A major new study led by researchers at University College London (UCL) has found no evidence that menopause hormone therapy (HRT) increases or decreases the risk of dementia in post-menopausal women. The findings, commissioned by the World Health Organization (WHO) and published in The Lancet Healthy Longevity, provide clarity on a long-debated topic and reinforce current guidance that HRT should be used based on symptom management, not dementia prevention.
The systematic review and meta-analysis is the largest and most comprehensive study to date, analysing data from over 1 million participants. It included one randomised controlled trial and nine observational studies, examining potential links between menopause hormone therapy and dementia, including Alzheimer’s disease and other cognitive impairments.
Key Findings
- No significant association was found between menopause hormone therapy and dementia risk.
- Subgroup analyses, considering timing, duration, and type of HRT, still showed no effect on dementia risk.
- Early menopause and use of HRT did not alter dementia outcomes.
- Lead author Melissa Melville, a PhD student at UCL, highlighted the importance of the study:
“Menopause hormone therapy is widely used to manage menopausal symptoms, yet its impact on memory, cognition, and dementia risk has been debated. Conflicting research left women and clinicians unsure whether HRT might raise or reduce dementia risk. Our review shows no evidence for either effect.”
The study comes after the U.S. Food and Drug Administration (FDA) recently announced the removal of ‘black box’ warnings on HRT products, which had previously cited potential dementia risks. The FDA had also suggested a potential protective effect against Alzheimer’s, a claim not supported by the new review.
Expert Perspective
Senior author Professor Aimee Spector of UCL emphasized the importance of evidence-based guidance:
“Currently, the WHO provides no guidance on menopause hormone therapy and cognitive outcomes. This review confirms that HRT does not appear to affect dementia risk, positively or negatively, and will help inform the upcoming WHO guidelines on reducing cognitive decline and dementia risk, expected in 2026.”
The researchers note that while the review is comprehensive, evidence from high-quality randomised trials remains limited, especially for women from ethnic minority backgrounds, those with early menopause, premature ovarian insufficiency, or mild cognitive impairment. They call for long-term, rigorous studies to better understand the full impact of HRT on cognitive health.
