Estrogen Therapy May Help Protect Against Alzheimer’s Disease, Study Says

The women in the new study were prescribed estrogen only, and not the combination of estrogen and progesterone that is more commonly used to treat menopausal symptoms. Progesterone is prescribed to protect the uterus, but women who have had a hysterectomy, like those in the study, can safely be prescribed estrogen. This population provides a good way to study the effects of estrogen itself, since researchers believe it’s the hormone with more wide-ranging effects on the body, including in the brain.

Hadi Hosseini, an associate professor of psychiatry at Stanford and co-author of the study, says the results don’t establish a cause-and-effect link between estrogen and Alzheimer’s disease, but they do provide a reason to further study the role of the hormone in the neurodegenerative disease. “Previous studies,” including the Women’s Health Initiative, “showed that hormone therapy—estrogen plus progesterone—had a negative effect on Alzheimer’s disease risk and memory outcomes,” he says. “These data are bringing awareness to the fact that maybe we need to reconsider some of the previous findings, since we can now look properly at Alzheimer’s disease outcomes, different formulations of hormone therapy, different times of initiating the therapy, and different durations of use.”