Dr Louise Newson looks at a new study adding to growing evidence of the role of hormone treatment in women’s long-term brain health

For far too long, many doctors and researchers have talked about hormone treatments (HRT) primarily in terms of improving menopausal symptoms. Low mood, brain fog, hot flushes, night sweats, poor sleep, and vaginal and urinary symptoms are all common symptoms that women seek treatment for.

However, we have known for many decades that women who take hormone treatments have a lower risk of future diseases – including heart disease, osteoporosis, diabetes and also dementia. Yet many clinicians choose to ignore the health benefits of taking hormone treatments which is harming millions of women.

There has been increasing confusion over recent years about the reduced risk of dementia in women who take hormone treatments due to these studies combining bioidentical hormone treatments with synthetic hormone treatments in their anyalses. The synthetic hormone treatments, especially progestogens like medroxyprogesterone acetate, work to block estradiol (the most beneficial form of estrogen) working in the brain – so there is no surprise they have not shown to be beneficial at reducing dementia risk.

A major new study suggests that hormone treatment is associated with a lower risk of dementia, particularly for certain groups of women.

Researchers from the University of East Anglia and the University of Exeter analysed health data from more than 183,000 menopausal women in the UK Biobank. They followed the women for an average of more than 13 years, during which almost 4,000 cases of dementia were identified.

Women prescribed hormone treatment for at least one year had a 10% lower risk of developing dementia than women who had never used it. The association was even stronger for Alzheimer’s disease, the most common form of dementia, with women using hormone treatment having a 16% lower risk.

This is a large study, with a long follow-up period, and that makes the findings worthy of attention.

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Surgical and early menopause

Perhaps even more interesting, however, is what happened when the researchers looked more closely at different groups of women.

The strongest reduction in dementia risk was seen in women who had experienced a surgical menopause. In this group, hormone treatment was associated with a very impressive 26% lower risk of developing dementia.

Women who had lower lifetime estrogen levels – for example, because they started their periods later or became menopausal earlier – also appeared to have a greater benefit with taking hormone treatment to reduce dementia risk.

The researchers also found stronger associations among women with the APOE4 gene variant (which is an important genetic risk factor for Alzheimer’s disease) and a lower risk of developing dementia,.

The findings also suggest that timing matters, with the association with lower dementia risk strongest among women who started hormone treatment between the ages of 46 and 56.

Why does this matter?

As a hormone specialist, I passionately believe this is a crucial area of research because I see firsthand the impact of menopause on women’s brains every day in my clinic.

Women frequently describe changes in their memory, concentration, word-finding and ability to think clearly in perimenopause and menopause. This affects their careers, relationships and wider self-esteem, with many women telling me that they no longer feel like themselves. Many women worry they have early dementia when then come to our clinic. We find that memory often really improves when women are prescribed hormone treatments – progesterone, estradiol and testosterone.

We know that hormone receptors are found in every cell in the brain, and these three hormones are also made in the brain. They have important effects on areas involved in memory, learning and other cognitive functions.

This latest study adds to a growing body of evidence about the roles of hormone treatments to improve brain health.

In my clinic, we hear all the time about memory improvements in our patients who take hormone treatments. A recent review found that 92% of new patients reported memory problems at their first consultation, and around half of them reported better memory at their next appointment, after taking hormone treatments for three months. Of those who rated their memory problems as moderate or severe at the start, 52% had improved to mild or no problems. Among women whose memory problems were severe, those taking testosterone were somewhat more likely to have improved to mild or no problems by their next questionnaire: 41% compared with 36%.

The importance of individualised care

One of the key takeaways from this study for me is that, when it comes to menopause, every woman’s experience is different and hormone treatments should be considered more often than they currently are.

The findings suggest that factors such as when a woman becomes menopausal, levels of estrogen through her lifetime, genetic factors and the age at which hormone treatment is started may all influence the relationship between hormone treatment and dementia.

The bottom line

This study found an association between hormone treatment use and a lower risk of dementia, particularly among certain groups of women.

It is important, however, to recognise that this was an observational study and did not assess the different types of hormone treatments, nor did it involve testosterone. Even so, I see this study as another important piece of the evidence puzzle.

Treatment conversation should not stop at symptom relief. All clinicians need to consider the health benefits of taking hormone treatments.

Key questions

This study gives us another reason to keep asking important questions about the relationship between our hormones, our brains and our long-term health.

We need more research to understand exactly when hormone treatment might be most beneficial, which women are the most beneficial, and how individual factors can influence outcomes.

Ultimately, we should be moving towards more personalised hormone treatments – something that I believe is essential. After treating thousands of women, I know that there is no single experience by women and treatment is not one size fits all.

For now, the message is an encouraging one: the evidence around hormone treatment and brain health is continuing to grow, and this large new study gives us another important reason to pay attention.

Read the full study, published in the journal Alzheimer's and Dementia, here.