i checked out a few websites and this is what i found:
Other scientists, working in Wisconsin USA, Germany, and Scotland (Edinburgh and Glasgow) showed in the early 1970s that milk contains progesterone; that is a product of the cows' pregnancy; and that there are other hormones in the milk of pregnant cows, particularly in the butterfat fraction. Also, it was shown that the enzymes necessary to convert these hormones to DHT are present right in the oil glands themselves.
Testosterone (an androgen hormone) targets the skin and the sebaceous glands where sebum is produced. It combines with the enzyme 5alpha-reductase to produce dihydrotestosterone, which stimulates the sebaceous glands to produce increased volumes of sebum. Sebum is expelled out into the follicular tube.
[Are there steroid hormones in cow's milk? The Journal of
Endocrine Reviews in 1992 listed 59 hormones in every sip of
bovine milk (Volume 14, 6):
"Hormones found in cow's milk include: Estradiol, Estriol,
Progesterone, Testosterone, 17-Ketosteroids, Corticosterone,
Vitamin D, insulin-like growth factor, growth hormone,
In September of 1999 (Volume 140;9), the Journal of
Endocrinology identified two milk hormones that accelerate
sebum production. These growth factors are IGF-I and GH.
The Journal of the American Dietetic Association published a
dairy industry-financed study (Volume 99, no. 10, October
1999) confirming the fact that serum IGF-I levels increase
in milk drinkers.]
increased sebum production is one of the major causes of acne. now i understand why milk chocolate may influence acne in some people. dark chocolate does not contain dairy so it might be ok, its certainly better than milk chocolate.
i wish i had learned all of this a long time ago. the scientific evidence is certainly out there. now i gotta investigate how to stay healthy without dairy. it just never ends.