HRT could help ward off dementia – but only if women take it when their menopause begins

Hormone replacement therapy may reduce the risk of dementia in women with early menopause — but only if they start treatment quickly, a study suggests.

Women make up about two-thirds of people with Alzheimer’s disease, with early menopause linked to an increased risk of the disease.

Now a study claims that those who are prescribed HRT from the onset of symptoms are not at greater risk.

But women who started treatment several years later — which helps control menopausal symptoms — had higher levels of two key proteins involved in dementia, beta-amyloid and tau.

Experts said it was not yet clear how menopause and hormone therapy affected the brain, and further research is needed.

In the most recent study, researchers from Mass General Brigham, Boston, USA, used brain imaging to study how the presence of two proteins involved in Alzheimer’s disease are related to age at menopause and HRT use.

They studied scans of 292 cognitively healthy adults to determine levels of amyloid and tau in seven brain regions.

They found that women had more tau compared to men of the same age, especially in cases where they also had elevated beta-amyloid.

Tau levels were high in the brain regions close to the brain’s memory center and areas known to be involved in the progression of Alzheimer’s disease.

The association between abnormal levels of the proteins was stronger in women with an earlier onset of menopause, defined as younger than age 45, than in women in general.

Since many women experiencing premature menopause often use HRT, researchers wanted to investigate whether its use was related to the two proteins.

Starting therapy late — five years or more after the onset of menopause — was associated with higher levels of beta-amyloid and tau, according to the findings in Jama Neurology.

Rachel Buckley, from Massachusetts General Hospital, said: ‘We found that the highest levels of tau, a protein involved in Alzheimer’s disease, were only observed in hormone therapy users who reported a long delay between the age of onset of menopause and the start of hormone therapy. .

“The idea that tau deposition may underlie the link between late hormone therapy intervention and dementia in Alzheimer’s disease was a huge find, something that had not been seen before.”

Evidence on HRT’s role in dementia has so far proved inconclusive, and research suggests it may have both protective and potentially harmful effects.

In January, a study by researchers at the University of East Anglia suggested that HRT may help prevent Alzheimer’s disease in women who carry the APOE4 gene, putting them at increased risk.

That suggested that HRT was most effective during perimenopause, where symptoms build up for months or years before periods actually stop.

Alzheimer’s Research UK said larger studies were needed to help understand the link between HRT and changes in the brain.

The charity pointed to conflicting previous studies, some of which highlighted the potential cognitive benefits of HRT, while others pointed to an increased risk of memory and thinking problems.

Dr. Sara Imarisio, lead researcher, said: ‘While this study adds valuable new data to this topic, we still cannot point to a definitive link between hormone therapy and Alzheimer’s disease or dementia.

“It is important that people are empowered with evidence-based advice that helps them make informed decisions about their health. But there is much more to understand about how menopause and HRT affect dementia risk.

“We need to see larger studies and controlled clinical trials to better understand this complex area of ​​research and understand conflicting findings that have emerged in recent years.”