But not all people of the same age are really the same amount of 'old'. It seems likely that you get unhealthy faster, which causes your earlier death. It'd surprise me if it were closer to a symptomless clock that just killed you a bit earlier.

The distinction between sidereal years lived and 'biological age' (as well as mental age and such) deserve to be made more often. When people ask "but why would anyone want to live to be 1000 years old?", the answer might be "to play football!"