# Does Early Menopause Increase Dementia Risk?
Research suggests that women who experience menopause at an earlier age may face a higher risk of developing dementia later in life. A study published in the Journal of Alzheimer’s Disease found that women who entered menopause at age 49 or younger had an 80 percent increase in dementia risk compared to women who reached menopause at the reference age of 50 to 51.
The connection between early menopause and dementia risk appears to be linked to lifetime estrogen exposure. Estrogen is a hormone that plays an important role in brain health and function. When women experience menopause earlier, they have fewer years of natural estrogen production, which may affect how their brains age and develop.
Brain imaging studies have provided physical evidence supporting this connection. Researchers analyzing MRI scans discovered that women who experienced menopause before age 50 had significantly smaller hippocampal volumes compared to those who reached menopause at age 50 or 51. The hippocampus is a brain region crucial for memory and learning, and its size has been associated with cognitive function and dementia risk.
The research also examined other factors related to lifetime estrogen exposure. Women who had given birth to at least one child showed greater total brain volume than those without children. Those with three or more children demonstrated even greater brain volume and less deterioration in regions vulnerable to Alzheimer’s disease. The use of hormone replacement therapy was associated with approximately a 47 percent lower dementia risk compared to women who never used these therapies.
However, more recent research presents a different perspective on hormone replacement therapy. A comprehensive review commissioned by the World Health Organisation and published in December 2025 analyzed data from multiple studies involving over 1 million participants. This review found no significant association between menopause hormone therapy and dementia risk, either positive or negative. The researchers examined various factors including the timing, duration, and type of hormone therapy used, but none showed meaningful effects on dementia development.
The discrepancy between these findings highlights an important limitation: the earlier study was observational, meaning it could identify associations but could not definitively prove that estrogen exposure directly causes better brain health. Additionally, the data relied on participants’ memories of when they experienced menopause, which can introduce errors in recall.
Researchers emphasize that early menopause should be considered an important factor when investigating dementia risk, particularly because it represents a modifiable aspect of women’s health history. However, the evidence regarding hormone replacement therapy as a protective treatment remains unclear and requires further investigation through high-quality, long-term studies.
Sources
https://www.ucl.ac.uk/news/2025/dec/menopause-hormone-therapy-does-not-appear-impact-dementia-risk
https://pubmed.ncbi.nlm.nih.gov/41435512/?fc=None&ff=20251224120350&v=2.18.0.post22+67771e2
https://pubmed.ncbi.nlm.nih.gov/41434897/?fc=None&ff=20251225110642&v=2.18.0.post22+67771e2
