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The Use of Bovine somatotropin (bST) in Milk Production

Adam J. Lieberman and Simona C. Kwon, M.P.H.
Facts Versus Fears: A Review of the Greatest Unfounded Health Scares of recent Times
American Council on Science and Health
SOURCE: http://www.acsh.org/publications/reports/facts3.pdf

Bovine somatotropin (bST) is a natural hormone that stimulates milk production. Biotechnology companies began manufacturing a genetically engineered version of bST in the early 1990s.

On November 5, 1993, the FDA approved genetically engineered bST for commercial use in the United States. Treating dairy cows with this hormone increases milk production by as much as 20 percent, and no detectable difference has been found between milk from treated cows and milk from untreated cows. The hormone bST has no adverse effects on the health of treated cows, and milk and meat from bST-treated cows are both safe for human consumption.

Scientists throughout the world—researchers working in academia, in government, and in the dairy industry—conducted more than 2,000 scientific studies of bST. The studies show clearly the efficacy, the safety, and the benefits that can be realized by integrating bST into dairy production technology. To stem the tide of misinformation about bST, the FDA itself—in an unprecedented move—sponsored a 1990 article in Science magazine stating that bST was perfectly safe.

But despite the scientific data and the proved efficacy of bST, opposition arose. One day before U.S. sales of milk from treated cows began, consumer activists dressed up in cow suits and dumped milk to protest the use of bST. Jeremy Rifkin, the president of the Foundation for Economic Trends, raised particularly vigorous objections to the introduction of bST.

Because Rifkin could not present a convincing case to the FDA, the EPA, or other scientific groups, he decided to take his case directly to the people. Rifkin and others used the popular press to make unsubstantiated claims that the use of bST would increase the incidence of antibiotic-resistant infections and increase milk drinkers’ risk of developing allergies. Neither of these claims is true, however.

Like all other plant and animal proteins in the human diet, bST is destroyed during the digestion process. It therefore has no effect on people who consume it. Furthermore, bST is inactive in humans even when injected: The makeup of bovine somatotropin is significantly different from that of human somatotropin, and human cells can neither identify nor react to the bovine hormone.

Recently, the activists’ attention has turned to Insulin-like Growth Factor (IGF-1), a protein hormone. This hormone, which is stimulated by naturally occurring bST, converts nutrients into milk. Both humans and cows possess IGF-1. Although supplemental bST does increase IGF-1 levels in the milk of treated cows, treating cows with the hormone increases the level of IGF-1 in their milk to only two to five parts per billion more than the levels that occur naturally in untreated cows.

The fear of increased IGF-1 levels in milk has, indeed, led to a scare, because IGF-1, estrogen, and organochlorines in milk have all been linked to breast cancer. The FDA has dismissed this scare, however, and has concluded that the claim that IGF-1 milk promotes breast cancer is scientifically unfounded.

Despite the body of scientific evidence and bST’s approval by the FDA, scares centering on the hormone’s use in milk production are likely to continue because of the public’s apprehension about the use of biotechnology to enhance the food supply. This continuing uneasiness is evidenced by a label displayed on the carton of every Ben & Jerry’s ice cream product—a label stating the company’s commitment to the use of "natural ingredients" and expressing disapproval of the use of bST in cow’s milk.

Conclusion

Public concern over these three "not-quite-great" scares—fluoridation, irradiation, and bST—has not mounted to a high pitch of anxiety. But the existence of these "lesser" scares does point up the American public’s generalized fear of the unfamiliar—a fear not easy to dispel. And scaremongers habitually try to exploit this uneasiness—the vague feeling of misgiving that people commonly display in response to unfamiliar technologies and scientific innovations.

Unfortunately, the consequence of these scare tactics is twofold: Much time, effort, and money are spent refuting the scaremongers’ false claims; and the activists’ playing of the scare card delays the benefits these new technologies and processes have to offer. The public’s anxiety about irradiation, for example, delayed its approval for the pasteurization of meat products in the U.S.—despite the fact that the process can kill E. coli and so might have halted the foodborne illnesses and deaths that preceded Hudson Food’s recall of 25 million pounds of beef in the summer of 1997.

Thus, even as the activists are mounting scare campaigns to try to convince people that the increased use of chemicals and new technologies are increasing their health risks, the scientific evidence is demonstrating that technology is, in fact, helping to make the world a better—and safer—place.

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