Health
Large study links early hormone therapy to lower dementia risk
Researchers found a modest 10% risk reduction in postmenopausal women who started treatment between ages 46 and 56, supporting the timing hypothesis.
The short version
- A new observational study of over 180,000 UK women suggests hormone replacement therapy (HRT) is associated with a 10% lower risk of dementia when initiated between ages 46 and 56.
- The findings contrast with earlier landmark research, such as the Women's Health Initiative study, which linked HRT in older women (average age 63) to higher health risks.
- Experts emphasize that while the findings support starting HRT early near the onset of menopause, the observational study lacks a placebo control group and requires further replication.
Key facts
- A UK study by researchers at the University of East Anglia and the University of Exeter analyzed over 180,000 postmenopausal women and found a modest 10% lower dementia risk for HRT users.[Business Insider]
- The study identified the greatest cognitive benefits for women who began HRT between the ages of 46 and 56.[Business Insider]
- The early 2000s Women's Health Initiative study associated HRT use in older women (average age 63) with increased risks of heart disease, stroke, breast cancer, and dementia, leading to US black box warnings in 2003.[Business Insider]
- The FDA removed black box warnings from HRT products in late 2025.[Business Insider]
What remains uncertain
- Because the UK study was observational and lacked a placebo-controlled group, experts note that additional research is required to confirm a causal relationship.[Business Insider]