Early menopause could increase risk of developing dementia, study finds

Women who enter the menopause before the age of 40 are more likely to develop dementia as they grow old, a new study suggests.

Researchers at the Shandong University in Jinan, China, analysed data on more than 150,000 women, finding that those who started the menopause before age 45 were 1.3 times more likely to develop early on-set dementia by their 65^th birthday.

Experts believe that being aware of this increased risk can help women take preventative steps against developing dementia, such as regularly exercising, not smoking or drinking, and working with doctors to monitor and assess their brain health as they age.

“Our study found that women who enter menopause very early were at greater risk of developing dementia later in life,” Wenting Hao, a PhD candidate at the university said.

“Being aware of this increased risk can help women practice strategies to prevent dementia and to work with their physicians to closely monitor their cognitive status as they age.”

Worldwide, more women are affected by dementia than men, however scientists are unsure why this is the case.

Dementia involves serious changes in the brain that impair a person’s ability to remember, make decisions and use language.

Alzheimer’s disease is the most common type of dementia, while the second most common is vascular dementia, which is the result of disruptions in blood flow to brain cells caused by strokes or plaque build-up in arteries supplying blood to the brain.

One of the main theories is to do with the hormone oestrogen, the production of which declines during menopause. While both both men and women produce oestrogen, it is the main female sex hormone and therefore women have more of it.

Men continue to produce testosterone throughout their lives, and this is converted to oestrogen inside their brain cells.

This means men in their old age have higher levels of oestrogen in their brain than women of the same age, experts at the Alzheimer’s Society explain.

Experts believe oestrogen may play a key role in protecting the brain from damage caused by Alzheimer's, but this protective effect is diminished when oestrogen levels decrease.

One previous study, carried out on rats, found that oestrogen helps increase the number of connections in a part of the brain called the hippocampus. The hippocampus is important for memory and certain types of learning.

People with Alzheimer’s have a build-up of amyloid-β and tau proteins in the brain, which are thought to damage brain cells.

Some research has pointed to oestrogen’s ability to protect the brain from Alzheimer’s by blocking the harmful effects of the amyloid-β protein.

According to the latest study, which looked at data of 153,291 women, the likelihood of women developing dementia was the same for all those over the age of 50.

Hao said dementia can be prevented. “There are a number of ways women who experience early menopause may be able to reduce their risk of dementia.

“This includes routine exercise, participation in leisure and educational activities, not smoking and not drinking alcohol, maintaining a healthy weight, getting enough vitamin D and, if recommended by their physician, possibly taking calcium supplements.”