Jul 30, 2021

New research: How women’s hormone therapies could help reduce the risk of dementia

Women who take hormone therapies to treat the symptoms of menopause are up to 58% less likely to develop neurodegenerative diseases such as Alzheimer’s disease and dementia, new research has found.

A new study by the University of Arizona Health Sciences has found that women using hormone therapies were up to 58% less likely to develop neurodegenerative diseases, such as dementia.

The degree of risk varied depending on the type and application method of hormone therapy and how long the therapy was used.

The study found that women who took menopausal hormone therapy for six years or longer were 79% less likely to develop Alzheimer's disease and 77% less likely to develop any type of neurodegenerative disease.

“What is important about this study is that it advances the use of precision hormone therapies in the prevention of neurodegenerative disease, including Alzheimer’s,” said Roberta Diaz Brinton PhD, Director of the University of Arizona Center for Innovation in Brain Science and the senior author of the paper.

Hormone therapy is used to treat the symptoms of menopause, which can include hot flashes, night sweats, insomnia, weight gain and depression.

In the study, the researchers looked at the insurance claims of nearly 400,000 women aged 45 and older who were in menopause.

The researchers focused on the effects of hormone therapy medications on neurodegenerative diseases, and looked at the impacts of the type of hormone therapy, the route of administration (oral vs through the skin) and how long the therapy was taken.

They found that the natural steroids estradiol or progesterone reduced the risk of developing a neurodegenerative disease to a greater extent than synthetic hormones.

Hormone therapies taken orally resulted in a reduced risk for combined neurodegenerative diseases.

Hormone therapies administered through the skin reduced the risk of developing dementia.

The risk of developing neurodegenerative disease overall was reduced the most in patients 65 years or older.

Long-term therapy (longer than one year) had a greater protective effect on developing Alzheimer’s, Parkinson’s disease and dementia compared to short-term therapy (less than one year).

A press release from the university said the findings could lead to the development of medicines that could prevent neurodegenerative diseases.

"This reduction in risk for Alzheimer's disease, Parkinson's and dementia means these diseases share a common driver regulated by estrogen, and if there are common drivers, there can be common therapies," said Dr Brinton, who has researched neurodegenerative diseases and the ageing female brain for more than 25 years.”

“The key is that hormone therapy is not a treatment, but it’s keeping the brain and this whole system functioning, leading to prevention. It’s not reversing disease; it’s preventing disease by keeping the brain healthy.”

Given the global problems associated with ageing populations, neurodegenerative diseases associated with ageing are major public health issues.

Currently, there is no known cure for dementia, which affects nearly 500,000 people in Australia and 50 million worldwide.