Published on August 25, 2026 in JAMA Network Openthis work does not say that early menopause causes Alzheimer’s. He suggests that it could constitute a signal allowing earlier action on certain factors of brain aging.
Menopause could leave a mark on the brain
Menopause doesn’t just mark the end of periods. With the gradual cessation of ovarian activity, exposure to reproductive hormones, particularly estrogen, decreases. However, these hormones participate in the functioning of brain cells, the health of vessels and the regulation of inflammation.
To measure the possible impact of this transition, Riley M. Bove and Maria Pia Campagna, neurologists at the University of California San Francisco (UCSF), analyzed data from
2,603 womenaged on average 78.3 years at the start of the study. Coming from two large American cohorts, they were followed for up to 18 years oldwith cognitive tests carried out each year (in particular episodic memory, that is to say the ability to remember events experienced, but also general thinking skills). The researchers also collected their reproductive history: age of first menstruation, age of menopause and natural or surgical nature of the latter.
The result is regular: the earlier menopause occurred, the more rapid the decline in cognitive abilities and episodic memory. The women affected were also diagnosed with Alzheimer’s earlier.
According to statistical models, menopause occurring
ten years ago was associated with approximately
2% acceleration in the onset of Alzheimer’s per decadeor close to 1.8 fewer years of disease-free life around the estimated mean age of diagnosis, 88.4 years.
A figure which obviously cannot predict the destiny of a woman. But it becomes significant when it is repeated on several thousand participants.
It’s not necessarily the neurons that tell the whole story
The researchers then sought to understand what could be happening in the brain.
At the house of 774 womenMRIs repeated every two years made it possible to measure brain volume and
white matter hyperintensitiesthese spots visible on imaging which indicate in particular lesions linked to small cerebral vessels.
Here lies one of the most interesting results of the study.
In the event of natural menopause, a woman whose periods stopped five years earlier accumulates, according to calculations, approximately
15% additional white matter lesions over ten years than another of the same age, a link not found after surgical menopause.
In contrast, the decrease in total brain volume was only very weakly associated with age at menopause. And the analyzes carried out after the death of 1,287 participants did not find a significant link between the age of menopause and the quantity of plaques or lesions typical of Alzheimer’s disease.
In other words, the observed phenomenon could better reflect
aging of small cerebral vessels
than a simple “shrinkage” of the brain or the classic Alzheimer’s process.
Natural menopause or surgery: not all stories are the same
The study, however, reveals another important nuance. Women who have undergone surgical menopauseparticularly after ovarian removal, had stronger associations with cognitive decline and earlier onset of Alzheimer’s.
The difference is biologically plausible.
During natural menopause, the reduction in hormonal production gradually sets in. When it is surgically induced by removal of the ovaries, the hormonal drop is much more brutal.
The researchers observed that women who experienced earlier menopause presented, over time, “more marked cognitive changes, earlier onset of Alzheimer’s disease and more white matter lesions” than those whose menopause occurred later, explains Riley M. Bove at PsyPost.
For the researcher, this observation could support the hypothesis according to which Longer exposure to reproductive hormones could help preserve brain health.
But it does not yet allow us to conclude that hormones alone constitute the key to the explanation.
Because a question remains: is early menopause directly involved in brain aging or does it rather constitute a marker of more general biological aging?
Current data does not allow us to decide.
Early menopause does not condemn you to Alzheimer’s
Caution remains essential. This study is
observational : it shows an association, but does not allow us to affirm that early menopause causes brain aging or Alzheimer’s disease.
Other factors could be involved. Early natural menopause could in particular be a marker of more general biological aging. The more marked results observed after surgical menopause, however, provide an argument in favor of a possible hormonal role.
The question of a possible protective effect of hormonal treatments for menopause also remains without a definitive answer.
Above all, researchers refuse to make it a new source of anxiety.
“This study is not intended to alarm women. A majority of women go through menopause and maintain their brain health throughout their life after menopause.”recalls Riley M. Bove to PsyPost.
Perimenopause, a time when it is still possible to act
For scientists, perhaps the most important message lies here: the period preceding menopause could become a window of prevention.
“Rather than alarming women, we would like to encourage them to view perimenopause as a window of opportunity.”explains Riley M. Bove to PsyPost.
The idea is to take advantage of this period to identify the modifiable factors likely to impact brain aging: high blood pressure, smoking, sleep, physical activity or mental health.
Early menopause would therefore not be a condemnation. It could rather constitute a sufficiently early warning signal to allow more careful management of cardiovascular and cerebral health.
This is perhaps the real change in outlook brought by this study: finally considering menopause not as a simple reproductive stage, but as a key moment to preserve women’s health well beyond their last period.