Controversy over milk hormone safety
In late 1993, the US Food and Drug Administration (FDA) gave permission for Monsanto corporation to market rBGH, a genetically engineered hormone that is injected into dairy cows to make them produce more milk. In 1990, FDA had declared rBGH (recombinant bovine growth hormone), "safe for human consumption".
Now the scientific validity of FDA's 1993 safety decision is being challenged by Canadian government scientists. Consumers Union (the publisher of Consumer Reports magazine) and other US consumer groups have called for a Congressional investigation into FDA's 1993 decision to approve rBGH.
Tens of thousands of US dairy cows are injected with rBGH each week, and virtually the entire US citizenry is exposed to milk from rBGH-treated cows through milk, other dairy products and baked goods.
No other country has approved rBGH for use within its borders, though Monsanto has sought approval in Australia, New Zealand, the European Union and Canada.
In 1990, in Science magazine, FDA published a justification for its conclusion that milk from rBGH-treated cows was "safe for human consumption". Such a public justification of a pending decision is highly unusual, perhaps indicating the politically charged nature of FDA's decision.
FDA's article offered seven tables of data to support its conclusion that rBGH is safe. The first two tables were taken from an unpublished Monsanto study of rats fed rBGH in high doses for 90 days.
In Science, FDA said the 90-day rat feeding study showed that rBGH "is not orally active in rats" and concluded, "No oral activity was found when rBGH was administered to rats at exaggerated doses".
However, a Canadian government report released late last year indicates that the findings of Monsanto's rat study were misreported by FDA.
The Canadian report says that 20-30% of the rats fed rBGH in high doses developed primary antibody responses, indicating that rBGH was absorbed into their blood.
Furthermore, cysts reportedly developed on the thyroids of the male rats and some increased infiltration of the prostate gland occurred. Despite these results, FDA reported in Science that there were "no clinical findings" in the Monsanto rat study.
The Canadian government report concludes flatly that "the three month rat study did show a physiological response".
One FDA official told the Associated Press in October that FDA never examined the raw data from Monsanto's rat feeding study but based its 1993 safety conclusion only on a summary of the study provided by Monsanto.
Drawing conclusions from a summary of a scientific study would be equivalent to describing the contents of a book by reading an author's summary instead of the book itself.
Furthermore, relying on a summary of a study, rather than on detailed data from the study, would violate FDA's published procedures. In its 1990 Science article, FDA said, "The FDA requires the pharmaceutical companies to submit all studies they conducted on their products" and, "The companies also submit the raw data from all safety studies that will form the basis of the approval of the product".
Furthermore, FDA explained, "If the initial toxicity study demonstrates that the protein is indeed orally active, additional testing may be required".
The same rat-feeding study has also proven controversial in Canada. A Canadian legislator, Mira Spivak, whose committee is investigating the approval process for rBGH in Canada, says Canadian health officials provided her staff with a copy of the Monsanto study in which the information about the potentially troubling effects of rBGH on rats was "blocked out".
The Canadian government report says that levels of IGF-I (insulin-like growth factor-1) are elevated in the milk produced by rBGH-treated cows. IGF-I is identical in cows and in humans.
The Canadian report notes that US FDA acknowledges that IGF-I is increased in milk from rBGH-treated cows. The Canadian report concludes, "There is insufficient information [about IGF-I] to provide a quantitative risk assessment; therefore, many potential health concerns remain unresolved".
The Canadian report offered additional data which, if corroborated, could have prevented US FDA from approving rBGH.
FDA says that, before a drug can be approved for use in animals, "the company must show that the drug is effective and safe for the animal". The Canadian report says, "Evidence from the animal safety reviews were not taken into consideration. These studies indicated numerous adverse effects in cows, including birth defects, reproductive disorders, higher incidence of mastitis, which may have had an impact on human health."
Furthermore, the Canadian government report says, "There are reports on file that Monsanto pursued aggressive marketing tactics, compensated farmers whose veterinary bills escalated due to increased side effects associated with the use of rBST [rBGH], and covered up negative trial results. All the four US manufacturers [Monsanto, Eli Lilly, Cyanamid and Elanco, with only Monsanto actually marketing a product] refused to disclose the lists of their research grants to US universities."
Without such lists, one could not inquire what effects (if any) had been revealed by animal experiments.
The Canadian government report concludes that, in Canada, "Both procedural and data gaps were found which fail to properly address the human safety requirements of this drug under the Food and Drugs Act and Regulations".
It is evident from the Canadian report that the US approval process for this drug was equally flawed. None of the questions raised by the Canadian government scientists have been addressed by US FDA.
[From Rachel's Environment & Health Weekly. Like Green Left Weekly, Rachel's is a non-profit publication which distributes information without charge on the internet and depends on the generosity of readers to survive. If you are able to help keep this valuable resource in existence, send your contribution to Environmental Research Foundation, PO Box 5036, Annapolis, Maryland 21403-7036, USA. In the United States, donations to ERF are tax deductible.]
BY PETER MONTAGUE