When I am retouching someone I can tell if they drink, smoke, and even if they are not eating right.
At about 28 a girls face, skin, and teeth start to show signs of aging and discoloration.
If they don't smoke or drink they can still look like they are still 21, if they do they look more like 33-ish. And the aging scale moves up from there.
Drinking and smoking dramatically speed up the aging process on the outside and most likely on the inside too.
• If you want to stay looking young. DON'T drink or smoke (legal or illegal). If you must try keeping it to a minimum (2-3 times a month).
• Exercise will not only keep you in shape, but it also gives a healthy glow to the skin.