Women with hysterectomies who received estrogen-only hormone therapy at menopause had 35% lower odds of showing Alzheimer's disease hallmarks — including amyloid plaques — in their brains at autopsy compared with women who did not receive estrogen, according to a study published in the journal Neurology.
Study links estrogen-only therapy to lower Alzheimer's brain markers in women with hysterectomies
Women with hysterectomies who received estrogen-only hormone therapy at menopause had 35% lower odds of showing Alzheimer's disease hallmarks — including amyloid plaques — in their brains at autopsy compared with women who did not receive estrogen, according to a study published in the journal Neurology.
Researchers analyzed health records and post-mortem brain autopsy findings from more than 5,000 older women who had hysterectomies. By using autopsy data rather than clinical ratings or cognitive assessments, the authors say the study adds an objective measure of Alzheimer's disease pathology that earlier research lacked.
Previous studies of hormone therapy and Alzheimer's risk have produced mixed results, with some indicating reduced risk, others showing no benefit, and still others suggesting increased risk. The Women's Health Initiative hormone-therapy trial, whose initial results were released in 2002, found that treatment — in that case a combination of estrogen and progesterone — increased women's risk of both breast cancer and dementia, while showing no benefit for reducing Alzheimer's risk.
The new study focused on estrogen alone, not the estrogen-progesterone combination more commonly prescribed for menopausal symptoms. Progesterone is typically added to protect the uterus, but women who have had a hysterectomy can be prescribed estrogen without it, making that population useful for isolating estrogen's effects.
The study did not specify when the women began estrogen therapy, which formulation they used, or how long they remained on it. The authors say future research should be designed to capture those variables and could include trials tracking women from perimenopause through menopause, monitoring blood and spinal fluid biomarkers and brain imaging alongside clinical outcomes.
- The source does not state the specific formulations of estrogen used by women in the study.
- The source does not state when the women in the study began estrogen therapy relative to the onset of menopause.
- The source does not state how long the women in the study remained on estrogen therapy.
- The source does not provide the name of the lead author or the full list of institutions involved beyond Stanford University.
- The source does not state the funding sources for the study.
- The source does not state whether the study was peer-reviewed beyond noting it was published in Neurology.