Fatty acid compositions of preterm and term colostrum, transitional and mature milks in a sub-Saharan population with high fish intakes.

Background: There are no data on the fatty acid (FA) compositions of preterm and term milks for sub-Saharan African populations with advancing lactation. However, it is generally acknowledged that our ancestors evolved in sub-Saharan East-Africa, where they inhabited the land-water ecosystems.
Methods: We compared the FA-compositions of preterm (28-36 weeks) and term (37-42) colostrum (2-5 day), transitional (6-15) and mature (16-56) milks in rural African women with stable dietary habits and lifelong high freshwater fish intakes.
Results: From colostrum to mature milk: the median docosahexaenoic acid (DHA) content decreased from 1.11 to 0.75; and arachidonic acid (AA) from 0.93 to 0.69 g% in preterm milk. In term milk, DHA decreased from 0.81 to 0.53 and AA from 1.08 to 0.55 g%. Medium-chain saturated-FA (MCSAFA) increased from 16.9 to 33.7, and 7.92-29.0 g%, while mono-unsaturated FA (MUFA) decreased from 32.5 to 22.6, and 40.0-26.5 g%, in preterm and term milk, respectively. Consistent with the literature, preterm colostrum contained higher DHA and MCSAFA, and lower MUFA compared to term colostrum. These differences vanished rapidly with advancing lactation. MUFA and MCSAFA were inversely related.
Conclusions: The presently found DHA in preterm colostrum and mature milks and AA in premature mature milk proved the highest reported in the literature so far, as derived from analysis with capillary GC-columns. We confirmed the much higher MCSAFA and lower MUFA contents in milk of rural African, compared to Westernized women. The milk FA composition of this traditional population might show us the FA composition on which our species evolved and consequently to which our genome has become adapted to optimally support (infant) health.
(Copyright © 2012 Elsevier Ltd. All rights reserved.)