Do the bones age faster than the mind?

It is bones vs mind for quite a few. Now what gets older fast is the issue. Weakness with passage of time in both is a given-gradual and inevitable. Can we have a technological paraphernalia that is able to quantify the strength quotient in both?
I have been around quite a few oldies who are suffering from osteo-arthritis and still have a very nimble mind. I wonder if old age has caught up with them just to decide how much sorry shall I feel for them. It goes without saying that on some other moments someone else will be contemplating a similar conundrum for me.
However, when I perceive the mental alacrity of these oldies I wish I could have returned into the fold similarly.