Menopause and Dementia Risk: New Study Examines Brain Changes and HRT's Role
A groundbreaking new study from the University of Cambridge has revealed significant reductions in grey matter volume in women's brains during menopause, raising important questions about dementia risk and the protective potential of hormone replacement therapy. The research, published in Psychological Medicine, analysed data from nearly 125,000 women, including detailed MRI scans from 11,000 participants, providing unprecedented insight into how hormonal changes affect brain structure.
The Brain Fog Reality: When Menopause Mimics Dementia Symptoms
For many women experiencing menopause, cognitive symptoms like memory lapses, poor concentration, and that pervasive "brain fog" can be profoundly distressing. The Menopause Mandate 2025 Survey found that 86% of its 15,000 respondents reported experiencing brain fog, with many fearing these symptoms might indicate early-onset dementia. Professor Aimee Spector, a clinical psychology of ageing expert at UCL, explains that while these cognitive symptoms are most prominent during perimenopause, they typically improve post-menopause for most women.
"Brain fog can be very distressing, but it's not diagnosable," says Professor Spector. "People worry that it's dementia, and brain fog is the symptom most linked to stopping work, but for most women, it settles and improves post-menopause."
The HRT Dilemma: Protection or Placebo?
The Cambridge study, led by Professor Barbara Sahakian, showed reductions in grey matter volume in brain regions associated with emotional regulation, memory, and learning when comparing pre- and postmenopausal women. Interestingly, the research suggests that HRT doesn't appear to prevent this grey matter loss, though it may play a role in slowing psychomotor speed – essentially reaction time.
Study co-author Christelle Langley notes: "HRT does play a role in slowing psychomotor speed. This suggests that HRT may help to slow age-related declines in response speed." However, she emphasises that the data points only to a potential role for HRT in mitigating aspects of cognitive ageing, not preventing structural brain changes.
This nuanced picture becomes even more complex when considering contradictory research. Professor Spector's December 2025 meta-analysis in The Lancet Healthy Longevity showed no significant association between HRT and dementia risk or benefit, highlighting the need for more comprehensive research into this critical area of women's health.
When Cancer Complicates Menopause Management
For women like Alice Smellie, who was diagnosed with breast cancer in 2023, the menopause journey becomes particularly challenging. After finding significant relief from brain fog through HRT in her mid-forties, Smellie was advised to stop hormone therapy following cancer treatment, despite her cancer being triple negative and therefore not hormonal.
"My biggest fear was that without the protective effects of oestrogen, I was at higher risk of other conditions; osteoporosis, cardiovascular disease and – most frightening of all – Alzheimer's," Smellie explains. Her experience highlights the difficult decisions women face when balancing cancer recovery with long-term cognitive health.
Dani Binnington, founder of the support organisation Menopause and Cancer, observes that very few women return to HRT solely for dementia prevention. "It's usually for immediate symptoms as well as long-term health," she notes, emphasising the importance of comprehensive support for women navigating these complex health decisions.
Beyond Hormones: Lifestyle Strategies for Brain Health
Fortunately, research suggests multiple evidence-based approaches to support brain function during and after menopause. Christelle Langley emphasises that "there are a number of evidence-based healthy lifestyle habits that help to reduce our risk of dementia and may mitigate these menopause-related changes in brain health."
Key strategies include:
- Strength training at least twice weekly to significantly benefit brain health and cognitive function
- Reducing alcohol consumption, which damages blood vessels and destroys brain cells
- Following brain-healthy diets like the MIND diet, focusing on fruits, vegetables, nuts, seeds, whole grains, lean protein and olive oil
- Supporting gut microbiome health through diverse plant consumption, with emerging research suggesting links between gut bacteria and dementia risk
- Managing stress and prioritising quality sleep
Binnington recommends a holistic approach: "I always recommend not pinning hopes on one strategy, but looking for lots of solutions – sleep, stress, nutrition and exercise."
A Nuanced Future for Menopause and Brain Health
While the Cambridge study suggests a link between menopausal brain changes and dementia risk, experts emphasise that this represents just one piece of a complex puzzle. Professor Spector reminds us that "brains naturally decline decade by decade, so we'd expect them to look different in older women," putting menopausal changes in broader context.
For women concerned about dementia risk, the current evidence suggests that lifestyle interventions may offer substantial protection, while HRT's role remains uncertain and highly individualised. As research continues to evolve, women are encouraged to have open discussions with healthcare providers about their specific risks, symptoms, and prevention strategies.
Perhaps most encouragingly, recent studies suggest women's brains don't reach their prime until their late fifties – offering hope that the post-menopausal years can be a time of cognitive strength and resilience, regardless of hormonal status.
