Doin’ a Body Good? Studies Link rBGH-Produced Milk and Increased Cancer Risk

Those white mustaches on the smiling faces of celebrities may be a clever way to promote the “milk does a body good” idea. But there’s nothing amusing about increasing evidence of much higher rates of breast and prostate cancers in people who have elevated levels of Insulin-Like Growth-Factor 1 (IGF-1), the hormone that increases milk production in cows treated with recombinant Bovine Growth Hormone (rBGH). Recently, consumers have been voting with their pocketbooks, electing to pay more to protect their health by purchasing organic milk.

“Ever since rBGH went on the market, sales of organic milk have greatly increased,” says Ronnie Cummins, director of the Pure Foods Campaign, a consumer advocacy group. “In 1994 and 1995, organic milk consumption jumped 150 percent. In 1996, it increased 100 percent, and in 1997, 50 percent. There has been phenomenal growth in the organic milk market exactly because of concerns about rBGH.”

Scientific studies published this year are likely to send even more consumers over the barnyard fence to rBGH-free milk. A study of U.S. women published May 9 in Lancet, the British medical journal, showed a seven-fold increase in breast cancer among pre-menopausal women who had the highest levels of IGF-1 in their bodies. A study published in January in the journal Science linked higher levels of IGF-1 in men with a four-fold increase in prostate cancer.

Hormones in Disguise

Monstanto avoids using the word hormone by marketing rBGH as rBST (recombinant Bovine Somatotropin). The hormone stimulates milk production indirectly by increasing cows’ levels of IGF-1, resulting in high levels of the hormone in rBGH-treated livestock. While it hasn’t been proven that drinking milk or eating dairy products with increased levels of IGF-1 also increases levels of IGF-1 in the body and cancer risk in humans, the authors of the Lancet study on breast cancer note there is “substantial indirect evidence of a relation between IGF-1 and the risk of breast cancer.” Experiments have further shown that IGF-1 enhances the growth of cancerous breast cells in mice.

The new studies linking higher rates of cancer with higher rates of IGF-1 in cancer patients haven’t caused the Federal Drug Administration (FDA) to reconsider approval of rBGH. “To date there is no indication that it causes any problems that would warrant a change in its labeling or approved status,” said FDA press spokesman Brad Stone.

For its part, Monsanto strongly defends rBGH, asserting that, because the hormone does not accumulate in cows’ bodies, there’s no difference between treated and untreated milk. According to Gary Barton, Monsanto’s director of biotechnology communications, “Milk has always had IGF-1 in it—it’s naturally occurring. The critics, who have been out there for at least 15 years, have leapt on these scientific articles and tried to make a link between rBGH, cow’s milk and increased levels of IGF-1, when in fact there is no link.”

Barton notes that the Science article was reviewed as part of an investigation by the United Nations Food and Agriculture Organization earlier this year, and that the review concluded that “there are no food safety or health concerns related to [rBGH] residues in products such as milk and meat from treated animals.” (The UN report does, however, note slightly elevated levels of IGF-1 in treated milk, a range of one to 13 nanograms per milliliter, compared to one to nine nanograms for untreated milk.)

The official exoneration doesn’t surprise people like Cummins, who consider the FDA irresponsible in approving the use of rBGH. “There is mounting scientific evidence that IGF-1 is a potent chemical hormone and that people who have higher levels of IGF-1 in their bodies also have much higher rates of prostate, colon and breast cancer,” Cummins says. “That should be a clear warning sign that this product has to be looked at more carefully.” He adds that a 1996 U.S. Department of Agriculture poll found that “94 percent of Americans said they wanted mandatory labeling of rBGH, and 74 percent of Americans believe that this is a dangerous drug.”

Cummins further notes that Monsanto has previously admitted to health authorities in the U.S. and Europe that the milk products from cows treated with rBGH have higher levels of IGF-1. “And now they’re denying it,” he says. “That’s ridiculous. There is plenty of scientific data that shows IGF-1 levels in cows and dairy products are significantly higher. We’re talking not 25 percent higher, but 400 percent higher.” Although the studies have primarily looked at cancer rates in adults, the impact on children’s health is also of considerable concern. Children are susceptible to even small changes in the hormone system, and generally consume more diary products than adults.

But there has been progress on the issue of labeling products as rBGH-free. Ben and Jerry’s Ice Cream was joined by three other companies—Stonyfield Yogurt, Organic Valley Family of Farms, and Whole Foods Markets—to sue the State of Illinois and the City of Chicago over the right to label products as rBGH-free. And since labeling laws vary state by state, labeling restrictions such as those imposed by Illinois were preventing companies from marketing their products nationwide as rBGH-free.

The lawsuit was settled out of court in August 1997 in favor of the organic companies. Ben and Jerry’s spokesman Lee Holden says winning the lawsuit was a significant factor in allowing the company to redesign its labels to have an anti-rBGH message featured prominently on every pint of ice cream sold in the U.S. and in foreign countries. Monsanto’s Barton dismisses Ben and Jerry’s label as “a marketing gimmick,” adding that the company can’t guarantee there isn’t rBGH milk in many of its added ingredients, like chocolate chips and cookie dough.

Finding Clean Milk

Dave Rapaport, executive director of the Vermont Public Interest Research Group, notes that labeling requirements vary state by state, and consumers may find it difficult to find milk labeled rBGH-free in the supermarket. “If you are not able to find products that are clearly labeled as not using rBGH, contact your local diary producers and urge them to make them available,” Rapaport suggests.

Yet, most likely, your milk is part of the untreated majority. Dr. Michael Hansen, a research associate with Consumers Union, claims Monsanto has stopped releasing U.S. sales figures, but he estimates that only about five to 10 percent of dairy cows in the U.S. are being treated. He adds that some dairy farmers are primarily using the product to increase milk production in their older cows. Monsanto’s Barton disputes Hansen’s figures, asserting that 25 percent of American cows are in herds treated by rBGH, and that because milk from many dairies is mixed together, essentially all milk is treated.

In states where milk products labeled as rBGH-free aren’t available, consumers concerned about such hormones should consider organic milk products. Purchasing rice or soy milk, which natural food advocates say is more healthy than milk anyhow, is another alternative.

It is important, also, to lobby state legislatu

res to allow the labeling of rBGH-free products. The marketplace acceptance of rBGH, the first major agricultural biotech product, could have a big impact on what other genetically engineered foods may be on the supermarket shelves in the near future.

“There is a lot at stake for the whole biotechnology industry,” Rapaport says. “Monsanto has invested a tremendous amount of money in rBGH, and there are all kinds of companies behind them with engineered foods. They feel like if this gets held up, it affects their chances.”