Alzheimer's risk may be 35% lower with common menopause treatment, study finds

August 15, 2026 - 01:16

A new study from Stanford University suggests that women who use estrogen-only menopausal hormone therapy may have a significantly lower chance of developing Alzheimer's disease. The research, published in a leading medical journal, found that this common treatment was linked to a 35% reduction in Alzheimer's-related brain changes and a 39% lower risk of being diagnosed with dementia.

The study looked at health records from thousands of women over several decades. Researchers focused on those who took estrogen alone, without progestin, typically after a hysterectomy. The protective effect appeared strongest in women who started the therapy within five years of entering menopause. This timing seems to matter, as the brain may be more responsive to estrogen during that early transition period.

Lead researchers noted that the findings challenge some earlier concerns about hormone therapy and brain health. Previous studies had raised alarms about combined treatments, but this analysis separates the effects of estrogen-only options. The team emphasized that these results are observational, meaning they show a strong association but do not prove cause and effect.

Still, the data offers a hopeful direction. With millions of women going through menopause each year, understanding how standard treatments might influence long-term cognitive health is critical. The authors call for more clinical trials to confirm the link and to explore which women might benefit most. For now, they advise women to discuss their individual risk factors and treatment options with their doctors, rather than making changes based on this single study alone.