[masraum]

My opinion: Genetics certainly don't hurt, but I think 90-95% of the end result is determined by how the person takes care of themselves. Have they stayed in shape (exercise) or sat on their butt? Did they get fat or stay thin (too thin seems to be bad too)? Did they eat well or stuff their face with McDonalds? Do they drink, smoke, party, do drugs often?

Smoking and drinking and doing drugs will age you at an accelerated pace.
Eating like crap and being heavy will age you.
Not staying in shape will often cause you to age.

I think mental outlook has something to do with it too. A combination of a positive outlook and thinking/feeling young. It seems like folks that give up.

I think there are folks that can be genetic outliers that can do whatever they want and still age well and other folks who will do everything right and still fall apart early.