ScienceDaily.com
Women who used estrogen-only hormone therapy later in life were less likely to develop dementia and showed fewer signs of Alzheimer’s disease in their brains, according to a large study of more than 21,000 participants. Hormone therapy use was linked to 39% lower odds of a dementia diagnosis and 35% lower odds of Alzheimer’s-related brain changes at autopsy, including amyloid plaques and tau tangles. Biomarker tests also suggested less amyloid buildup among hormone therapy users.

A large study has found that women who used hormone therapy later in life had a lower risk of developing dementia. The findings were published August 12, 2026, in Neurology, the medical journal of the American Academy of Neurology.
Researchers emphasized that the results show an association and do not demonstrate that hormone therapy can prevent dementia.
“While these findings help us better understand the relationship between hormone therapy use and various markers of dementia, more research needs to be done before we can make recommendations to women about their use of these therapies in relation to their brain health,” said study author Jennifer Bruno, PhD, of Stanford Medicine in Stanford, California. “This study looked back at women who were using hormone therapy decades ago with the timing and type of use differing from what is current practice for most women today, so the results are informative, but they may not apply to today’s standards.”