Milk & Cancer Connection

6 Pages 1409 Words

Milk and the Cancer Connection
With complete references for researchers

by Hans R. Larsen, MSc ChE



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 proinsulin. 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).

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 c...