Of the women studied, a whopping 72.9 percent of acne sufferers were smokers. Even more interesting, researchers found a positive correlation between the number of cigarettes smoked and the severity of comedonal acne. Just one more reason to ditch the cigarettes, especially considering all of the other ways that smoking harms your looks and health. Need help kicking the habit? Check out FitSugar's tips on quitting. Your lungs (and hair and skin) will thank you.