Analysis of 876,805 Danish women followed for a median 14.3 years revealed that those using menopausal hormone therapy had an 11% reduction in all-cause mortality compared to non-users, with particularly strong protective effects against cardiovascular deaths. The large-scale registry study tracked women from age 45 through 2023, controlling for multiple confounding factors including income, education, and pre-existing conditions.
This finding challenges the prevailing narrative around hormone replacement therapy risks that emerged from the Women's Health Initiative two decades ago. While that landmark trial identified increased breast cancer and stroke risks, it may have obscured mortality benefits by focusing on older women who started therapy years after menopause onset. The Danish data suggests timing matters critically—women initiating therapy closer to natural menopause may experience net longevity benefits through cardiovascular protection that outweigh cancer risks. However, the observational design cannot definitively establish causation, and the predominantly white Danish population limits generalizability. The study reinforces emerging evidence for a "timing hypothesis" in hormone therapy, suggesting that personalized risk-benefit calculations should consider individual cardiovascular risk profiles alongside traditional contraindications.
