Eh, I started riding centuries at age 13ish.
If anything, it helped with joint problems I have from being born with a club foot.
So not a study, but just a informed anecdote.
You won't find studies on CYCLING, because that is too small of a field of study, but you can find lots of studies on sports in general. They generally focus on injuries, which in sports like American football which happen more frequently than cycling. Heck, you expected to hit your head on EVERY play in football, not just in a crash!