Stephen Walsh, PhD, Science Coordinator for the International Vegetarian Union, wrote in a Nov. 2001 article titled "Milk and Breast Cancer," posted on the VegSource website:

“Consuming milk increases levels of a growth hormone, IGF-1, in the body. Increased IGF-1 levels are strongly implicated in prostate cancer, colorectal cancer, premenopausal breast cancer and lung cancer. The effect of milk on IGF-1 may be due to absorption of IGF-1 from the milk or may simply be due to the high protein and zinc content of the milk.”

Nov. 2001