A comprehensive review led by researchers from University College London has found no evidence that menopause hormone therapy impacts the risk of dementia in post-menopausal women. This significant study, supported by the University of Exeter and commissioned by the World Health Organisation (WHO), was published in The Lancet Healthy Longevity and provides clarity on a contentious topic.
The findings reinforce current clinical guidance that menopause hormone therapy, also known as hormone replacement therapy (HRT), should be considered based on its perceived benefits and risks rather than for dementia prevention. Professor Chris Fox from the University of Exeter Medical School commented,
“The role of menopause hormone treatment and relationship to dementia is a worry for many women. But our state-of-the-art review indicates there is no evidence that menopause hormone treatment reduces or increases the risk of dementia.”
Comprehensive Analysis of Existing Research
This new systematic review and meta-analysis is the most thorough synthesis of evidence regarding menopause hormone therapy and dementia risk to date, involving data from over one million participants. The study’s publication follows a recent decision by the U.S. Food and Drug Administration (FDA) to remove ‘black box’ warnings on menopause hormone therapy products, which previously included claims of increased dementia risk.
Lead author Melissa Melville, a PhD student at UCL Psychology & Language Sciences, emphasized the importance of this research, stating,
“Across the globe, dementia disproportionately affects women, even after accounting for women’s longer lifespans, so there’s a pressing need to understand what might be driving that risk, and to identify ways to reduce women’s risk of dementia.”
Insights from the Study
The international research team, with members from the UK, Ireland, Switzerland, Australia, and China, compiled the best available evidence on potential links between menopause hormone therapy and dementia risk. This included data from one randomized controlled trial and nine observational studies, encompassing a total of 1,016,055 participants.
The analysis revealed no significant association between menopause hormone therapy and the risk of dementia or mild cognitive impairment. Even when examining subgroups based on timing, duration, and type of therapy, no significant effects were found. Furthermore, the study found no evidence that menopause hormone therapy affected dementia risk after early menopause.
Limitations and Calls for Further Research
Despite these findings, the researchers caution that their conclusions are limited by the scarcity of relevant randomized controlled trials and the relatively low certainty of much of the existing evidence. They highlight the need for high-quality, long-term research, especially in women from ethnic minority backgrounds or those with early menopause, premature ovarian insufficiency, or mild cognitive impairment.
Senior author Professor Aimee Spector from UCL Psychology & Language Sciences noted,
“Currently, the World Health Organisation provides no guidance on menopause hormone therapy and cognitive outcomes, leaving a critical gap for clinicians and policymakers. To cut through the noise, we reviewed the most rigorous research there is on the subject and found that menopause hormone therapy does not appear to impact dementia risk either positively or negatively.”
Future Implications and Guidelines
This review is expected to inform upcoming WHO guidelines on reducing the risk of cognitive decline and dementia, set to be released in 2026. However, the researchers stress that more high-quality, long-term studies are essential to fully understand the long-term impacts of menopause hormone therapy.
As the debate over menopause hormone therapy continues, this study provides a crucial piece of the puzzle, helping women and healthcare providers make informed decisions based on the most current and comprehensive evidence available.
