For nearly twenty years, rbGH (recombinant bovine growth hormone), also known as rbST (recombinant bovine somatotropin), has been a staple in the dairy products consumed by Americans. Since these products are not labeled as containing rbGH / rbST, most consumers have no idea that a growth hormone intended to induce dairy cows to be more productive is in much of their milk, cheese and yogurt. After approving the use of rbGH in 1993, the U.S. Food and Drug Administration (FDA) turned a deaf ear to the appeals of consumers, food safety organizations and scientists to reverse its approval of the hormone, or to simply require labeling of foods containing rbGH. The FDA’s decision stood despite regulatory bodies in both Canada and Europe rejecting the hormone due to numerous animal and human health concerns.
In cows treated with rbGH, significant health problems often develop, including a 50% increase in the risk of lameness (leg and hoof problems), over a 25% increase in the frequency of udder infections (mastitis), and serious animal reproductive problems, such as infertility, cystic ovaries, fetal loss and birth defects. Because rbGH use results in more cases of mastitis, dairy farmers tend to use more antibiotics to combat the infections, the residues of which also may end up in milk and dairy products. These residues can cause allergic reactions in sensitive individuals and contribute to the growth of antibiotic resistant bacteria, further undermining the efficacy of some antibiotics in fighting human infections.
Recent research has also shown that the levels of a hormone called “insulin-like growth factor-1″ (IFG-1) are elevated in dairy products produced from cows treated with rbGH. Canadian and European regulators have found that the FDA completely failed to consider a study that showed how the increased IGF-1 in rBGH milk could survive digestion and make its way into the intestines and blood stream of consumers. These findings are significant because numerous studies now demonstrate that IGF-1 is an important factor in the growth of cancers of the breast, prostate and colon.
Thankfully, consumer outcry over the unlabeled use of rbGH has led to many dairy companies going rbGH-free, and labeling their products as such. Check out the Center for Food Safety’s Guide to rbGH-Free Dairy Products for more information.