You walk into a room and forget why. A word you use every day disappears mid-sentence. You're sleeping badly, your mood is up and down, and somewhere in the back of your mind a question forms: is this menopause, or is it something more?
It's a common worry, and an understandable one. Women make up the majority of people living with Alzheimer's. At the same time, "brain fog" is one of the most talked-about symptoms of perimenopause. So it's natural to wonder whether the two are connected.
The honest answer is that researchers are still working it out. This article covers what the evidence shows so far, what it doesn't, and what you can do now that's supported by good evidence.
Why Researchers Are Looking at Menopause
Dementia affects women more than men. The Alzheimer's Association reports that almost two-thirds of Americans living with Alzheimer's are women. The World Health Organization notes that women are disproportionately affected by dementia, both as people living with it and as carers, providing around 70 percent of care hours.
Living longer is part of the explanation, but researchers don't think it's the whole story. Menopause brings big changes in oestrogen, which plays a role in the brain, so it has become one of the areas scientists are studying closely. Our article on how men and women experience dementia differently looks at the wider picture.
Menopause Symptoms and Later Thinking Skills
One of the more talked-about recent studies comes from Canada's CAN-PROTECT research program, published in PLOS One in 2025. Researchers looked at 896 post-menopausal women, with an average age of 64, who recalled which menopause symptoms they had experienced, such as hot flushes, night sweats, sleep problems, mood changes and difficulty concentrating.
Women who reported more symptoms tended to report more difficulties with everyday thinking skills later in life, and more "mild behavioural impairment," a set of mood and behaviour changes that researchers see as an early risk marker for dementia.
It's important to read this carefully:
It shows a link, not a cause. The study was cross-sectional, a snapshot in time.
Symptoms were recalled, sometimes many years later, which can be imprecise.
It measured risk markers, not dementia diagnoses.
So it doesn't mean a hard menopause will lead to dementia. It does suggest menopause symptoms are worth taking seriously, and it adds to the case for more research.
What About Brain Fog?
Many women notice memory lapses, trouble concentrating or word-finding problems during perimenopause. These changes are real, and they're common. Poor sleep, night sweats, anxiety and low mood can all make thinking harder on their own.
Brain fog during menopause is not the same as dementia. If the changes are making daily life difficult, getting worse over time, or you're worried, talk to your doctor. Our guide to early cognitive changes versus normal ageing can also help you think through what you're noticing.
Does Hormone Therapy Protect the Brain?
This is where a lot of confusion lives, and where the research is most often overstated online.
For years, some researchers proposed a "critical window" theory: that hormone therapy started close to menopause might protect the brain, while starting it much later might not, or might even raise risk. It's an interesting idea, but it hasn't been confirmed in clinical trials.
The most rigorous recent review, published in The Lancet Healthy Longevity in late 2025, pooled high-quality studies and found no evidence that menopause hormone therapy either increases or decreases dementia risk.
The authors concluded that hormone therapy decisions should be based on its other benefits and risks, not on dementia prevention. They also noted big gaps in the evidence, particularly for women with early menopause.
That's consistent with the Menopause Society's position that hormone therapy is not recommended at any age to prevent cognitive decline or dementia.
What this means in practice:
Hormone therapy can be a very effective treatment for menopause symptoms like hot flushes and night sweats, and for some women it helps sleep and quality of life.
It shouldn't be started, or avoided, because of dementia fears alone.
The right decision depends on your symptoms, age, time since menopause, and personal health history. That's a conversation for you and your doctor.
Keeping track of how you're feeling can make doctor's appointments more productive. Elli Cares includes simple daily wellbeing check-ins for logging symptoms and mood, and it can connect with Apple Health or Android Health Connect. When it's time for an appointment, a downloadable report helps you show patterns instead of trying to remember them on the spot.
What You Can Do Now
While the menopause question is still being studied, a lot is already known about protecting brain health. The 2024 Lancet Commission on dementia identified 14 potentially modifiable risk factors, and midlife is a key time to address many of them.
Look after your sleep. Poor sleep affects thinking day to day, and night sweats can make it worse. If symptoms are disturbing your sleep, that's a good reason to talk to your doctor about treatment. See our article on whether poor sleep increases dementia risk.
Take mood seriously. Depression is one of the Lancet Commission's risk factors. Menopause can bring anxiety and low mood, and both are treatable. Our piece on why emotional wellbeing matters for cognitive health goes further.
Keep moving. Physical inactivity is on the list too. Walking counts. Our guide to daily walks for brain health explains how much seems to matter.
Know your numbers. High blood pressure, high LDL cholesterol and diabetes in midlife are all risk factors. Menopause is a good time for a check-up.
Check your hearing and eyesight. Untreated hearing and vision loss are both on the Lancet list.
Stay connected. Social isolation is a risk factor, and friendships often get squeezed during busy midlife years.
Limit alcohol and don't smoke.
For a broader overview, see our five brain health tips for ageing.
Questions to Ask Your Doctor
Are my memory or concentration problems likely to be menopause-related?
Could sleep, mood or another condition be playing a part?
Is hormone therapy a good option for my symptoms, given my health history?
What else should I be checking, such as blood pressure, cholesterol or hearing?
When should I come back if things don't improve?
Frequently Asked Questions
Does menopause cause dementia?
There's no evidence that menopause causes dementia. Some research links a higher number of menopause symptoms with later changes in thinking and behaviour, but these studies show associations, not cause.
Is menopause brain fog a sign of dementia?
Usually not. Brain fog is a common menopause symptom, often linked to sleep, mood and hormonal changes. Talk to your doctor if changes are severe, getting worse or affecting daily life.
Does hormone therapy reduce dementia risk?
Current evidence doesn't show that it increases or decreases dementia risk, and guidelines don't recommend it for dementia prevention. It can be very effective for menopause symptoms.
Why do more women get Alzheimer's?
Women live longer on average, but researchers believe other factors, including hormonal changes, may also play a role. This is an active area of research.
A Reason to Pay Attention, Not to Panic
Menopause is a good prompt to look after your brain, not a reason to fear the future. The steps that help most are ones you can start today. To learn more about Elli, visit our Seniors and Families page.
