A large study has found that women who used estrogen-only hormone therapy later in life were less likely to show signs of dementia and Alzheimer’s disease, according to ScienceDaily.
The research, published August 12, 2026, in Neurology, analyzed medical data from more than 21,000 women. Some participants had brain scans or biomarker testing during life, while others underwent autopsies after death so researchers could look for evidence of Alzheimer’s disease.
Among the women studied, those who used hormone therapy were less likely to have the brain changes associated with Alzheimer’s. After accounting for factors such as age, education, genetics, race and hypertension, hormone therapy use was linked to 35% lower odds of showing those signs at autopsy.
The study also found that hormone therapy use was associated with 39% lower odds of a clinical dementia diagnosis. Women who used the therapy were also less likely to have memory problems or declines in everyday functioning.
Researchers stressed that the findings show an association and do not prove hormone therapy can prevent dementia. Study author Jennifer Bruno of Stanford Medicine said the results may not apply to current treatment practices because the women in the study used hormone therapy decades ago and often started around age 70.
