Please Don't Fear the Milk
This is an old issue, but I've been hearing so much about milk from cows injected with artificial growth hormones causing premature puberty in girls that I decided to do a little research. So, I started by looking for scary email hoaxes on the urban legends page Snopes.com.
Turns out you do NOT have to fear that milk from cows treated with growth hormones will cause your prepubescent girls to go into puberty early. Although the use of recombinant bovine somatotropin (rBST) used to boost milk production in cows is controversial, the FDA finds that milk from rBST-treated cows is no different from non-treated cows. One of the main problems with the argument that rBST causes premature puberty is that the somatotropins are growth hormones, which don't cross functions with gonadotropins, the sexual development hormones that bring on puberty, especially when applied to different species.
At the Dairy Spot site, I found references to a pediatric study, which says that there are some indications that some girls are entering puberty earlier, but it does not speculate on the causes. The key paragraph from this article follows (which appears to be from the seminal Washington Post article I refer to below and is quoted in most of the related sites):
"Why girls might be maturing earlier, no one knows for sure. Theories abound: Girls are better nourished. They have more body fat these days. They are exposed to more chemicals. But the changes documented in Pediatrics study cannot be attributed, even in part, to bovine growth hormone for one important reason: The data for the study were collected in 1992 and 1993, before rBST was available for dairy herds in the United States (1994). And there’s another problem with the BST and early puberty theory: Children today drink less milk than they did a generation or two ago. According to the U.S. Department of Agriculture (USDA), milk consumption among girls ages 6 to 11 dropped by about one-third from the late 1970s to the late 1990s."
The best article I found on this topic is from the Washington Post called "Tempest in a Glass" (published on October 7, 2003) that even-handedly reports on this issue and debunks not only the early puberty myth, but also the antibiotics residue myth and the growth hormones in milk causes cancer myth.
It appears that although the scientific research concludes that we do not have a problem with the growth hormone and antibiotic regimens we use on cows, there are still some folks--folks with an interest in promoting an "organic" food agenda, including "nonprofits such as the Center for Food Safety, the Environmental Research Foundation, the Organic Consumers Association and the Vermont Public Interest Research Group, along with businesses including Horizon Organic, Ben and Jerry's and Whole Foods"--who believe that these practices are a threat to human health because they simply don't trust the scientific research of the FDA, NIH, or the WHO and smell a conspiracy between government and large food corporations. And as a result of their campaign of misinformation, many consumers don't seem to be getting the message that their milk is safe.
So, after reading the Post article, do you think that these myths might be the work of the "organic" milk industry that is using fear to boost sales? Or do we really have something to fear? I think the science concludes that we don't have a problem here. So, unless you like paying amount twice as much for "organic" milk, I think you can sleep easy at night knowing that among the many possible environmental hazards you face every day, your milk isn't one of them.