Assessment of phytochemical content in human milk during different stages of lactation

Objective: The present study reports the presence of several carotenoids and flavonoids in human milk samples. Methods: Samples were collected from 17 women who delivered healthy term babies (>= 37 wk of gestation) at 1-, 4-, and 13-wk postpartum intervals. Results: Epicatechin (63.7-828.5 nmol/L), epicatechin gallate (55.7-645.6 nmol/L), epigallocatechin gallate (215.1-2364.7 nmol/L), naringenin (64.1-722.0 nmol/L), kaempferol (7.8-71.4 nmol/L), hesperetin (74.8-1603.1 nmol/L), and quercetin (32.5-108.6 nmol/L) were present in human milk samples with high inter-intraindividual variability. With the exception of kaempferol, the mean flavonoid content in human milk was not statistically different among lactation stages. In contrast, carotenoids alpha-carotene (59.0-23.2 nmol/L), beta-carotene (164.3-88.0 nmol/L), alpha-cryptoxanthin (30.6-13.5 nmol/L), beta-cryptoxanthin (57.4-24.8 nmol/L), zeaxanthin (46.3-21.4 nmol/L), lutein (121.2-56.4 nmol/L), and lycopene (119.9-49.5 nmol/L) significantly decreased from weeks 1 to 13 of lactation. Conclusion: The observed differences in the relative concentrations of the two phytochemical classes in human milk may be a result of several factors, including dietary exposure, stability in the milk matrix, efficiency of absorption/metabolism, and transfer from plasma to human milk. These data support the notion that flavonoids, as with carotenoids, are dietary phytochemicals present in human milk and potentially available to breast-fed infants. (C) 2013 Elsevier Inc. All rights reserved.