|Butter, Yogurt, Buttermilk and Milk|
rBST was first developed by a company called Monsato under the brand name Posilac. Posilac was designed to be given to cows to produce more milk over the course of lactation by preventing or delaying the natural mammary cell death that happens during lactation. "To apply Posilac for maximum effect, farmers are recommended to make the first Posilac application about 50 days into the cow's lactation, just before she peaks. The Posilac then sustains already-present mammary cells, limiting the rate of production decrease after production peaks. After the peak, production declines with or without application of Posilac, but declines more slowly with Posilac than without. This decrease in the rate of production decline permits dairy cows to produce more milk over the span of a lactation—at its best, this will be seen by seven to eight more pounds of milk being produced per day than would be produced without Posilac." Posilac is available without a prescription and can be bought and administered by a farmer without the guidance of a veterinarian.
The Food and Drug Administration (FDA), approved the use of Posilac in 1993 after "determining that its use would be safe and effective. Part of the FDA’s safety evaluation was to ensure that milk from treated cows was safe for human food." "FDA believes that the available data confirm that biologically significant amounts of rbGH are not absorbed in humans following the consumption of milk from cows treated with rbGH."
The FDA currently does not require dairy products to be labeled as having been derived from a cow treated with rBST. "The agency found that there was no significant difference between milk from treated and untreated cows and, therefore, concluded that under the Federal Food, Drug, and Cosmetic Act (the act), the agency did not have the authority in this situation to require special labeling for milk from rbST-treated cows. FDA stated, however, that food companies that do not use milk from cows supplemented with rbST may voluntarily inform consumers of this fact in their product labels or labeling, provided that any statements made are truthful and not misleading."
If rBST is "safe and effective," why is there controversy surrounding its use? It turns out that cows treated with rBST have higher levels of IGF-1. According to the American Cancer Society, IGF-1 is a hormone that "helps some types of cells to grow. Several studies have found that IGF-1 levels at the high end of the normal range may influence the development of certain tumors. Some early studies found a relationship between blood levels of IGF-1 and the development of prostate, breast, colorectal, and other cancers, but later studies have failed to confirm these reports or have found weaker relationships. While there may be a link between IGF-1 blood levels and cancer, the exact nature of this link remains unclear." "More research is needed to help better address these concerns."
The second controversy involves a side effect of rBST. Cows treated with rBST tend to develop more mastitis (udder infections). As a result, they are given more antibiotics than cows not treated with rBST. If a cow is given more antibiotics, does it cause more antibiotic resistance and if so, does that resistance pass onto humans? Will the organisms treated by these antibiotics be harder to eradicate if it were to infect a human? This issue has "not been fully examined in humans."
A third controversy involves the effect rBST has on cows. The European Union (EU) has banned the use of rBST based on the effects on the cow and not the effects on humans. In cows, rBST "causes substantially and very significantly poorer welfare because of increased foot disorders, mastitis, reproductive disorders and other production related diseases. These are problems which would not occur if BST were not used and often results in unnecessary pain, suffering and distress. If milk yields were achieved by other means which resulted in the health disorders and other welfare problems described above, these means would not be acceptable. The injection of BST and its repetition every 14 days also causes localised swellings which are likely to result in discomfort and hence some poor welfare. BST use causes a substantial increase in levels of foot problems and mastitis and leads to injection site reactions in dairy cows. These conditions, especially the first two, are painful and debilitating, leading to significantly poorer welfare in the treated animals. Therefore from the point of view of animal welfare, including health, the Scientific Committee on Animal Health and Animal Welfare is of the opinion that BST should not be used in dairy cows."
Like the Europeans, Canadians have also banned the use of rBST based on the effects of the cow and not on the effects on humans. "The veterinary experts cited an increased risk of mastitis of up to 25%, of infertility by 18%, and of lameness by up to 50%. These increased risks and overall reduced body condition lead to a 20-25% increased risk of culling from the herd. The findings of the animal safety committee, when combined with our own assessment, made it quite clear that Health Canada had to reject the request for approval to use rbST in Canada, as it presents a sufficient and unacceptable threat to the safety of dairy cows. The safety of both human and animal health are critical considerations when assessing a new veterinary drug."
It appears that the US is the only major country still using rBST. However, despite the FDA's position that rBST is "safe and effective" many companies like Safeway, Starbucks and Tillamook are pledging to eliminate using milk products from cows treated with rBST. Obviously, controversy is brewing with Monsato, the sole manufacturer of Posilac. They stand to lose millions of dollars if more consumers opt out of purchasing milk from cows treated with their medication. It is estimated that the company has spent "a much as $1 billion in research and development and makes upward of $270 million a year on sales of rBST."
On a personal level, as an animal lover and a mother, I am opting to buy products that do not come from cows treated with rBST. Until more studies are done regarding the long term effects of growth hormone, I cannot justify exposing my children to that risk however small that may be at the moment. Furthermore, it appears the cows really do suffer when given this medication. This is another product that I can add to avoid. Since this uses recombinant DNA technology, it would be considered by my definition, a genetically modified organism.