I've heard that 80 is the magic number when your life gets harder due to old age. The body starts breaking down much faster after that. Does anyone have any sou

I've heard that 80 is the magic number when your life gets harder due to old age. The body starts breaking down much faster after that. Does anyone have any sources to back that up? I know that people I've known seem to have more health problems as they get into their 80's. Any way you look at it, life is short.