ok. so i found some pretty scary stuff about whey protein. Never knew these effects could take place. Seems to be a serious problem, or is it just hype?
Whey Also Contains Insulin Growth Factor (IGF-1)
On January 23, 1998 researchers at the Harvard Medical School released a major study providing conclusive evidence that IGF-1 is a potent risk factor for prostate cancer. Should you be concerned? Yes, you certainly should, particularly if you drink milk produced in the United States . IGF-1 or insulin-like growth factor 1 is an important hormone that is produced in the liver and body tissues. It is a polypeptide and consists of 70 amino acids linked together. All mammals produce IGF-1 molecules very similar in structure and human and bovine IGF-1 are completely identical. IGF-1 acquired its name because it has insulin-like activity in fat (adipose) tissue and has a structure that is very similar to that of pro-insulin. The body's production of IGF-1 is regulated by the human growth hormone and peaks at puberty. IGF-1 production declines with age and is only about half the adult value at the age of 70 years. IGF-1 is a very powerful hormone that has profound effects even though its concentration in the blood serum is only about 200 ng/mL or 0.2 millionth of a gram per milliliter (1-4).
Insulin-like growth factor (IGF-I) in humans and cows are identical. Like a key fitting into a lock, this hormone is a perfect match between two species of animal and exerts powerful growth effects. IGF-I is the most powerful growth hormone in the human body. Every sip of milk, every bite of cheese, every whey protein drink contains IGF-I.
IGF-1 and Cancer
IGF-1 is known to stimulate the growth of both normal and cancerous cells(2,5). In 1990 researchers at Stanford University reported that IGF-1 promotes the growth of prostate cells(2). This was followed by the discovery that IGF-1 accelerates the growth of breast cancer cells(6-8). In 1995 researchers at the National Institutes of Health reported that IGF-1 plays a central role in the progression of many childhood cancers and in the growth of tumours in breast cancer, small cell lung cancer, melanoma, and cancers of the pancreas and prostate(9). In September 1997 an international team of researchers reported the first epidemiological evidence that high IGF-1 concentrations are closely linked to an increased risk of prostate cancer(10). Other researchers provided evidence of IGF-1's link to breast and colon cancers(10,11).
The January 1998 report by the Harvard researchers confirmed the link between IGF-1 levels in the blood and the risk of prostate cancer. The effects of IGF-1 concentrations on prostate cancer risk were found to be astoundingly large - much higher than for any other known risk factor. Men having an IGF-1 level between approximately 300 and 500 ng/mL were found to have more than four times the risk of developing prostate cancer than did men with a level between 100 and 185 ng/mL. The detrimental effect of high IGF-1 levels was particularly pronounced in men over 60 years of age. In this age group men with the highest levels of IGF-1 were eight times more likely to develop prostate cancer than men with low levels. The elevated IGF-1 levels were found to be present several years before an actual diagnosis of prostate cancer was made(12). The evidence of a strong link between cancer risk and a high level of IGF-1 is now indisputable. The question is why do some people have high levels while others do not? Is it all genetically ordained or could it be that diet or some other outside factor influences IGF-1 levels? Dr. Samuel Epstein of the University of Illinois is one scientist who strongly believes so. His 1996 article in the International Journal of Health Sciences clearly warned of the danger of high levels of IGF-1 contained in milk from cows injected with synthetic bovine growth hormone (rBGH). He postulated that IGF-1 in rBGH-milk could be a potential risk factor for breast and gastrointestinal cancers(13).
found here
http://www.enerex.ca/articles/say%20no%20way%20to%20whey.htm
