San Diego—Estrogen is a hormone adept at multitasking. Not only does this ubiquitous molecule influence reproduction, it plays a role in bone and mineral metabolism, cardiac and vascular function, and various aspects of cognition, such as memory. But discovering the ways in which estrogen wields its influence in various organ systems such as the brain has been challenging.
Over the years basic research has suggested mechanisms by which estrogen contributes to brain functioning, but clinical studies have produced conflicting results. For example, a randomized, double-blind, placebo-controlled study showed that estrogen replacement therapy given for 1 year did not slow cognitive decline in women with mild to moderate Alzheimer disease (AD) who have had hysterectomies (JAMA. 2000;283:1007-1015). And a meta-analysis of studies evaluating hormone replacement therapy (HRT) for prevention of cognitive decline showed that HRT may have beneficial cognitive effects in women with menopausal symptoms but not in asymptomatic women (JAMA. 2001;285:1489-1499).
Friedrich MJ. Teasing Out Effects of Estrogen on the Brain. JAMA. 2002;287(1):29-30. doi:10.1001/jama.287.1.29