Milk

Recently, three epidemiological studies from the same group of scientists found an association between acne and consumption of partially skimmed milk, instant breakfast drink, sherbet, cottage cheese, and cream cheese.[18][19][20] The researchers hypothesize that the association may be caused by hormones (such as several sex hormones and bovine insulin-like growth factor 1 (IGF-1)) or even iodine[21] present in cow milk. Some but not all of these products survive digestion and could have biological effects in humans. Though there is evidence of an association between milk and acne, the exact cause remains unclear.