Women who go through the menopause develop early are more likely Alzheimer’s at a younger age, new research suggests.
Those who experience the hormonal change in their early 40s develop symptoms of the memory-robbing disease almost two years earlier than other patients.
Entering menopause around age 45 is associated with 15 percent more dementia-related brain damage than happening five years later.
Researchers from the University of California San Francisco explained that the sex hormone estrogen – which declines dramatically during menopause – is known to protect against cognitive decline.
In the publication JAMA Neurology, the experts suggest that the age at which a woman begins menopause could serve as an “early marker” of Alzheimer’s disease “long before cognitive changes become apparent.”
For the study, researchers analyzed data from more than 2,600 women in the US with an average age of 78 years.
About two-thirds of participants experienced a natural, age-related decline in hormones, while the rest underwent surgical menopause – caused by, for example, removing their ovaries.
The women announced the age at which they entered menopause (average 49 years) and underwent regular memory and thinking tests.
Research has suggested that women are more likely to develop dementia than men because they lose gray matter during menopause
Researchers also conducted brain scans on hundreds of participants to monitor changes over time.
Earlier menopause was associated with poorer cognitive outcomes, earlier onset of Alzheimer’s disease and faster brain shrinkage in later life.
Specifically, women who experienced natural menopause around age 45 developed 15 percent more age-related brain damage over a decade compared to those who started menopause at age 50, the researchers estimated.
The damage affected the white matter, which is responsible for transmitting messages between brain cells and is known to decline as dementia develops.
Overall, the researchers estimated that women who went through menopause 10 years earlier than the average age of 49 had about 1.8 fewer years without an Alzheimer’s diagnosis than those whose menopause occurred 10 years later.
Earlier menopause was also linked to a faster decline in episodic memory, the ability to remember events and experiences, as measured by annual cognitive tests.
Surgical menopause was more strongly linked to the risk of Alzheimer’s and memory loss, while earlier natural menopause was more strongly linked to signs of brain aging on scans.
The researchers suggested that this could be because when both ovaries are removed, hormone levels drop dramatically, rather than gradually over time.
Researchers believe estrogen helps protect the brain by supporting communication between brain cells, maintaining the protective covering around nerves and warding off inflammation.
However, experts emphasized that the findings do not mean that women who experience early menopause will inevitably develop Alzheimer’s disease.
But they added that those who enter menopause early should try to limit their risk.
It comes as the Daily Mail and the Alzheimer’s Society are working together in a drive to beat dementia, which claims 76,000 lives every year and is Britain’s biggest killer.
The Defeating Dementia campaign aims to raise awareness of the disease, in an effort to increase early diagnosis, stimulate research and improve care.
Michelle Dyson, chief executive of the Alzheimer’s Society, said women make up around two-thirds of the 982,000 people with dementia in Britain – of which Alzheimer’s is the most common form.
“And while we still don’t fully understand why they are more sensitive than men, it is thought that hormones may play a role,” she said.
‘There are steps women – and men – can take today to reduce their risk of dementia, including regular exercise, not smoking and reducing alcohol consumption.
‘If you are concerned about yourself or a loved one, the Alzheimer’s Society’s Dementia Symptoms Checklist is a useful first step in starting a conversation with your GP.’
Menopause usually occurs between the ages of 45 and 55 and is the time when sex hormone levels permanently drop and menstruation stops.
The most common symptoms are hot flashes, sleep problems, mood swings and vaginal dryness. It is believed that up to 80 percent of women suffer from these symptoms, while a quarter suffer from anxiety, brain fog and memory problems.
