Research studies have confirmed that frequency of milk and ice cream intake was positively associated with acne vulgaris occurrence. It has been shown that women, who consumed two or more servings of skimmed milk every day, were 22% more likely to suffer from severe acne and 44% more likely to develop cystic or nodular acne than those who consumed only one glass of skimmed milk a day.
Endocrine factors involved in acne may be affected by milk consumption because milk is an insulinotropic nutrient and has a high insulinemic index which would increase serum insulin and IGF-1 levels. There is increasing evidence in support of the interplay of growth hormone (GH), insulin, and insulin-like growth factor-1 (IGF-1) signalling during puberty, which may have a causal role in pathogenesis of acne by influencing adrenal and gonadal androgen metabolism.