Due to the recent rapid increase in the number of elderly people in the world, health management and maintenance in elderly people have become important issues. Centenaria, who are older than 100 years, tend to stay independent in their daily life with maintenance of cognitive function until the later stage of their life compared with elderly people who die earlier. In this review, we summarize the characteristics of centenarians, the genetic risk and protective factors for longevity, and intersections between research on centenarians and dementia research.