There is increasing evidence of a cause-and-effect link between dairy consumption and acne in some individuals. Research is ongoing. Skim milk, whole milk and soft cheeses are more likely to trigger breakouts than other forms of dairy. A dairy-free diet may be beneficial for acne in those susceptible to milk products.

That means that drinking a glass of milk, even several glasses of milk every day, isn't going to cause someone with otherwise clear skin to suddenly start breaking out in pimples. The research shows that drinking milk may make acne worse for people who are already breakout-prone.