Many people argue that raw milk (unpasteurized dairy milk) is good for you and much better than pasteurized milk. The raw vs. Pasteurized debate is a long standing one and is intensifying. According to Wikipedia the debate can be summarized as follows
"The raw vs. pasteurized debate places the alleged health benefits of consuming raw milk against the disease threat of unpasteurized milk. Although agencies such as the Centers for Disease Control (CDC), the Food and Drug Administration (FDA), and other worldwide regulatory agencies say that pathogens from raw milk make it unsafe to consume, other organizations such as the Weston A. Price Foundation in its "Real Milk" campaign say that raw milk has health benefits that are destroyed in the pasteurization process and that it can be produced hygienically. Dr. Joseph Mercola, another promoter of raw milk, says the health benefiting ingredients destroyed during pasteurization include: valuable enzymes, unprocessed natural butterfat, healthy unoxidized cholesterol, conjugated linoleic acid, and its high omega-3 and low omega-6 ratios."
In fact, both sides of the debate are wrong. Raw milk is bad for health and so is pasteurized milk. Why? For a variety of reasons: both types of milk are rich in saturated fat, indigestible protein, mucus forming casein, harmful bovine hormones, and a host of other harmful substances.
But leaving all this aside, there is one undeniable fact: IGF-1 is present in both raw milk and in pasteurized milk in equal quantities. IGF-1 is truly bad news. Any advocate of raw milk cannot escape the fact that however organic, “nutritious”, clean, and pure the milk, it will be rich in IGF-1 hormones. Countless scientific studies published in peer-reviewed journals show that IGF-1 increases the risk of cancer and other illneses in humans.
Here is just a small selection of these studies
• IGF-1 is critically involved in the aberrant growth of human breast cancer cells. (Journal of the National Institute of Health, 1991-3).
• Estrogen regulation of IGF-1 in breast cancer cells would support the hypothesis that IGF-1 has a regulatory function in breast cancer. (Molecular Cell Endocrinology, March, 99-2).
• IGF-1 is a potent growth factor for cellular proliferation in the human breast carcinoma cell line. (Journal of Cellular Physiology, January, 1994, 158-1).
• IGF-1 plays a major role in breast cancer cell growth. (European Journal of Cancer, 29A - 16, 1993).
• IGF-1 produces a 10-fold increase in RNA levels of cancer cells. IGF-1 appears to be a critical component in cellular proliferation. (Experimental Cell Research, March, 1994, 211-1).
• IGF-1 accelerates the growth of breast cancer cells. (Science, Vol. 259, January 29, 1993).
• A strong positive association was observed between IGF-1 levels and prostate cancer risk. (Science, vol. 279, January 23, 1998).
• IGF-1 can affect the proliferation of breast epithelial cells, and is thought to have a role in breast cancer. (The Lancet, vol. 351, May 9, 1998).
• IGF-1 strongly stimulates the proliferation of a variety of cancer cells, including those from lung cancer. (Journal of the National Cancer Institute, vol. 91, no. 2, January 20, 1999).
• IGF-1 is widely involved in human carcinogenesis. A significant association between IGF-1 and an increased risk of lung, colon, prostate, and pre-menopausal breast cancer has recently been reported. (International Journal of Cancer, 2000 Aug. 87:4).
• A raised level of IGF-1 has been associated with breast cancer for women and prostate cancer for men. (Rosemary Hoskins, Food Fact no. 2, A Safe Alliance Publication, 1998).
• By continuing to drink [dairy] milk, one delivers the most powerful growth hormone in nature to his or her body (IGF-I). That hormone has been called the key factor in the growth of breast, prostate, and lung cancer. At the very best, or worst, this powerful growth hormone instructs all cells to grow. This might be the reason that Americans are so overweight. At the very worst, this hormone does not discriminate. When it finds an existing cancer, usually controlled by our immune systems, the message it delivers is: GROW! (Robert Cohen, Milk – The Deadly Poison, Argus Publishing, January 1, 1998, ISBN: 0965919609).
• Several studies have shown powerful associations between IGF-1 and the risk of colon cancer, prostate cancer, and pre-menopausal breast cancer. As a matter of fact, recent evidence indicates that high IGF-1 levels may be more important than other previously reported risk factors for cancer. The pharmaceutical industry is well aware of the increasingly clear association between IGF-1 and cancer. Chemotherapeutic drugs are being developed to block the activity of IGF-1 or enhance the activity of IGF binding protein-3. (Smith, George Davey, et al. Cancer and insulin-like growth factor-I. British Medical Journal, Vol. 321, October 7, 2000, pp. 847-48).
• IGF-1 has been called ‘plug and play cancer fuel’ by many. Here is what Dr. Sarfaraz K. Niazi (PhD pharmaceutical sciences, University of Illinois, USA) has to say regarding hormones in milk
‘Some dairy milk samples also show noticeable concentration of a growth hormone given to cows to promote their growth and increase milk production. Being fat-soluble, hormones are more concentrated in the cream. Hormones in milk are a serious threat to health because even at very low concentrations, they can cause severe imbalance of our physiologic system. They have also been implicated in many types of cancers and decreased resistance to infections and diseases. Though prohibited in some parts of the world, unscrupulous farmers continue to use hormones. Whatever a cow eats shows up in her udders. The grass, silage, straw, cereals, roots, tubers, legumes, oilseeds, oilcakes, and milk by-products, which contain a variety of chemical additives, make the diet of modern cow. The diet of cows is rife with pesticides, fertilizers, herbicides and traces of heavy metals along with chemicals from spoilage. With each glass of milk shoved down little Jane's or Johnny's throat, comes the increased chance of their developing atherosclerosis, cancer, autoimmune diseases, infections and a host of other diseases still unidentified, when they reach adulthood.’
• Levels of IGF-1 ….have been associated with prostate cancer risk in at least three prospective studies. Both in vitro and in vivo experiments have provided abundant evidence that IGF-1 can promote prostate carcinogens, including the observations that IGF-1 administration induces prostate growth in the rat, and that prostate tumor development in transgenic mouse models is accompanied by elevations in IGF-1 expression. Sources: (i) Gann, Peter H., MD, ScD, Risk Factors for Prostate Cancer, Rev Urol. 2002; 4(Suppl 5): S3–S10. PMCID: PMC1476014. (ii) Pollak M. Insulin-like growth factors and prostate cancer. Epidemiol Rev. 2001;23:59–66.
• ‘We showed that IGF-1 can completely take the place of growth hormone” in breast tissue. In other words, IGF-1 can trigger cell growth without an outside cue. Estrogen can amplify the cell-proliferating effects seen with IGF-1, both in the breast and prostate. Excess of IGF-1 or estrogen occurs in the presence of the other which can cause breast hyperplasia (cell division on overdrive) putting one at risk for breast cancer.’ (Kleinberg, David L., et al, Growth Hormone and Insulin-Like Growth Factor-I in the Transition from Normal Mammary Development to Preneoplastic Mammary Lesions, Endocr. Rev., Feb 2009; 30: 51 – 74).