Milk intake may affect acne severity through the Insulin-like Growth Factor-1 (IGF-1) pathway. In two large cross-sectional studies, milk consumption was positively associated with higher plasma IGF-1 levels[20,21] and in both studies, this was predominantly an association with skim milk. In a randomized clinical trial of the effect of milk intake on bone remodeling, intakes of skim and low fat milk were associated with increased serum IGF-1 levels in both sexes.[22] It is not clear whether the increased IGF-1 is endogenous—released in response to milk intake—or exogenous IGF-1 from milk. Human and bovine IGF-1 share the same amino acid sequences [23] and several milk proteins, including IGF-binding proteins (IGFBPs) protect IGF-1 from digestion in the gut.[24,25] Animal studies have shown that milk borne IGF-1 can be absorbed after oral intake.[24] IGF-1 directly stimulates basal keratinocytes' proliferation.[26,27] Although both serum androgens and IGF-1 levels rise at puberty, the period of maximum prevalence of acne and the course of the condition follow the levels of IGF-1 more closely than levels of androgens.[28] There is also a stronger correlation in women between acne lesions and IGF-1 compared to androgens.[29]
Milk intake may influence comedogenesis because it contains several bioactive molecules that can act on the pilosebaceous unit including androgens, 5α-reduced steroids and other steroid hormones.[30,31] Many of these bioactive molecules survive processing and in the case of cheese, fermentation results in the production of more testosterone from precursors in milk.[31] The level of androgens in milk has generally been considered low and first-pass metabolism in the liver may further reduce its bioavailability compared to the daily endogenous production in young children and adolescents. However, recent studies have questioned the methodology and assays on which estimates of daily production rates of endogenous steroid hormones in pre-pubertal children are based.[32] Dietary intake may be a more significant source of androgens than previously thought.[33] Milk also contains estrogens, some of which are produced in the lactating bovine mammary gland and are direct suppressors of sebaceous gland function.[28]
Some hormones in milk are carried by whey proteins, including α-lactalbumin, which also have intrinsic biological functions.[34] Animals fed α-lactalbumin-enriched whey protein show increased will and capacity to engage in physical activities, gains in lean body mass, improved efficiency of exercise training, and decreased percentage body fat mass; all of which are similar to the effect of androgens.[35,36,37] In addition, α-lactalbumin undergoes pressure-induced conformational alteration, possibly because of centrifugation stresses during processing; this leads to changes in biological function.[38] Whey proteins are also added to low fat and skim milk to simulate the consistency of whole milk. These proteins might therefore play a role in acne.
http://www.medscape....rticle/537367_4
EDIT :This link doesn´t work. I don´t know why. If you write in Google: "Milk intake may affect acne severity", you will find it (It is the first link)
Here´s is an article of Loren Cordain (The Paleo Diet): http://www.thepaleod.....e Article.pdf
I take whey protein in my breakfast and i have breakouts of acne ...maybe whey protein it´s not good for me?? I am starting a low GI diet. Should i eliminate whey ?
Edited by glexia, 04 November 2006 - 02:20 PM.
