Women who used menopausal hormone therapy carried 59% lower odds of a heavy burden of cerebral small vessel disease on MRI scans at ages 70 and 75, according to a study published Nov. 4, 2026, in Neurology, News-Medical reported. Each additional year of reproductive lifespan also cut the odds of having two or more signs of the disease by 8%, brainhealth.com reported.
The study, led by Anna Marseglia, PhD, of Karolinska Institutet in Stockholm, followed 352 women who were 70 and free of cognitive impairment when they enrolled. Researchers scored scans for four markers of cerebral small vessel disease—white matter hyperintensities, microbleeds, lacunes, and moderate to severe enlargement of spaces around blood vessels. The condition damages tiny vessels in the brain and is associated with stroke, cognitive impairment and dementia.
Among participants, 73% had used birth control pills and 61% had used or were using menopausal hormone therapy. After adjusting for education, high blood pressure and heart disease, the hormone therapy group showed fewer microbleeds and enlarged spaces around blood vessels. The average reproductive lifespan was 37 years; after accounting for education, pregnancies and breastfeeding, longer spans corresponded to the 8% reduction in odds.
Combined Hormone Use Shows the Strongest Association
Women who used oral contraceptives during their reproductive years and later received menopausal hormone therapy showed the most favorable vascular brain health, ua.news reported. Compared with women who had never used hormonal therapies, this group showed the least cerebral small vessel disease and the best white matter integrity.
Greater integrity of the brain’s white matter microstructure—an early indicator of healthier brain tissue—was linked to both birth control pills and menopausal hormone therapy. “What was particularly striking was that the most favorable vascular brain health was observed among women who had used oral contraceptives during their reproductive years and later received menopausal hormone therapy,” Marseglia said.
Association Only: Why the Study Cannot Prove Cause and Effect
The findings show an association, not proof that hormone use directly leads to better brain health; establishing that would require clinical trials. Marseglia noted that estrogen is known to have protective effects on neuronal cells and blood vessels, but its role in women’s cerebrovascular health in later life has been largely understudied.
Limitations include self-reported hormone exposure, which may suffer from recall inaccuracy, and the absence of tracked hormone levels over time. Because all participants were cisgender women, the findings may not apply to all women.
Does Hormone Therapy Actually Prevent Brain Blood Vessel Disease?
Does hormone therapy cause better brain health?
No. The study is observational and identifies statistical associations only. Clinical trials would be required to prove cause and effect, according to the researchers.
What is cerebral small vessel disease?
It affects tiny blood vessels within the brain and is associated with stroke, cognitive impairment and dementia, according to the American Academy of Neurology.
Who participated in the study?
The study included 352 cisgender women in Sweden who were 70 years old and without cognitive impairment at enrollment. The researchers noted the findings may not apply to all women.
“This suggests that hormonal factors acting across different stages of a woman’s life may have cumulative associations with cerebrovascular health in older age,” Marseglia said.
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