For a select group, a new dementia prevention tool with incredibly effective results has been discovered. It comes in the form of a commonly-taken drug, and could be crucial for the health of women as they age.
Researchers from the University of East Anglia and the University of Exeter found a clear link between hormone replacement therapy (HRT) and a reduction in the risk of dementia. This was found during the largest study of its kind.
The researchers found that women who had used HRT had a 16% lower risk of developing Alzhemier’s in comparison to those who had never used it.
Of all the women examined, the greatest reduction occurred in those who had undergone surgical menopause, seeing a 26% lower risk of developing dementia compared with non-users of HRT.
“Dementia affects millions of people worldwide, with women making up almost two thirds of Alzheimer’s disease cases, the main form of dementia. As populations age, understanding how sex‑specific factors influence dementia risk is increasingly important,” said Prof Anne-Marie Minihane, one of the leads on the study.
“In addition to living longer, the reason behind the higher female prevalence is thought to be related to the effects of menopause on brain metabolism and the impact of the main genetic risk factor APOE4 being greater in women.”
Studying dementia risks
To find this connection, the research team analysed health data from the UK Biobank. They tracked 183,450 postmenopausal women over an average follow-up period of 13.3 years.
In that time, almost 4,000 cases of dementia were identified. The study looked at whether using HRT for at least one year was associated with the risk of developing dementia.
“We found that women who had used HRT were about 10% less likely to develop dementia, and 16% less likely to develop the Alzheimer’s disease form of dementia, than women who had never used it, said Minhane.
“But the protective association between HRT and dementia was not the same for all women.”
Who could benefit most from this treatment?
The HRT drug was especially effective in women who had undergone surgical menopause, such as having their ovaries removed. Women whose bodies naturally produced less oestrogen over their lives also seemed to get more help from HRT.
Equally, there was a link between HRT use and dementia risk reduction in women who carry the APO34 gene variant, a known risk factor for Alzheimer’s disease.
In line with this, there was an exact age range that saw the highest success rate. Those who started HRT between the ages of 46 and 56 experienced the greatest reduction in dementia risk.
“Our findings contribute to growing evidence that hormone therapy’s effects on brain health are complex and influenced by individual biological factors,” said Minihane.
“While HRT has long been prescribed primarily to relieve menopausal symptoms such as hot flushes and night sweats, this work suggests it may also play a role in long‑term cognitive health for some women.”
This research builds on an existing bank of studies that are making connections between HRT and women’s cognitive health as they age.
