Well really it's not when do we stop growing and start dying, as we are constantly doing both, but rather I suppose when we reach the peak and become more one than the other.. Anyway, I still say 42 is said peak.
i love this painting! and i would say that the two are not mutually exclusive. once you begin living, you start dieing, and you never really stop growing, until sometime soon after death
and ah yes to answer the question, 'when do you stop growing and start dying'? well, we stop growing after puberty. as for the death, one could argue we are slowly dying as we age. but since there are cells constantly dying and new ones forming, we aren't really dying as such, because we are continuing to live. we start dying when some form of rapid degeneration begins to take place. i.e. we get cancer, heart problems, have some sort of trauma to vital organs etc etc. One could also argue that we start dying the minute we are born for the start of a life is the beginning of the end.
It happens when ( at this point try to envision several long dense paragraphs involving the production of telomerases - that I am preventing you from having to read) and that is how we think it works. I hope that this has been of help. (Grin)