Dementia risk raised by earlier menopause claims research report
LONDON: Hormone changes during the menopause may explain why women are more likely to get dementia than men, research has suggested.
Women who go through early menopause were found to be more likely than men to suffer memory loss in old age, but these sex differences did not apply in women going through late menopause. This suggests that the risk of dementia is strongly linked to oestrogen, the female sex hormone, which has a protective effect on the brain and levels of which fall dramatically during the menopause.
Nearly twice as many women as men develop Alzheimer’s disease, and experts said the age of menopause should now be considered a key risk factor for the disease.
A study by the University of Toronto looked at 8,360 women, with an average age of 65, whose memory was compared with that of 8,360 men of the same age. The participants had a series of memory and brain health tests over a three-year period, as well as checks including blood pressure and cholesterol to determine their heart health, which is another key risk factor for dementia.
The women were asked what age they began menopause and were divided into three groups — early menopause, between ages 35 and 48; average menopause, between ages 49 and 52; and later menopause, between ages 53 and 65.
Women who had an earlier menopause tended to score worse on memory tests and have poorer cardiovascular health, compared both with men of the same age and women who went through menopause later.
The memory of women who went through menopause at an average or late stage was no worse than that of men. Across all groups, poorer cardiovascular health was associated with a greater risk of vascular dementia, which is caused by poor blood flow to the brain.
The research, published in the journal Neurology, said that earlier menopause “may increase female susceptibility to the detrimental effects” on the brain of poor heart health, explaining sex differences in dementia risk. Oestrogen has been shown to protect brain health by blocking some of the harmful effects of substances involved in Alzheimer’s disease and helping to clear toxic plaque from the brain.
Dr Jennifer Rabin, the lead author, said: “While cardiovascular risk factors are known to increase a person’s risk for dementia, what is lesser known is why women have a greater risk for Alzheimer’s disease than men.
“We examined if the hormonal change of menopause, specifically the timing of menopause, may play a role in this increased risk. We found that going through this hormonal change earlier in life while also having cardiovascular risk factors is linked to greater cognitive problems when compared to men of the same age. Our study suggests that earlier menopause may worsen the effects of high cardiovascular risk on cognitive decline.”
