Permanent Effects of Lifting?

I was going through Ian King’s Out of Kilter series to run across this. “As a long term user of high external loading, even with the best care I can assure you that your joints will show black under an MRI! They take a pounding. After ten to twenty years of heavy lifting, that’s a likely outcome, so don’t make it any worse! Be smart and avoid major shoulder issues!”

It can be found in the 2nd paragraph here: http://www.t-mag.com/nation_articles/292kilt2.html

There’s also that sort of feeling obtained from this artice: http://elitefts.com/documents/throw_away_the_key.htm

Can one participate in such activities as lifting (or any sport really) and not destroy the bodies joints prematurely? The two articles above suggest that but provide no real evidence as to how such injuries occur and if they are really meaningful. Also, towards the end of the EliteFTS article the doctor is quoted as saying the author is too old to regenerate his joints. How old is too old? Is this information accurate?