Drugs
Sun damage
Extreme dieting (bulking and cutting)
Smoking
in that order
You beat me to it. Smoking and sun damage being at the top of the list. When the skin thins and then fills with water, and when the body shrinks and bloats (over and over) its elasticity says "adios"
I would dare say smoking and recreational dope along with sun damage makes the perfect recipe for premature aging. Not to mention the fact that every day, he is, in fact, getting....
Older.