Scientists are promising that centenarians with the bodies of 50-year-olds will one day be a realistic possibility.
(Half of babies now born in the UK will live to be 100, but our bodies are wearing out. So, Leeds University is spending £50m over five years looking at ways we can reach "50 active years after 50". They plan to provide pensioners with own-grown tissues and durable implants; new hips, knees and heart valves are the starting points, and eventually an upgrade of any body parts. They'll have to hurry up though, otherwise it will be too late for me.)