The summary of an extensive review of all studies examining the relationship between diet and acne were published and sent a very clear message. While no other food group showed consistent link to acne, dairy did. The researchers are not sure whether this is due to the hormones in milk, milk protein or the effect of milk on insulin and IGF-1 (hormone-like substance) concentrations or whether it’s all these factors working together. However, dairy has been repeatedly shown to markedly aggravate acne.
Burris, J., Rietkerk, W., Woolf, K., 2013. Acne: The Role of Medical Nutrition Therapy. Journal of the Academy of Nutrition and Dietetics. 113 (3) 416-430.