Strong Suspicions of Toxicity in One GMO Corn
By Stephane Foucart
March 14, 2007
Allowed to go on the market in France and Europe, MON 863, a transgenic corn invented by Monsanto, has been at the center of a controversy over its innocuousness for over two years (April 23rd, 2004, Le Monde). These debates could resume after the March 13th publication in "Archives of Environmental Contamination and Toxicology" of a study suggesting this genetically modified organism (GMO) is toxic to the liver and kidneys.
According to this work, consumption of MON 863 corn disturbs numerous biological parameters in rats to a greater or lesser extent: weight of the kidneys, weight of the liver, the level of reticulocytes (new red blood cells), the level of triglycerides, etc. Urinary chemistry is also changed, with reductions in excreted sodium and phosphorus going as high as 35 percent. The effects vary with the sex of the animals. "Female rats exhibit an increase in blood fat and sugar levels, and an increase in body weight - all associated with greater hepatic sensitivity," says Mr. Seralini, principal author of this study and, moreover, president of the Research Committee for Independent Research and Information on Genetic Engineering (Criigen). "Among males, the impact is opposite, with a drop in body and kidney weights."
The authors of this work used data drawn from an experiment sponsored by Monsanto, which bore on the study of 400 rats for 90 days. The statistical treatment applied to these data by the experts of the agrochemical firm was published in August 2005, by "Food and Chemical Toxicology." That work brought to light significant variations in biological parameters between animals fed MON 863 and those fed with its isogene - the same plant variety without the genetic modification.
Monsanto researchers, for their part, had concluded that those disparities were within the frame of the natural variability of the measured parameters. The effects produced by the GMO were therefore not considered pathological. As for the "natural variability," it had been established by measuring the same series of data on rats fed with other varieties of non-GMO corn, with different nutritional values from MON 863 and its isogene.
The raw experimental data - over a thousand pages - were kept confidential by the agrochemical firm until Greenpeace obtained an order for its publication in spring 2005 from the Appeals Court of Munster (Germany).
Criigen was thus able to examine the data in detail and to apply a new statistical treatment to them. According to Mr. Seralini, that, notably, consisted of extracting from the raw data the most significant effects specifically imputable to GMO absorption.
"Of the 58 parameters measured by Monsanto," the researcher details, "all those that were altered concern kidney or liver functioning." He continued, "furthermore, Monsanto had deemed that, because the males and the females responded differently, there was no reason for worry." He added, "Yet, the liver, for example, is an organ that reacts differently as a function of sex." In the same way, the fact that the measured biological response was not always in exact correlation with the dose of GMO received was interpreted by the company's experts as proof that the transgenic corn being tested was not the cause. Mr. Seralini contests that principle: "When the disturbances are hormonal, for example, the impact may not be proportional to the dose."
Toxicologist Gerard Pascal, a member, like Mr. Seralini, of the Committee on Bio-molecular Engineering, deems certain that Criigen's conclusions are erroneous. "I reject the analysis of the animals' weight curves, conducted without taking their feeding into account," says Mr. Pascal. "But I agree that the biological responses may vary between males and females and with the principle that the effects of a GMO corn must be compared with its isogene only and not take into account effects produced by other corn varieties."
According to Mr. Pascal, the lack of direct correlation between the GMO doses received and the impacts observed on the hepatic parameters disqualifies the conclusions about liver toxicity. Significant differences with respect to "kidney weight" and "urinary sodium, phosphorus, and potassium" suggest a renal impact. "However," Mr. Pascal recalls, "at my request, the CGB pressed for investigations of the kidneys and had not found any definitive evidence of toxicity" (December 15th, 2004, Le Monde). "The variations in the levels of reticulocytes and eosinophiles (white blood cells) remain," adds M. Pascal. "I don't know how to interpret that, but those are parameters that move around a lot in experiments." As far as Mr. Pascal is concerned, the information developed by Criigen is not of a nature to call into question the favorable opinions delivered with respect to MON 863. "All that is nothing but a personal interpretation," adds the toxicologist.
Criigen's work has been financed by Carrefour and Greenpeace, but, as Mr. Seralini explains, "Unfortunately, today there is no public budget for conducting this type of research." A situation all the more harmful, according to Mr. Seralini, in that, "the whole toxicological study ought to be redone, controlling for hormonal dosages" and, above all, the tests should be continued well beyond 90 days and on species other than the rat to reach a definitive conclusion.
[Translation of the French original: t r u t h o u t French language correspondent Leslie Thatcher. ]