Cycling and mixed-cycling modes showed a significantly lower risk of all-cause dementia in the group without APOE ε4 (HR, 0.74 [95% CI, 0.63-0.87]) compared with the group with APOE ε4 (HR, 0.88 [95% CI, 0.76-1.02]), suggesting that those without APOE ε4 derived greater benefits from active travel modes. This evidence concerns the gene APOE and dementia.