Alzheimer’s disease is more common in women due to a combination of longer life expectancy, sex-specific biological mechanisms, and genetic, hormonal, and lifestyle factors that increase risk and accelerate disease progression.
While women live longer than men and age is the greatest risk factor for Alzheimer’s disease, longevity alone does not fully explain the higher prevalence.
Sex-specific biological factors play a major role: The menopause transition, with its sharp decline in estrogen (especially 17β-estradiol), is associated with increased vulnerability to Alzheimer’s pathology, including earlier and greater accumulation of tau and amyloid-beta proteins in the brain.
Estrogen is thought to have neuroprotective effects, and its loss during menopause may accelerate neurodegeneration.
Genetic factors also contribute: The APOE-ε4 allele, the strongest known genetic risk factor for late-onset Alzheimer’s, confers a higher risk in women than men, particularly between ages 65 and 75.
Women with one copy of APOE-ε4 have a risk equivalent to men with two copies, and female carriers experience faster neurodegeneration and cognitive decline.
Depression and diabetes increase dementia risk more in women than men, and women are more susceptible to lifestyle-related risks such as midlife hypertension, dyslipidemia, and smoking.
Female-specific reproductive factors—such as early menopause, bilateral oophorectomy, hypertensive pregnancy disorders, and late initiation of hormone therapy, further elevate risk.