A reader pointed me to an article by Jon Entine, published by the American Enterprise Institute, that questions the methodology used by Séralini to conclude that rats fed genetically modified corn developed grotesque tumors. I’ve posted an excerpt from the article below. You can find the entire article here.
The study concluded, controversially, that rats fed corn genetically modified for herbicide resistance (NK603), with or without the herbicide, Monsanto’s Roundup, developed grotesque tumors—findings that contradict known studies, dozens of them, published to date.
More than two dozen scientists from around the world co-signed a stinging rebuke of the Séralini study, concluding: “We appeal to you to subject the paper to rigorous re-review by appropriate experts and promptly retract it if it fails to meet widely held scientific standards of design and analysis, as we believe it fails to do.”
Séralini and his seven co-authors mount their own defense in Food and Chemical Toxicology. They dismissed most of the criticism as coming from industry sympathizers or corporate scientists, claiming they had “no right to review the results” because of their alleged conflicts of interest. They produced a chart to respond to some of the criticisms, and offered more substantive responses on some issues, for example defending the choice of a rat strain prone to tumors. They reiterated their refusal to release their raw data, yet concluding, defiantly, “GM NK603 and R cannot be regarded as safe as long as their safety is not proven by further investigations.”
Another study conducted by Australian and U.S. researchers and published in the Journal of Organic Systems found:
“…few statistically significant differences between the two groups after comparing them based on nearly 20 different parameters, including weight gain, stomach ulcers and kidney abnormalities. The GM-fed pigs did, however, show significantly higher rates of “severe” stomach inflammation, as well as an average of 25 percent heavier uteri in relation to body weight.”
Here’s the number the study’s authors highlight as most concerning: 23 GM pigs had severely inflamed stomachs, while only 9 non-GM did. That much of a difference is a red flag deserving of further study, said Michael Hansen, Ph.D., senior scientist for Consumers Union.
This study, too, is mired in controversy based on the methodology used. The point of contention “lies in the potential variance in nutritional composition between the GM and non-GM grain fed to the pigs in the study.”
Because of patent-holder restrictions, the researchers were required to buy each type of feed from retail distributors, as opposed to growing the feed in a controlled environment.
According to the study’s authors, the GM corn and soy used in the study were considered compositionally and substantially equivalent to the non-GM varieties by government agencies. But the lack of a controlled feed-growing environment potentially calls the results into question, according to Kent Bradford, Ph.D., director of the Seed Biotechnology Center at the University of California, Davis.
“These are different products,” Bradford told Food Safety News. “For example, soy beans can have a wide range of phytoestrogens. The amount varies widely by production.”
And here we come to the grist of the matter:
Anyone who buys GM seeds is required to sign a technology stewardship agreement that says, in part, that they cannot perform research on the seed. Without express permission from the biotech patent-holder, scientists and farmers risk facing lawsuits for conducting any studies.
“Any study you want to do with these engineered crops, you need to get the company’s permission,” Hansen said. “Could you imagine if tobacco research was only done when the tobacco companies had the final say?”
In July 2009, a group of 26 public sector scientists wrote to the U.S. Environmental Protection Agency to complain about the restrictions imposed on them by the patent holders of GM seeds. In part, they said critical questions regarding GM foods could not be answered without more research freedom, which has still not been established.