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

Alzheimer's disease is more common in women than men, likely due to the decline in estrogen experienced during menopause. A new study published in Neurology suggests that estrogen-only hormone therapy may help protect against Alzheimer's. Researchers examined the brain autopsies of over 5,000 post-menopausal women who had undergone hysterectomies and found that those who received estrogen-only therapy had 35% lower odds of having Alzheimer's hallmarks such as amyloid plaques in their brains compared to those who did not receive the therapy.

Jennifer Bruno, a co-author from Stanford University, notes that previous studies on hormone therapy and Alzheimer's have yielded mixed results, with some indicating a reduced risk and others finding no benefit or even an increased risk. The Women's Health Initiative, a landmark hormone therapy trial, raised concerns about its safety due to increased risks of breast cancer and dementia, but the study's participants were post-menopausal and used a different type of hormone replacement therapy, limiting the generalizability of the results.

Since those in the new study were prescribed estrogen only, it provides a more precise way to study the effects of estrogen itself on the brain. The study's findings do not establish a direct cause-and-effect link between estrogen and Alzheimer's but suggest the need for further research on the hormone's role in the neurodegenerative disease.

Future studies should consider factors such as when women began using estrogen, the specific formulation and duration of therapy to better understand its potential role in preventing Alzheimer's.