A recent study from Japan has found that women who go through menopause before the age of 40 are more likely to experience memory and thinking problems later in life, compared to women who reach menopause after age 50.
The study was published on April 15, 2025, in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. These results suggest that early menopause may be a warning sign of higher risk for future cognitive decline and possibly dementia.
The research was conducted by a team from the Tohoku University Graduate School of Medicine and the Tokyo Metropolitan Institute of Medical Science. They were motivated by the fact that dementia affects more women than men around the world.
While part of this may be due to women living longer, the team suspected there might be female-specific risk factors involved—one of them being early menopause.
Menopause marks the natural end of a woman’s menstrual cycles, usually occurring around the age of 50. But for some women, it happens much earlier—before age 40—which is known as early or premature menopause.
Earlier menopause is already linked to higher risk of depression in later life, and depression itself is a known risk factor for dementia. However, there hasn’t been much research directly connecting early menopause with long-term memory and thinking skills.
To study this, the researchers used data from the English Longitudinal Study of Ageing, a long-term health study based in the UK. They looked at a group of over 4,700 women and over 4,200 men.
They divided the women into three groups based on when they reached menopause: before age 40, between 40 and 49, and 50 or older. Then, they measured their cognitive performance—how well they could remember words, stay oriented, and think quickly—two years later.
The team carefully adjusted their analysis to remove the effects of other known risk factors for dementia, such as smoking, physical inactivity, and depression. “We wanted to make sure that any link we found between early menopause and poor memory wasn’t simply due to other risk factors like depression,” explained lead author Dr. Miharu Nakanishi from Tohoku University.
After making these adjustments, they found that women who experienced menopause before age 40 had significantly worse scores in orientation, as well as short-term and long-term memory recall, compared to women who reached menopause at age 50 or older.
Interestingly, women who entered menopause later (age 50 or older) even outperformed men in these cognitive tasks. The use of hormone replacement therapy (HRT), a common treatment for menopausal symptoms, did not appear to influence memory or thinking skills in this study.
This research suggests that early menopause may itself be a direct risk factor for cognitive decline, even when depression and other factors are taken into account. The findings could help doctors identify women who may be more likely to experience memory loss or dementia as they age.
Dr. Nakanishi emphasized that more research is still needed to understand why early menopause affects the brain this way. It may be related to the sudden drop in estrogen and other female hormones, which play a role in brain health. “Understanding this relationship in more detail could lead to new strategies for delaying dementia in women at higher risk,” she said.
In the meantime, these results highlight the importance of tracking reproductive health history as part of assessing dementia risk. For women who experience menopause unusually early, it might be helpful for healthcare providers to monitor their cognitive health more closely over time.
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The research findings can be found in Alzheimer’s & Dementia.
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