A common drug endorsed by celebrities and used by millions could increase the risk of Alzheimer’s, British researchers have found
Research shows that a quarter of the millions of British women receiving conventional menopause treatment are at increased risk of developing Alzheimer’s disease.
Hormone replacement therapy (HRT), which uses synthetic versions of female sex hormones such as estrogen to replace levels lost in mid-life, has soared in popularity in recent years – now used by 2.6 million women.
Experts say the rising demand is partly due to celebrities like Davina McCall touting its benefits, claiming the drug does everything from boosting sex drive to sharpening memory.
But now scientists from Liverpool’s John Moores University have found that women with a certain genetic trait who use HRT have 60 percent higher levels of a molecule linked to Alzheimer’s disease, compared to genetically vulnerable women who don’t take the treatment.
The gene is called APOE e4 and is relatively common, found in about one in four people.
Previous research has shown that people with one copy of the gene have a double or triple chance of developing Alzheimer’s disease, although this can increase by a factor of ten for people with two copies in their genetic makeup.
Alzheimer’s disease is the leading cause of dementia – a memory-robbing disorder that robs people of their independence and is becoming increasingly common in Britain.
The authors of the new study said that their research, while still in its early stages, could have implications for deciding which women use HRT in the future.
Dr. Davide Bruno, an expert in neuropsychology who led the study, said: If our results are confirmed, they would warn against HRT use in women at increased risk of Alzheimer’s disease due to genetic susceptibility.
Davina MCCall is credited with inspiring thousands of women to try HRT after documenting her own experiences with menopause, dubbed the ‘Davina effect’.
The latest NHS data shows that a record 2.6 million women in England used HRT last year, a 12 per cent increase on the 2.3 million last year and double the figure for 2018/19
‘There is still much we do not know, but it may be prudent to test women for the presence of the APOE e4 variant before administering HRT, at least until more knowledge is gained on this issue.’
In the study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, experts analyzed samples of cerebrospinal fluid, the fluid that protects the brain and spine, from 136 women.
These women, who were on average 66 years old, had no cognitive problems at the time the samples were collected.
Scientists looked for a natural substance known to be a precursor to the brain plaques and tangles associated with Alzheimer’s disease.
They compared the results between women who used or did not use HRT, and between women with the APOE e4 variant and women without HRT.
Women taking HRT without the APOE e4 variant and women with a gene but not on HRT had similar levels of this molecule.
But in women who combined HRT and the APOE e4 variant, levels of this molecule were more than 60 percent higher than baseline.
It is still not clear exactly how HRT can lead to an increased risk of dementia.
Previous research on this topic has produced mixed results. Some studies, involving more than 400,000 women, found that HRT reduced the risk of dementia.
However, other studies among 50,000 women showed the opposite.
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss
Around 900,000 Britons are currently thought to suffer from memory theft disorder. But scientists at University College London estimate that this number will rise to 1.7 million within 20 years as people live longer. It represents an increase of 40 percent compared to the previous forecast in 2017
Adding to the confusion is that estrogen is considered good for brain health. Its absence explains why “brain fog” is a symptom of menopause.
Therefore, experts do not yet understand why HRT, which replaces this lost estrogen, would increase the risk of Alzheimer’s in some people.
But Dr. Bruno said one theory was that the hormone could cause further damage to cells in the brain that are already not functioning properly.
“We think this could be a scenario where estrogen exposure could benefit healthy neurons, but estrogen, in contrast, could worsen damage to ‘sick’ neurons,” he said.
The Alzheimer’s Society says the evidence linking HRT to the risk of dementia is mixed.
The organization says research in this area is clouded by important differences in studies, for example the different ages of the women participating.
In addition, the form of HRT taken – oral, topical or pessary – varies between studies, and it is thought that the type of medication may have a different effect on the risk of dementia.
The latest NHS data shows that a record 2.6 million women in England used HRT last year – a 12 per cent increase on the 2.3 million last year and double the figure for 2018/2019.
Recent analysis by the Alzheimer’s Society estimates that the total annual cost of dementia to Britain is £42 billion per year, with families bearing the brunt.
An aging population means these costs – including the lost income of unpaid caregivers – are expected to rise to £90 billion over the next fifteen years.
It is thought that around 944,000 people in Britain are living with dementia, while in the US the figure is around 7 million.
Alzheimer’s disease affects about six in ten people with dementia.
Memory problems, thinking and reasoning problems, and language problems are common early symptoms of the condition, which then worsen over time.
The analysis by Alzheimer’s Research UK found that 74,261 people died from dementia in 2022, up from 69,178 a year earlier, making it the country’s biggest killer.