I think it's a big one, too. Seriously: smokers age hard and the more you smoke, the faster it happens. It's a crapload of oxidative stress combined with someti

I think it's a big one, too. Seriously: smokers age hard and the more you smoke, the faster it happens. It's a crapload of oxidative stress combined with sometimes serious end-organ vascular consequences (to say nothing of the carcinogenic effects). That said, I imagine it's also a marker for other types of behaviours likely to age people quicker.