In recent months, popular menofluencers on social media have made no shortage of alarming claims about what happens to women’s brains in menopause – including that they eat themselves.
When a study last month showed a loss of grey matter volume during menopause, headlines extrapolated further, claiming a link between menopause and dementia. Understandably, this caused a bit of panic.
The study in question looked at the emotional and cognitive effects of menopause and whether MHT made any difference. Cambridge university researchers analysed UK Biobank data from 125,000 women aged 40-69. They also had brain MRIs for some 11,000 participants.
The study compared three groups – pre-menopausal women, post-menopausal women who had used MHT, and post-menopausal women who had never used MHT—across several outcomes, including depression and anxiety, tiredness and sleep, cognition and brain structure.
The study found significant reductions in grey matter volume in three key brain regions involved with memory and emotion in post-menopausal women compared to pre-menopausal women – and MHT did not appear to mitigate this.
Menopause was associated with increased levels of anxiety, depression, and sleep difficulties including tiredness, insomnia and sleep duration – and again, MHT didn’t counteract this.
In fact, post-menopausal women who had used MHT were more likely to have seen a GP or psychiatrist for “anxiety, nerves or depression,” and had higher levels of depression compared to those who had not used it (and compared to those who hadn’t gone through menopause). Those taking MHT were also more tired.
Following post-hoc analysis, the researchers concluded that those “who have psychiatric symptoms are more likely to be prescribed HRT [MHT] than those who do not report mental health symptoms.”
The authors noted that depression itself could increase the risk of dementia and that it was difficult to separate out whether women with poorer mental health are more likely to be prescribed MHT, or if their mental health worsens because of it. However, their post-hoc analysis indicated the former, that “women with pre-existing mental health problems are more likely to be prescribed HRT [MHT], suggesting that they may have had poorer mental health at baseline.”
When it came to cognition, the researchers found no effect of menopause or MHT on memory, but found reaction time was slower in post-menopausal women not taking MHT compared to the pre-menopausal group – but there was no difference between the MHT and pre-menopausal groups.
Pauline Maki, a professor of psychiatry, psychology and obstetrics and gynaecology at the University of Illinois at Chicago, and one of the world’s leading researchers on menopause and the brain, offers reassurance.
“Your brain is not shrinking – it’s adapting,” says Professor Maki, who is currently conducting the longest running longitudinal study on the changes that happen across the menopause transition.
She says that while the UK Biobank is a great resource generally, it’s not set up to study menopause, making this particular study “fundamentally flawed.”
For example, asking people if they’ve had a period on the past 12 months is not always a good indicator of post menopause as there are many reasons why women may not be menstruating, including endometrial ablation or hysterectomy without removal of the ovaries. Asking if people have ‘ever’ or ‘never’ used hormone therapy gives no indication of what types they used or how long they used it for, she adds.
(The researchers calculated duration by subtracting the age MHT was started from the woman’s age at assessment.)
Moreover, it’s hugely difficult to separate age-related changes from other causes, but so far Professor Maki and her colleagues have not noted any significant changes as a result of menopause in their studies.
She says both men and women have significant amounts of brain volume loss as we age and her latest work, presented at the Menopause Society conference, but not yet peer reviewed, showed there were around “120 different areas that were getting smaller. And this is normal aging. And then we asked the question, what about menopause stage? Nada. Nothing. There wasn’t a signal. There wasn’t a trend. There wasn’t any signal related to whether a woman was pre-, peri- or post-menopausal.”
Professor Maki says this lack of a trend relating grey matter volume loss to menopause stage is important, because modifying age-related changes requires a different approach. In utero maternal health, early childhood trauma, stress, nutrition, mental health, physical activity and other lifestyle factors all play a role in brain health.
“To measure menopause, you have to measure the aging of the ovary. You need to follow women from pre to peri to post menopause. You need menopause stage. And if something changes with advancing menopause stage, then you think, okay, that could be menopause, as long as it can’t be explained by age,” Professor Maki says.
“Now, in our study, we found that age affected brain size in many, many areas of the brain, but menopause stage did not. Reassuring news. In the UK Biobank study that we’re hearing about, they didn’t have pre-, peri- and post-menopausal stages, so they couldn’t answer questions about what happens to the brain.”
The researchers looked at grey matter volume in the hippocampus, which is responsible for forming and storing memories, the entorhinal cortex, which is the ‘gateway’ for passing information between the hippocampus and the rest of the brain, and the anterior cingulate cortex which helps with managing emotions, decision-making, and focusing attention.
While the study was not about dementia or the role of MHT in preventing it, senior author Professor Barbara Sahakiandid discuss Alzheimer’s disease in the accompanying press release.
“The brain regions where we saw these differences are ones that tend to be affected by Alzheimer’s disease. Menopause could make these women vulnerable further down the line. While not the whole story, it may help explain why we see almost twice as many cases of dementia in women than in men,” Professor Sahakian said.
Misleading headlines followed – and many women have expressed concern.
Some 56% of 340 respondents to an online poll by the Menopause Research and Education Fund worried they were now at increased risk of developing Alzheimer’s disease – while 28% said they weren’t worried and 16% were confused and couldn’t say either way.
Dr Sarah McKay, a neuroscientist and science communicator who authored the Women’s Brain Book, says that while the difference in volume loss was statistically significant in all three brain regions, it’s important to keep things in perspective.
“The volume loss is equivalent to around 1/30th of a teaspoon over 15 years which is probably in line will healthy ageing anyway,” Dr McKay says. “The actual grey matter volume difference is way less than you see with nine months of pregnancy.”
What about the effect of menopause on dementia/Alzheimer’s risk?
Professor Maki says those who have vasomotor symptoms, especially if they are affecting their sleep, are at particular risk and their symptoms should be treated with either hormonal or non-hormonal medications.
It’s not oestrogen loss itself that increases the risk of dementia, she argues, but rather the consequences of oestrogen loss that can occur at menopause, such as sleep disruption, mood disturbances, changes in cardiovascular health, body weight and metabolism.
Treating those symptoms is “the key to maintaining our brains,” she says.
“Because, after all, 27% of women sail through menopause without any problem. We published a study showing that only 20% of women show significant cognitive issues during the menopause transition, and others even get better during the menopause transition. So, my menopause is not your menopause, and symptoms have a lot to do with it.”
Sleep apnoea or snoring that disrupts sleep is another risk factor, not just for heart health and stroke risk, but also for dementia. Combine that with untreated hot flushes and you’ve got a perfect storm.
Sleep problems can continue for years, even decades – and not surprisingly, this negatively impacts mood, she adds.
Her take home message? Cognitive lapses are a normal part of menopause. They’re not dementia.
“What’s happening is your brain is adjusting to changes in sex steroid hormones. It’s rewiring itself,” Professor Maki says. However, symptoms such as hot flashes do impact brain health, so effective, evidence-based treatments such as MHT or newer non-hormonal options are key, she emphasises.
For more information
Zuhlsdorff K et al. Psychological Medicine. 2026;56:e24.
You can watch the full interview with Professor Maki here.
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