 The National Dairy Council denies that milk intake causes acne, citing the American Academy of Dermatology. Let's take a peek, shall we, at the official journal of the American Academy of Dermatology. The Harvard Nurses Study, no less. A study, in fact, supported by the National Dairy Council itself. High school dietary dairy intake and teenage acne. They studied 47,000 women. What did they find? We found a positive association with acne for intake of total milk and skim milk. We hypothesized that the association with milk may be because of the presence of hormones and bioactive molecules in milk. Yeah, but there's a difference between association and causation, from the accompanying editorial in the Journal of the American Academy of Dermatology. The papers from the Harvard School of Public Health establish an association between milk consumption and acne. But how could milk cause acne? Because drinking milk and consuming dairy products from pregnant cows exposes us to the hormones produced by the cows' pregnancy, hormones that we were not designed to consume during our teenage and adult years. It is no secret that teenagers' acne closely parallels hormonal activity, so what happens if exogenous hormones are added to the normal endogenous load? And what exactly is the source of these hormones? Consider that in nature, milk is consumed from a mother, whether human or bovine, until weaning occurs. Normally, the mother then ceases lactation before the next pregnancy occurs, so that consuming milk from a mother pregnant with her next offspring is not a common occurrence. We've all seen nature films of animals chasing their offspring away to encourage weaning at the appropriate time. Further, in nature, the offspring consumes only the milk of its own species, but both of these natural rules are broken by humans. Viewed objectively, human consumption of large amounts of another species' milk, especially when that milk comes mainly from pregnant cows during the human's normally post-weaned years, is essentially unnatural.