Dementia Risks Vary by Menopause Hormone Therapy Timing, Study Shows

A large study published in Alzheimer's & Dementia reveals that the timing of hormone replacement therapy (HRT) initiation significantly impacts dementia risk in postmenopausal women. Led by Anne-Marie Minihane from the University of East Anglia, the research analyzed data from nearly 185,000 women in the U.K. Biobank followed for an average of 13.3 years.

Starting HRT between ages 46 and 56 proved most beneficial, reducing dementia risk by 23% compared to those who began later. The study found lower dementia risk for women who started HRT at ages 46-50 (HR 0.87), and even higher protection for those initiating therapy between 51-56 years (HR 0.77). These associations were most pronounced in women who experienced surgical menopause, carried the APOE4 gene variant, or had lower pre-existing estrogen levels.

The study adds to growing evidence suggesting HRT initiation during the menopause transition, when symptoms are more prominent, may be crucial for preserving brain health. It also highlights the importance of individual factors like surgical menopause and genetic predisposition in determining HRT's protective effects on dementia risk.