HRT can help prevent dementia, but only if women take it when they start menopause

Hormone replacement therapy can 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 associated with an increased risk of the disease.

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

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

Experts said it is not yet clear how menopause and hormone therapy affect the brain, and more 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 was related to menopausal age and the use of HRT.

They examined 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 amyloid beta.

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

The association between abnormal protein levels was stronger in women with an earlier onset of menopause, defined as less than 45 years of age, than in women in general.

Because many women with premature menopause regularly use HRT, the researchers wanted to see if their 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 Jama Neurology’s findings.

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

“The idea that tau deposits may underlie the link between late intervention in hormone therapy and dementia in Alzheimer’s disease was a major finding, something that had never been seen before.”

The evidence for the role of HRT in dementia has so far proved inconclusive, and research suggests that it may have both protective and potentially harmful effects.

In January, a study by researchers at the University of East Anglia suggested that hormone replacement therapy could help prevent Alzheimer’s disease in women who carry the APOE4 gene, which can put them at greater risk.

This suggested that HRT was most effective during perimenopause, where symptoms build up for months or years before menstruation actually stops.

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

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

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

“It is important that people get evidence-based advice to help them make informed decisions about their health. But there is much more to understand about how menopause and HRT affect the risk of dementia.

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