While too much estrogen can cause reproductive issues, past research indicates that the risk of cardiac and stroke death increases in the first year after stopping hormone therapy.
Experts say this suggests the crucial role hormones play in heart health.
According to a new study, published today in the journal Neurology, people with longer exposure to estrogen may have a lower risk of stroke, which includes both ischemic stroke and intracerebral hemorrhage.
An ischemic stroke occurs when blood flow to the brain is blocked. An intracerebral hemorrhage, on the other hand, is caused by the rupture of a blood vessel in the brain, which leads to internal bleeding.
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What researchers discovered in estrogen study
For the study, researchers examined nearly 123,000 postmenopausal female participants without a previous history of stroke, collecting data on medical history, lifestyle, and reproductive health information.
The participants were separated into four groups based on their reproductive life span and the number of years from their first period to menopause.
The researchers reported that the female participants with the longest reproductive life span had a 5% lower risk of ischemic stroke and a 13% lower risk of intracerebral hemorrhage compared to women with the shortest reproductive life span.
“Our study suggests that higher estrogen levels due to a number of reproductive factors, including a longer reproductive life span and using hormone therapy or contraceptives, are linked to a lower risk of ischemic stroke and intracerebral hemorrhage,” said Peige Song, Ph.D., a study author and researcher at the Zhejiang University School of Medicine in Hangzhou, China, in a news release. “These findings might help with new ideas for stroke prevention, such as considering screenings for people who have a short lifetime exposure to estrogen.”
Dr. Atif Zafar, the chief of the stroke program at St. Michael’s Hospital of the University of Toronto, said that although more research is needed, there does appear to be a connection.
“The long reproductive lifespan reduces the risk of stroke in women likely due to the cardioprotective benefits of endogenous estrogen hormone,” Zafar told Healthline. “I am using the word endogenous as we do not want people to start supplementing themselves with estrogen until there is more research in the area.”
“Although more research is being done in this area,” he added. “I personally believe there is something in the natural (endogenous) estrogen (probably along with progesterone) that provides protection against stroke.”