[Pattern of total antioxidant capacity in human milk during the course of lactation]

ABSTRACT

In addition to numerous nutrients, human milk contains several antioxidants as bioactive components protecting newborns from a hyperoxic challenge due to transition to an environment much richer in oxygen. The aim of this study was to evaluate the changes of total antioxidant capacity of human milk during the first six months of lactation. 535 milk samples were collected from 145 healthy women with full term newborns. Analyses included colostrum [at 2 +/- 1 day postpartum], transitional milk [at 7 +/- 3 days postpartum] and mature milk [at 30 +/- 5, 90 +/- 7 and 180 +/- 10 days postpartum] and also maternal plasma at 90 +/- 7 days. The total antioxidant capacity of samples was measured by Ferric Reducing/Antioxidant Power [FRAP] assay. Colostrum showed a significant higher antioxidant capacity than the transitional and mature milks [589.8 +/- 278.1 vs. 508.5 +/- 284.1, 453.5 +/- 210.8, 479.3 +/- 254.3 and 402.6 +/- 168.0 micro mol/l respectively]. Also a significant decrease in antioxidant capacity was observed in the mature milks [p<0.05]. The relationship between the antioxidant content of breast milk and maternal plasma was significant too [p<0.05, r=0.267]. These data suggest that colostrum, with high antioxidant capacity, during the first days of life is vital; moreover, reduction in total antioxidant capacity during the course of lactation is notable and requires sophisticated measures: