Among the APOE-ε4 carriers, each 50 g/day higher total dairy intake was associated with 6% (95% CI: 2%, 10%) higher multivariable-adjusted risk of incident AD (P-interaction 0.007), each 50 g/day higher non-fermented dairy intake with 5% (95% CI 1%, 9%) higher risk (P-interaction 0.03), and each 50 g/day higher total milk intake with 5% (95% CI 1%, 9%) higher risk (P-interaction 0.03). Here, APOE is linked to Alzheimer disease.