A new study has found that women are at greater risk of dementia if they enter menopause at an earlier age.
New research led by the University of Galway has tracked how certain reproductive and hormonal factors affect women’s risk of developing dementia.
The study found that early menopause is associated with a higher risk of dementia, while hormone replace treatment (HRT) is associated with a lower risk of dementia, and greater exposure to oestrogen over the reproductive lifespan is linked to better cognitive function, as is having more children.
Women have a higher risk of dementia than men. In Ireland, about 40,000 women and 25,000 men were living with the condition in 2020, with the total number expected to double by 2045 due to our ageing population.
‘Sex-related differences in dementia are poorly understood’
The fact that women live longer than men is considered an important factor in this sex difference, however, Prof Emer McGrath and an international team of researchers think there are other factors at play including reproductive health and hormonal levels that warrant further investigation.
Compared to cardiovascular diseases, sex-related differences in Alzheimer’s disease and related dementias are poorly understood, McGrath, who is lead author of the new study, tells SiliconRepublic.com.
McGrath, an associate professor of medicine at the University of Galway and a consultant neurologist at Galway University Hospital, has been researching dementia and other neurological conditions for more than a decade.
In this study, McGrath’s research team at Galway, along with colleagues at Boston University, were able to use data from more than 1,300 healthy women in the US who took part in the Framingham Heart Study, the world’s longest running longitudinal cohort study. About 15pc of study participants had Irish ancestry, McGrath says.
The study, which was published in the Journal for Alzheimer’s Disease, looked at the age the women first got their period and entered menopause, how many children they had, whether they used post-menopausal HRT and their oestrogen levels, and compared this data with signs of brain shrinkage on MRI scans, neurocognitive test results and whether they developed dementia.
One interesting finding was that women who had more children had larger brain volumes and better visuospatial skills in later life. As a mother of young children herself, McGrath says you need eyes in the back of your head so she is not so surprised by this finding.
Another finding was that earlier use of postmenopausal HRT was associated with improved cognitive performance compared to later use, suggesting that higher levels of oestrogen may have a neuroprotective effects in the early post-menopause years, and this warrants further investigation.
Overall, the study authors suggest that oestrogen may be a “modifiable target” to tackle dementia in women, but further research is needed. McGrath says next steps could include looking at hormonal levels more carefully and considering other factors such as reproduction via IVF and whether the woman breastfeeds.
There’s huge momentum is studying dementia and, in particular, sex-related differences, McGrath says. There has been an increase in funding and improved therapies for the condition and impetus to do more. “Now is an excellent time to work in the area.”
McGrath is also keen to stress that there are a number of lifestyle choices that everybody can implement to lower their risk of dementia. A healthy diet, regular exercise, taking steps to lower your blood pressure and quitting smoking all decrease dementia risk at any stage of life, she says.
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