FRIDAY, Nov. 22, 2024 (HealthDay News) -- Four years of hormone replacement therapy to help women deal with menopausal symptoms causes no harm to the brain, even over the long term, new research shows.

"In the present study, approximately 10 years after 48 months of early menopausal therapy... the cognitive performance of women randomized to [hormone replacement therapy] did not differ from those randomized to placebo," concluded a team led by Carey Gleason, of the University of Wisconsin-Madison.

Her team published its findings Nov. 21 in the journal PLOS Medicine.

For decades, millions of women took supplemental forms of estrogen long-term to help curb hot flashes and other menopausal symptoms. Then in 2002, results from the Women's Health Initiative study linked hormone replacement therapy (HRT) to an increased risk of blood clots, stroke, breast cancer and heart disease.

That caused a drastic decline in the use of HRT, but in recent years a more nuanced view of the risks and benefits of the treatment have emerged, with some women only taking HRT for a few years around the time of menopause.

Would this shorter course of HRT harm the brain?

Four years after stopping four years of HRT, an investigation called the Kronos Early Estrogen Prevention Study had already detected no declines in thinking or memory among users at that point in time. Kronos involved 727 women around the age of menopause, all of whom were in good cardiovascular health.

The newly published report looked at Kronos findings for 275 of those women, all of who were tested a full 10 years after they'd wrapped up their four years of hormonal therapy.

Again, the result was clear: "Menopausal hormone therapy was not associated with cognitive benefits nor does menopausal hormone therapy prevent cognitive decline," Gleason and team concluded.

That means that while HRT does no harm to the brain, it should not also be seen as a means of boosting a woman's neurological health as she ages, the researchers said.

“For women in menopause and the health care providers caring for them, getting direct, clear and evidence-based information about menopausal hormone therapy is challenging. And they need data to guide their decisions," Gleason's team wrote.

Women in the study received various forms of hormonal supplements (Premarin, Climara or Prometrium), given in pill or patch form, or placebo pills or patches.

More research into HRT's effect on brain health should be done, Gleason's group said.

"These findings highlight the need for further research to explore other potential long-term health outcomes associated with menopausal hormone therapy, beyond cognitive performance," they wrote. "Future studies could focus on areas such as mood and Alzheimer’s disease biomarkers."

More information

Find out more about the history of HRT research at the American College of Obstetricians and Gynecologists.

SOURCE: PLOS journals, news release, Nov. 21, 2024