Common Health Factor in Women May Raise Dementia Risk, Study Finds - Newsweek

Women who go through menopause earlier in life may face a faster decline in brain health and a heightened risk of Alzheimer's disease decades later, according to new research that tracked thousands of women for nearly 20 years.

The study, published in JAMA Network Open, found that the age at which a woman reaches menopause is linked to the pace of her cognitive decline, her risk of developing Alzheimer's disease, and measurable changes in her brain structure over time.

Dr. Nikki Ramskill, a women's health doctor, menopause specialist and founder of The Female Health Doctor Clinic, told Newsweek the findings reframe how menopause should be understood.

"What I think is particularly important about this study is that it shifts the conversation about menopause away from seeing it as a collection of symptoms that just need managing for a few years," Ramskill said. "Menopause is a significant biological transition, and the age at which it happens may give us valuable information about a woman's health decades into the future."

She said the results carry particular weight for women with premature ovarian insufficiency, a condition in which ovarian function is lost or becomes intermittent before age 40.

"These women may potentially experience decades more of reduced oestrogen exposure than someone reaching menopause at the usual age," she said, adding that such women are generally advised to take hormone replacement therapy until at least the average age of natural menopause, around 51.

However, Ramskill cautioned against alarm.

"Earlier menopause does not mean that a woman is destined to develop Alzheimer's disease, and this study shows an association rather than proving that loss of oestrogen directly causes dementia," she said.

She also stressed the findings should not be used to justify prescribing HRT to all women specifically to prevent dementia.

Researchers analyzed data from 2,603 older women enrolled in two long-running studies, the Religious Orders Study and the Rush Memory and Aging Project, tracking participants for up to 18 years with annual memory tests and clinical evaluations.

Women who reached menopause earlier showed faster overall mental decline, particularly in episodic memory, and developed Alzheimer's disease at a younger age. Reaching menopause 10 years earlier translated to roughly 1.8 fewer Alzheimer's-free years at the average age of diagnosis.

Among 774 women who underwent repeated high-resolution MRI scans, earlier natural menopause was linked to a faster buildup of white matter hyperintensities—spots on brain scans indicating wear on the brain's white matter pathways.

Women who reached natural menopause five years earlier accumulated about 15 percent more of this damage over a decade than women who did not. The effect was specific to natural, gradual menopause rather than surgically induced menopause.

Researchers noted that women in their 60s are nearly twice as likely as men to develop Alzheimer's disease, a gap that cannot be explained by longevity alone. Menopause marks the loss of estrogen, a hormone linked to brain function, energy metabolism and inflammation control, which may help explain the disparity.

Ramskill said the findings point to an opportunity rather than a warning.

"We potentially have decades in which to address other modifiable dementia risk factors—including blood pressure, cholesterol, metabolic health, smoking, exercise, sleep and social and cognitive activity," she said.

Campagna, M. P., et al. (2026). Age at Menopause and Brain Atrophy Among Older Women. JAMA Network Open. doi:10.1001/jamanetworkopen.2026.30973.

Contact Newsweek editor on this story: Edward Pearcey.