We know that women are more likely than men to develop dementia.
But understanding exactly why has proved far more complicated.
For years, researchers have explored the role of ageing, genetics and differences in life expectancy.
Now, scientists are investigating whether something else could help explain the difference: the way women's brains change during menopause, how their immune systems behave and how they respond to early brain changes.
And some of the findings are particularly interesting.
What Does Menopause Have to Do With Brain Health?
A large study from the University of Cambridge analysed brain scans from nearly 125,000 women.
Researchers found that menopause was associated with reductions in grey matter in areas of the brain involved in memory, attention, emotion and decision-making.
Some of these areas are also particularly vulnerable to Alzheimer's disease.
But there's an important distinction to make.
This doesn't mean menopause causes dementia.
Instead, researchers believe menopause may represent an important period of neurological change that could influence brain health later in life.
The Possible Role of Oestrogen
One explanation scientists are exploring involves oestrogen.
We often think about oestrogen in relation to reproductive health, but the hormone also plays a role in how the brain functions.
In particular, it helps brain cells use glucose for energy.
As oestrogen levels fall during menopause, the brain may become less efficient at using that glucose.
Researchers are investigating whether this change could place additional stress on areas of the brain that are already vulnerable to Alzheimer's disease.
It's an interesting possibility, but it doesn't mean every woman experiencing menopause is at increased risk of developing dementia.
There are many factors involved, and the relationship is still being studied.
Could Women's Immune Systems Play a Part?
Another area of research focuses on the immune system.
Women generally have stronger immune responses than men.
This can be beneficial when fighting infections, but it may also contribute to a greater susceptibility to inflammation and certain autoimmune conditions.
Researchers are exploring whether these differences could influence what happens in the brain as we age.
It's another reminder that dementia risk isn't necessarily explained by one single factor.
Women's Brains May Also Be More Resilient
Interestingly, some research suggests women may initially be better at compensating for certain changes in the brain.
Women often perform better on verbal memory tests and may maintain these abilities even when early changes are taking place.
That could mean noticeable symptoms sometimes appear later, despite underlying changes already developing.
Researchers are still working to understand what this means for diagnosis and how cognitive changes are recognised.
What Is Cognitive Reserve?
There's another important concept in brain health called cognitive reserve.
Put simply, it's the brain's ability to continue functioning despite changes associated with ageing or disease.
Activities that challenge the brain throughout life may help build this reserve.
That includes education, learning new skills, intellectually stimulating work, physical activity and staying socially connected.
It doesn't mean someone can completely protect themselves against dementia.
But it highlights why keeping our brains engaged throughout life matters.
What Should Women Take Away From This Research?
Perhaps the most important message is that menopause shouldn't be treated as a warning that dementia is inevitable.
For most women, menopause is a normal life transition, and experiencing symptoms such as forgetfulness or difficulty concentrating doesn't automatically mean dementia is developing.
However, it may be a useful opportunity to think about long-term brain health.
Staying physically active, maintaining social connections, prioritising sleep and continuing to learn new things are all worthwhile habits.
And if memory difficulties or cognitive changes are persistent, worsening or affecting everyday life, speak to a healthcare professional rather than simply assuming they're part of menopause or ageing.
Understanding why dementia affects women differently could eventually help researchers improve how the disease is recognised and treated.
For now, the encouraging message is that brain health deserves attention at every stage of life.
