Estrogen therapy linked to lower Alzheimer's risk, Stanford study finds

Key Points:

• A large Stanford study published in Neurology found that women who used estrogen-only menopausal hormone therapy (MHT) had a 35% lower chance of Alzheimer’s pathology and 39% lower odds of dementia compared to non-users.
• The study analyzed post-mortem brain data from over 21,000 participants, focusing on amyloid plaques and neurofibrillary tangles, hallmarks of Alzheimer’s disease, and found estrogen-only users had fewer such changes.
• Estrogen-only MHT users, mostly women who had hysterectomies, also performed better on memory tests and maintained greater independence, supported by biomarkers in blood and cerebrospinal fluid.
• Researchers caution that the observational study shows association but not causation, and emphasize the need for prospective clinical trials to confirm if menopausal hormone therapy has a protective cognitive effect.
• These findings challenge previous studies linking MHT to increased dementia risk and highlight estrogen’s neuroprotective roles, including reducing neuroinflammation and supporting brain plasticity.