Milk from engineered hormone: udderly safe.

Milk from engineered hormone: Udderly safe

Milk from cows treated with a drug that increases milk production is safe for consumption, a panel of scientists and physicians assembled by the National Institutes of Health unanimously concluded last week. The panel's report rejected arguments by some consumer groups that the drug could harm people and affirmed an earlier Food and Drug Administration finding that the substance lresents no health risk to consumers (SN: 8/25/90, p.116).

When injected into cows, recombinant bovine somatotropin (rBST), sometimes called bovine growth hormone, increases milk production by at least 10 percent. Though the controversial drug -- a genetically engineered version of a hormone occurring naturally in cows -- has not yet won FDA approval for routine use, milk from experimentally treated cows has been sold legally in some states.

"The evidence clearly indicates that overall composition and nutritional quality of milk and meat from rBST-treated cows is equal to that from untreated cows," says panel chairman Melvin M. Grumbach, a pediatrician at the University of California, San Francisco.

Consisting mainly of pediatricians, veterinarians and food scientists, the panel heard three days of testimony from rBST researchers, and sometimes heated objections from drug opponents -- particularly Samuel S. Epstein, a public health professor at the University of Illinois at Chicago, who claimed that companies developing the drug had avoided publishing unfavorable results.

The panel found no evidence of scientific misconduct, and few data to suggest the drug harms cows. However, it admitted a lack of sufficient data to know wheather the hormone increased the incidence of mastitis, a common infection of the udder.

The report also calls for more research to determine whether high doses of IGF-I -- a hormone present at elevated levels in milk from rBST-treated cows -- alters laboratory animal growth. However, panelists found it unlikely that the IGF-I levels in milk would pose a threat to humans, whose saliva already contains comparable concentrations of IGF-I.