature milk from 48 adolescent and 44 adult mothers was studied. These two groups were subdivided into high and low socioeconomic level (SEL). All mothers were primiparous, eutrophic, and with term pregnancy; and their newborns weighted over 2500 g at birth. The age factor appeared to have significant influence on the concentration of total protein, with higher levels in the group of adolescent mothers possibly as a compensatory mechanism to maintain the caloric value of the milk. The fatty acid content was altered significantly by the SEL probably due to the direct effect of maternal diet. The milk in adolescent mothers of low SEL demonstrated higher concentration of lauric and myristic acids, while the milk in low SEL adults contained higher proportions of linoleic and linolenic acids. The milk in adult mothers of high SEL demonstrated higher concentrations of palmitic, palmitoleic, and oleic acids. The different feeding habits of two socioeconomic groups may explain these results. The regular intake of soya oil, corn oil, and margarine by the urban population in general resulted in higher levels of linoleic acid in the milk of all groups studied.