January 2023 – By Kate Muir

There’s some good news at last around Alzheimer’s Disease: evidence is growing that taking hormone replacement therapy – particularly the body-identical kind – helps protect the female brain against dementia. This brings hope to around quarter of women, like me, who carry the APOE4 gene which can put you at risk of Alzheimer’s.

A new study from the University of East Anglia showed that HRT use is associated with better memory, cognition and larger brain volumes in later life among women carrying the APOE4 gene. The researchers looked at 1,178 women participating in the European Prevention of Alzheimer’s Dementia initiative – which was set up to study participants’ brain health over time.

They found that HRT was most effective when introduced early in the menopause journey during perimenopause. (Here’s the paper: www.uea.ac.uk/news/-/article/hrt-could- ward-off-alzheimers-among-at-risk-women.)

“This is really important because there have been very limited drug options for Alzheimer’s disease for 20 years and there is an urgent need for new treatments,” said Dr Rasha Saleh from UEA’s Medical School. “The effects of HRT in this observation study, if confirmed in an intervention trial, would equate to a brain age that is several years younger.”

A brain age “several years younger” is an attractive idea for those of us at risk. My mum Ella Muir died of Alzheimer’s eight years ago, and I know how much that illness affects not only the patient, but family and friends around them. The fact that previously there was no real cure, but just a few drugs which delayed but did not prevent the disease, left many daughters-of-Alzheimer’s like me utterly disheartened.

It was only when I started researching my book Everything You Need to Know About the Menopause (but were too afraid to ask) that I was excited to come across research, much of it in America, that showed the positive effects of HRT. I wrote a chapter on it. Women who topped up their hormones were less likely to have a build-up of amyloid plaques in their brains, which are often a precursor to Alzheimer’s. But long-term major studies are rare and expensive – that’s 20 or 30 years of research funding, and women’s health always seems to get left behind.

Yet two thirds of Alzheimer’s sufferers are women, and the disease tends to appear post-menopause –  women who go into early menopause in say their twenties or thirties are also more likely to get early-onset Alzheimer’s – unless they use HRT. The evidence was fascinating. I read all the academic papers – and even interviewed a Professor Karyn Frick in Wisconsin who discovered that mice whose ovaries had been blocked were more likely to get lost in a maze. Once she gave them their estrogen back, they found their way out.

What’s true of mice is true of women in this case, particularly those undergoing hysterectomy and oophorectomy. Dr Roberta Diaz Brinton of Arizona University told me: “Women who have had their ovaries removed before natural menopause show a deficit in short-term memory, long-term memory and logical reasoning. There’s an increased risk of cognitive impairment. The more estrogen a woman is exposed to in her lifetime, the better her brain fares.”

Dr Brinton says the “prodromal stage” or early signs of Alzheimer’s can be spotted in perimenopause, and for many women hormone replacement can help. She studied the health insurance records of almost 400,000 American women over 45 for ten years. Even women using the older oral combined HRT showed a 42 per reduced risk of neuro-degenerative diseases like Alzheimer’s and Parkinson’s Disease, but women on body-identical transdermal estrogen had a 73 per cent reduction in dementia compared to women not using HRT. The longer women stayed on HRT, the better the results. (Here’s the paper: https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/trc2.12174)

I also interviewed Dr Lisa Mosconi, author of The XX Brain who is the Director of the Women’s Brain Initiative and Director of the Alzheimer’s Prevention Clinic. She’s brilliant on the effect of estrogen on the brain, and the other ways apart from hormones that we can protect our brains: exercising every day, and eating a Mediterranean diet with plenty of vegetables and oily fish, and making sure you get enough Vitamin D. The Alzheimer’s Society says taking exercise can reduce your risk of dementia by 30 per cent.

We don’t yet know enough about the effect of testosterone (also a female hormone which gets low in menopause) on women’s brains, although we know that lower testosterone levels are associated with Alzheimer’s risk in men (Here’s the research: https://alzjournals.onlinelibrary.wiley.com/doi/10.1002/alz.12529).

Women deserve to know more about their risk – and the potential solutions. I had tea a few months ago with Dr Susan Kohlhaas, director of research at Alzheimer’s Research UK, and she is keen to see more research in this area. Me too, but for now, I’m very glad to be taking HRT – estrogen, testosterone and progesterone. I only wish I’d known about this earlier.

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