Woman with pimple (Peter Dazeley | Getty Images)

“The correlation between diet and acne is controversial, but there is a good body of evidence supporting a relationship between the two,” says Joshua Zeichner, MD, Director of Cosmetic and Clinical Research and an Assistant Professor in the Department of Dermatology at Mt. Sinai Medical Center in New York City.

The research suggests that diets that rank high on the glycemic scale (meaning they’re rich in sugary and starchy foods) can raise insulin levels. And that can eventually affect the skin in ways that can lead to pimples. Another potential culprit is cow’s milk. “Cow’s milk, especially skim milk, is high in sugars and growth factors that may also stimulate the oil glands to go into overdrive and lead to pimples,” explains Zeichner.

His advice: adopt a low glycemic diet and switch to cow’s milk substitutes and see what happens. “But if you change your diet and you’re still breaking out, go see your dermatologist,” he suggests. “There are great medications that can effectively treat your pimples and help prevent permanent scarring.”