Sex, menopause and dementia risk
Risks of dementia associated with menopause
A major difference between older men and women is the menopause. This is when levels of sex hormones, such as oestrogen and progesterone, fall dramatically in women during late middle age.
Oestrogen is thought to have a range of protective effects on brain health, including an ability to block some of the harmful effects of substances involved in Alzheimer’s disease.
This has led some researchers to suggest that if a person has more exposure to oestrogen throughout their life, they might be less likely to develop dementia. For example, if they:
- start periods at a younger age
- have at least one pregnancy (when levels of oestrogen are greatly increased)
- start menopause later.
By contrast, a very early menopause caused by surgical treatments for cancer may increase the risk of dementia in later years.
We also now know that most of the diseases causing dementia start developing in the brain around 10-20 years before clinical symptoms show, which for many women is around the time of their menopause.
It’s tempting therefore to connect the loss of this brain-protecting hormone with the start of processes in the brain that ultimately lead to dementia.
However, the relationships between sex, menopause and dementia risk are extremely complex and until recently researchers have not prioritised menopause as an opportunity to learn more about dementia. We need a lot more research before we can draw any firm conclusions.
