Differences in plasma and nipple aspirate carotenoid by lactation status

Background: Dietary antioxidants, such as provitamin A have a protective ef fect against breast cancer. The transport of carotenoid from the blood into the breast microenvironment may be enhanced by lactation. Objective: To examine the association between plasma and nipple aspirate ca rotenoid levels by lactation and post-wean status. Methods: The sample consisted of 43 women, ages 18-45, who were at least 12 months postpartum. Women Who had breastfed their last infant were at least 3 months post-wean. Women collected breast fluid every other day for 17 da ys and had a venipuncture for total nipple aspirate and plasma carotenoid, and completed a written health assessment, Results:The association between plasma and nipple aspirate carotenoid level s was significant for breastfeeding women (r = .39, p = .03), but not for n on-breastfeeding women (r = .31, p = .27). However, while the association b etween plasma and nipple aspirate carotenoid levels was significant far wom en at or less than 3 months post-wean (r = .65, p = .01), the effect for wo men after 9 months post-wean (r = .21, p = .45) was not significant. Conclusion: Lactation may be protective by enhancing the delivery of chemop reventive substances available in the blood to the cell level of the breast , even after breast involution has occurred post lactation.