http://www.mercola.com/2001/aug/22/igf-1.htm
Dr. Mercola's Comment:
My Associate Editor and I had the following letter published on the web site of the Western Journal of Medicine.
It was written in response to a recent Op-Ed piece (West J Med 2001;175:7-9) concerning the use of IGF-1 (insulin-like growth factor-1) by athletes, who use it to enhance their performance. Unfortunately, levels of these growth hormone and insulin mimicking substance are elevated in our milk supply, due to the use of rBGH (also known as rBST) to increase the cow's milk production.
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by Joseph Mercola, DO and Cory Mermer
Adams does an excellent job of discussing the dangers of the exogenous IGF-1, and properly cautions against its use, citing both lack of efficacy and potential adverse effects, such as disruption of the insulin system and carcinogenesis.
However, it is worth noting that much of the US population are unknowingly consuming higher levels of IGF-1 than previously and may face the same elevated risks, since it has been shown that milk from cow's treated with rBGH (Posilac) have significantly elevated IGF-1 levels. Measuring these levels has even been proposed as a basis by which to test for the use of rBGH (1).
In addition, the IGF-1 in the milk of rBGH treated cows is potentially more bioactive than the naturally occurring form and may be increased further by pasteurization (2).
While Adams notes the lack of significant effects of IGF-1 administration in elderly subjects, this certainly does not mean that this would be true for children, who may be at an increased risk of adverse effects.
Children's rapid growth rate may predispose them to be more susceptible to IGF-1. In addition, children's intestines, particularly infants, are naturally more permeable than adults, which could allow greater absorption of the large IGF-1 peptide...............
Ha! This is saying there is free IGF1 in milk....Drink up!