DEPENDENCE OF HUMAN-MILK ESSENTIAL FATTY-ACIDS ON ADIPOSE STORES DURING LACTATION

The relationships between essential fatty acid (EFA) composition of co lostrum, mature milk, and white adipose tissue (WAT) were examined on days 5 and 30 postpartum in 24 healthy French mothers. Fatty acid comp osition was assessed by capillary gas chromatography. In WAT, the prop ortion of individual polyunsaturated fatty acids (PUFAs) did not chang e during lactation and was greater (18:2n-6) or lower (18:3n-3, long-c hain PUFAs) than values found in colostrum or mature milk (P < 0.04). The 18:2n-6 content and the ratio of 18:3n-3 to 18:2n-6 correlated bet ween WAT and colostrum (r = 0.52 and r = 0.57, respectively) or mature milk (r = 0.64 and r = 0.65. respectively). These relationships agree with an expected qualitative effect of WAT fatty acid composition on interindividual variability of milk parent EFA content. The decrease i n the long-chain chain PUFA content observed from colostrum to mature milk and the concomitant occurrence of a precursor-product relationshi p between the linoleate and its long-chain PUFA are consistent with th e mobilization of a preformed long-chain PUFA pool during early lactat ion.