A new study suggests that postmenopausal women who begin hormone replacement therapy (HRT) around the time of menopause may have a lower risk of developing dementia in later life. Researchers analysed UK Biobank data covering over 183,000 women and found HRT use was linked to roughly a 10% lower risk of all-cause dementia and a 16% lower risk of Alzheimer's disease over a 13-year period, with the strongest protective association seen in those who started treatment between ages 46 and 56. The findings add to ongoing debate about HRT's broader health effects, though experts caution the results are observational and cannot prove that hormone therapy directly prevents dementia.

The benefit was also notable among women who had undergone surgical menopause, while starting HRT after age 56 showed no association with reduced dementia risk. The study did not assess safety outcomes, dosages, or the type of hormone therapy used, and researchers noted that HRT users may differ from non-users in health, lifestyle or healthcare access, which could partly explain the results. Most participants were of European ancestry and relatively affluent, limiting how broadly the findings apply. Doctors quoted in the article stressed the study alone doesn't justify seeking HRT purely for dementia prevention, urging women with menopausal symptoms to discuss individual risks and benefits with their doctor, while researchers plan randomised controlled trials to further test the link.