A new study may explain why women are more at risk of dementia than men

Our bodies experience many physical and mental changes during menopause, and our brain is just one of the organs affected. Last week, headlines flew up about new research that revealed some of the changes in women's brains in menopause are similar to those in people with dementia.

A team from Cambridge University looked at the impact of menopause and hormone replacement therapy (HRT) on women’s mental health, cognitive function, and brain structure. In the study, published in Psychological Medicine, they used data from almost 125,000 women in the UK Biobank to examine whether menopause is associated with grey matter loss.

Along with common perimenopausal and menopausal symptoms of anxiety, depression and sleep problems, scans showed that parts of the brain were smaller in post-menopausal women compared to pre-menopausal women. The lowest volumes were recorded in the HRT group.

Researchers saw changes in the hippocampus, entorhinal cortex and anterior cingulate cortex (ACC) - all areas important for memory, emotional regulation, and focus. They are also areas affected by Alzheimer’s disease, the most common cause of dementia.

The authors say: “Our findings suggest that menopause is linked to adverse mental health outcomes and reductions in grey matter volume in key brain regions. The use of HRT does not appear to mitigate these effects and may be associated with more pronounced mental health challenges, potentially due to underlying baseline differences.

“These results have important implications for understanding the neurobiological effects of HRT and highlighting the unmet need for addressing mental health problems during menopause,” they add.

They say that the results could help explain why many more women suffer from dementia than men, and help women ask for help when it comes to experiencing mental health, memory or mood problems later in life.

What's the link between menopause and dementia?

If you take the headlines at face value, it may look like the research suggests that taking HRT increases the risk of mental health issues after menopause and increases the risk of grey matter loss, which is linked to dementia. However, experts warn this isn't the case at all.

The research didn’t take into account the types of HRT the women were taking, and many of the women using HRT reported having mental health issues before starting the medication.

Dr Charis Chambers is a board-certified OB/GYN and the chief medical officer at Clue. She told woman&home: "This study doesn't have enough evidence to show that HRT affected anything, really.

"It showed that women using HRT reported greater mental health challenges than post-menopausal women not using HRT. It also showed that grey matter volumes are smaller in postmenopausal women compared to premenopausal women, with the lowest volumes observed in the HRT group.

"This is an association and may be explained in part by analyses which showed higher levels of pre-existing mental health symptoms in women who are prescribed HRT.

"Women with pre-existing mental health symptoms may be at greater risk of greater mental health challenges in menopause, which would make them more likely to seek treatment and ultimately be prescribed HRT. It’s also possible that grey matter generally decreases in menopause, and those with more pronounced mental health challenges have more brain differences due to their underlying baseline difference."

If you are already taking HRT or feel it could help with your symptoms, and have spoken to a doctor who is happy to prescribe it to you, there's no reason to stop based on this study.

"The benefits of HRT are well established," says Dr Chambers. "It provides effective relief of vasomotor symptoms, reduces osteoporotic fractures, and treats genitourinary syndrome [vaginal dryness, burning, itching] of menopause. The evidence in this study isn’t enough to support the need to 'balance' symptom management with any worsening of mental health status or grey matter volume.

"The general approach to HRT, however, is a very customised balance of risks and benefits with conservative dosing practices and frequent reassessment. This should be the standard, which is why it’s so important to see a provider who is well-versed in the risks, benefits, and management guidelines of HRT."

What about HRT?

"Menopause and low hormones are key risk factors for dementia, and the results of this study may confuse people if they are not interpreted properly," agrees Dr Louise Newson, a menopause specialist.

"There is good evidence that women taking body-identical hormones can reduce their dementia risk, and this should not be ignored," she told us. "Many women, especially in the past, have been taking synthetic types of both oestrogen and progesterone, which can have negative effects on brain function. These synthetic hormones have very different biological effects on the brain compared to our natural hormones - progesterone, estradiol and testosterone - which are actually made in our brains and have many important functions, including improving cognition and memory."

It’s thought that oestrogen can protect the brain from the harmful effects of the amyloid-β protein, which builds up when you have dementia and causes brain cells to die or become damaged.

The Alzheimer’s Society says women account for an estimated 65% of people who currently have dementia in the UK. While the reasons for this aren’t clear, research is looking at whether the fall in oestrogen during menopause is a contributing factor, especially as Alzheimer’s is more common in women after menopause.

Some key ways to lower your dementia risk include staying physically active, not smoking, limiting alcohol and eating well to maintain healthy cholesterol and blood pressure levels.

When it comes to HRT, it’s worth remembering that for many women, the benefits of taking it outweigh the risks. The medication can help with symptoms such as insomnia, hot flashes, mood swings and vaginal dryness. It can also lower your risk of osteoporosis by increasing oestrogen levels, which will protect your bones and muscles for longer.

As always, speak to your GP if you have any questions or concerns.