Maternal breastfeeding history and Alzheimer’s risk

Background: The effect of early and midlife factors on later-life cognitive function has attracted scientific and public interest in recent years, especially in terms of hormonal risk factors for dementia. Given the substantial evidence for roles of ovarian hormones, insulin sensitivity, and inflammation in Alzheimer’s Disease (AD) etiology, here it is hypothesized that breastfeeding history may affect women’s risk of AD.Methods: Reproductive history information was collected and Alzheimer’s diagnostic interviews were performed for a cohort of elderly British women (N = 133).Results: Using Cox regression models, we find that history of longer breastfeeding duration corresponded to reduced risk of AD onset in women without family history of AD. This effect was absent in women with family history of AD. Conclusions: Breastfeeding practices are an important modifier of cumulative endogenous hormone exposure for mothers. Progesterone deprivation and/or glucose tolerance benefits of breastfeeding may be responsible for the observed reduction in AD risk. Future studies concerning hormone effects on AD risk should consider how reproductive history leads to variation in endogenous hormone exposure, and the role thismay play in the relationship between hormones and AD.Keywords: Alzheimer’s Disease, risk factors, breastfeeding, lactation, reproductive history, hormones, estrogen, prolactin, inflammation