As we get older, we become more at risk of developing ‘multimorbidity’ – that’s multiple health problems including heart disease, stroke and dementia.
One-quarter of the Australian population have two or more chronic conditions.
Previous research found that many of these overlap, either directly or due to shared risk factors. A paradox has been that while men are more likely to have these ‘multimorbid’ conditions and which significantly contribute to dementia risk, women are at higher risk of dementia compared to men.
New research from Monash suggests that menopause might play a role.
Researchers examined 12 years of data from over 36,000 people in the UK Biobank and this included age, general health, lifestyle factors, sex, menopausal status and diabetes.
They examined brain and heart scans of the participants and checked blood pressures, waist-to-hip ratios, blood tests looking for a gene known to be linked with dementia (APOE-e4) and performed cognitive and memory tests – trying to work out which factors were most associated with developing dementia.
The researchers found that men at risk were more likely to be former or current smokers, have higher waist-to-hip ratios, diabetes, raised blood pressure and cholesterol, as well as having a history of ischaemic heart disease and stroke. None of this is surprising. But in women destined to develop dementia, the risk seemed to jump after the menopause, allowing for age. After menopause ,fat can start to be distributed in a male pattern, increasing the risk of heart and metabolic diseases much like men but at an older age.
Women also did more poorly than men when it came to changes in brain volume over the years – after they went through menopause. This suggests that it is not only the increased cardiometabolic risk that occurs post-menopause that contributes to a woman’s increased risk of dementia. The explanation might lie in female hormones.
The hormones that are present prior to menopause (specifically oestrogen) help protect women against cardiometabolic disease as well as the brain more directly, by regulating the proteins that drive dementia and having an anti-inflammatory effect. It seems that following menopause, the brain can suffer a double hit from the loss of oestrogen, worsening the risk of cardiometabolic disease and losing the direct protective benefits of oestrogen.
The bottom line is that the menopause doesn’t cause dementia but in women at risk of dementia, it speeds up damaging processes. The message is that women need to be more assiduous than men in getting significant exercise, learning new skills, keeping their weight down and eating a bioactive diet like the Mediterranean diet.