Researchers have suggested that hormone replacement therapy (HRT) may help prevent it in women at risk of developing Alzheimer’s disease.
One team said the use of HRT, which helps control menopausal symptoms, is associated with better memory, cognitive function and larger brain volumes in women who carry a gene called APOE4.
Around a quarter of women in the UK are thought to carry the APOE4 gene, and Alzheimer’s is more common in women than men.
APOE4 is the strongest risk factor gene for Alzheimer’s disease, but inheriting APOE4 doesn’t necessarily mean a person will develop the condition.
In a new study, researchers found that HRT is most commonly given during perimenopause—where symptoms build up months or years before menses actually stop—and can lead to brains that look several years younger.
Professor Anne-Marie Minihane from UEA’s Norwich Medical School, who led the study with Professor Craig Ritchie of the University of Edinburgh, said: “We know that 25% of women in the UK are carriers of the APOE4 gene, and almost two-thirds have Alzheimer’s patients. woman.
“In addition to living longer, the higher incidence in women is thought to be due to the effects of menopause and the greater impact of the genetic risk factor APOE4 in women.
“We wanted to find out if HRT could prevent cognitive decline in at-risk APOE4 carriers.”
The experts analyzed data from 1,178 women involved in the European Prevent Alzheimer’s Dementia initiative, which was set up to examine participants’ brain health over time.
Covering 10 countries, the project followed the brains of a total of 1,906 people over the age of 50 who did not have dementia at the start of the study.
For the latest research, experts looked at the results of cognitive tests and brain volumes recorded by MRI scans.
The results showed that HRT-using APOE4 carriers had better cognition and higher brain volumes than non-HRT-using and non-APOE4 carriers.
Dr Rasha Saleh from UEA’s Norwich Medical School said: “We found that the use of HRT is associated with better memory and larger brain volumes among at-risk APOE4 gene carriers.
The associations were particularly evident when HRT was introduced early, that is, during the transition to menopause, known as perimenopause.
“This is really important because there have been very limited drug options for Alzheimer’s disease for 20 years and new treatments are urgently needed.
“The effects of HRT in this observational study, if confirmed in an intervention trial, would mean brain age would be several years younger.”
Prof Minihane said the team did not look at cases of dementia, but cognitive performance and low brain volumes predict future dementia risk.
Prof Michael Hornberger, of the UEA Norwich Medical School, said: “It is too early to be sure that HRT reduces the risk of dementia in women, but our results highlight the potential importance of HRT and personalized medicine in reducing the risk of Alzheimer’s.
“The next phase of this research will be to conduct an intervention trial to confirm the impact of starting HRT early on cognition and brain health. It will also be important to analyze which types of HRT are most beneficial.”
Prof Craig Ritchie of the University of Edinburgh said the study, which was shared only with the PA news agency, “supports the idea that HRT has tangible benefits”.
“It underlines the need to question the many assumptions about early Alzheimer’s disease and its treatment, especially when it comes to women’s brain health,” she said.
Dr Sara Imarisio, head of strategic initiatives at Alzheimer’s Research UK, said: “Based on analysis of data from women who participated in a large study that has followed around 2,000 people since 2015, these findings are encouraging but need to be confirmed in further studies.” .
“They provide evidence that HRT may have some cognitive benefits, particularly in women who carry the Alzheimer’s risk gene APOE4.
“The next step is to explore this in more detail. More importantly, this study did not measure whether women develop dementia.
“Therefore, their findings need to be confirmed by research that primarily directly tests whether giving HRT affects women’s cognitive abilities and changes in their brains, particularly carriers of the APOE4 gene.
“This will then help pave the way for finding possible interventions, for example clinical trials to see if it can eventually prevent dementia and help understand why dementia disproportionately affects women in the UK.
“Studies like this help piece together how various risk factors for dementia, such as our age, genetics, and menopause, may combine to influence a person’s risk of developing diseases such as Alzheimer’s.”
Alzheimer’s Association research director Dr. Richard Oakley said: “Studies like these are important because they imply a link between HRT and changes in the brain.
“We need more studies at a larger scale to better understand this link.”
The study was published in the journal Alzheimer’s Research & Therapy.