Science to'stop age clock at 50'

Centenarians with the bodies of 50-year-old will one day be a realistic possibility, say scientists.I think that's great! In Japan, aging population is growing rapidly in Japan so that if these people can have bodies of 50-year-old they they can work as much as they want to. Well, I guess there are not much people want to work though...
If I were over 50 years old, I definetly do not want to work.