I think it all comes down to a combination of genetics, environment and work/life balance.
No one in my immediate family looks their age; we all look 10-15 years young.
I'm closing in on 55, yet still look like I can pass for someone in their forties.
I have a coworker who is a few years younger than me, yet looks a decade or more older, thanks to being almost completely Grey and drinking and smoking two-three packs a day.