Last year, the journal Food and Chemical Toxicology announced its retraction of a study done by Gilles-Eric Seralini and colleagues asserting that rats fed genetically-modified corn suffered significantly more malignant tumors than rats fed unmodified corn. Unfortunately, the study was republished this week in the journal Environmental Sciences Europe. Yet, the criticism remains the same.
The study s findings remain as baseless as ever: the strain of rat called the Sprague-Dawley Rat, which was used in the study, is well-known to have a significant predisposition to developing breast tumors; furthermore, 25 percent of the rats in the control (non-GMO-fed) group got tumors and died while some of the test groups were healthier than the control group. This breed of rats is routinely used for toxicity and carcinogenicity studies in pharmaceutical research for precisely this reason. These rats pick up toxicity and carcinogenicity signals quickly, but are prone to false positives.
Another fact to note: the groups were not equally matched with only 20 controls and 80 test rats. However, the key point which negates the plausibility of this study is that researchers did not find a dose-response. With toxicology studies, toxic effects are supposed to worsen with higher doses of the substance. Without dose-response, cause and effect conclusions cannot be made, nor even inferred.
And of course, the study was funded by the Committee for Research and Independent Information on Genetic Engineering, with Seralini as the head of the scientific board. The mission of the group is to make every effort towards the removal of the status of secrecy prevailing in genetic engineering experiments and concerning genetically modified crops (GMOs), both being likely to have an impact on the environment and/or health.
We congratulated the journal Food and Chemical Toxicology for retracting the study last year, and we hope that soon, the journal Environmental Sciences Europe will do the same thing.