Oral contraceptives and HRT linked to healthier brain vessels in women

Women who used oral contraceptives or menopausal hormone therapy (MHT) displayed fewer signs of damage to the brain's small blood vessels, according to a new study published in Neurology. The research also identified a correlation between a longer reproductive lifespan and improved cerebrovascular health.

Alzheimer's Research UK, the leading dementia charity in the United Kingdom, characterized the findings as "interesting" while emphasizing that additional data is required. The study involved 352 women with a mean age of 70. It observed that participants with extended natural estrogen exposure from menarche to menopause showed less vascular damage.

Estrogen’s role in brain aging

The publication notes that women are disproportionately affected by Alzheimer disease (AD), a vulnerability potentially tied to estrogen fluctuations throughout life. Estrogen possesses neuroprotective and vasoprotective properties, suggesting that lifetime exposure may influence both AD-related neurodegeneration and cerebrovascular health.

Beyond reduced vessel damage, the research indicated stronger, healthier connections between different brain regions among those using hormonal therapies. Specifically, MHT users exhibited fewer markers of injury to small blood vessels. However, because the design was observational, the study cannot establish cause and effect.

Charity advises caution on treatment changes

Dr Honorine Lebraud, Senior Partnerships Manager at Alzheimer's Research UK, stated that the work builds on growing evidence regarding reproductive and hormonal history in relation to brain health during aging. She noted that nearly two-thirds of people living with dementia are women.

"While these findings are interesting, further research is needed to understand these patterns," Dr Lebraud said. She clarified that the study does not prove hormone exposure directly improves brain health or lowers dementia risk. Consequently, the charity’s advice remains unchanged: women should not start or stop taking the contraceptive pill or HRT based on these results to reduce dementia risk.

Decisions concerning hormonal treatments should continue to be made with a healthcare professional, guided by individual health needs. The study, titled "Reproductive Lifespan and Hormonal Therapy in Relation to Later-Life Neurovascular Health in Community-Dwelling Older Women," highlights limitations including self-reported binary estrogen exposure and the need for future studies on potential cognitive effects.