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A study of the University of Caen neither constitutes a reason for a re-evaluation of genetically modified NK603 maize nor does it affect the renewal of the glyphosate approval

29/2012, 01.10.2012

The BfR has scientifically assessed the publication by Séralini et al. (2012)

The authors’ conclusion that rats fed with genetically modified NK603 maize throughout their life have a shorter lifespan than animals fed with conventional maize is not sufficiently corroborated by experiments. This is the conclusion of an assessment conducted by the Federal Institute for Risk Assessment (BfR) following publication of the study "Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize" by Gilles-Eric Séralini and co-authors in the scientific journal "Food and Chemical Toxicology". "The study shows both shortcomings in study design and in the presentation of the collected data. This means that the conclusions drawn by the authors are not supported by the available data", says Professor Dr. Reiner Wittkowski, Vice President of the Federal Institute. Additionally to the statement on NK603 maize the autors concluded that the glyphosate-containing pesticide Roundup may lead to severe health problems and early death which is not sufficiently substantiated by the evidence in the report. In contrary to the authors conclusions, a number of long-term studies on glyphosate as an active substance in herbicides does not indicate any carcinogenic potential, increased mortality, or an impact on the hormonal system of the test animals. However, the BfR is aware of certain co-formulants, that might affect the toxicity of glyphosate containing herbicides.

In mid-September 2012, a scientific team headed by Gilles-Eric Séralini at the University of Caen in France published the results of a long-term study with rats that had been fed genetically modified glyphosate-tolerant NK603 maize. One part of the genetically modified maize had been treated with the glyphosate-containing pesticide Roundup, whereas another portion was untreated. In each case, the maize was given in three doses. In addition, other animals who had been given conventional feed received Roundup via their drinking water, also in three doses. A control group was fed genetically unmodified maize.

The Federal Institute for Risk Assessment (BfR) has assessed the study in terms of its relevance for the evaluation of the health risk of genetically modified glyphosate-tolerant maize NK603 and also with regard to the evaluation of the health risk of glyphosate as an active ingredient of pesticides. On the basis of the publication, the BfR has come to the conclusion that the authors’ main statements are not sufficiently corroborated by experimental evidence. In addition, due to deficiencies in the study design and in the presentation and interpretation of the study results, the main conclusions of the authors are not supported by the data.

The authors concluded that the animals in some of the test groups developed increased incidences of several tumours, and other non-neoplastic lesions and that deaths occurred earlier than those of the control group. One specific criticism is that the number of animals for each group was too small. As such, the study does not comply with internationally recognised standards for studies on carcinogenicity. The rat strain used in the study is characterised by a relatively high spontaneous tumour rate, especially for mammary and pituitary tumours, and the number of animals used is insufficient for assessing the claimed differences between the test groups and the control group.

Furthermore, the authors postulated that the results may be caused by hormonal effects of Roundup as well as constituents of the genetically modified maize. Even this hypothesis is not sufficiently supported by the data presented. Furthermore, the BfR criticises that the glyphosate dose administered was not determined in the studies with the glyphosate-containing pesticide Roundup. In addition, the presentation of the collected data is incomplete.

Due to these shortcomings, the BfR has asked the authors to provide the complete study report including individual animal data. Moreover, it has asked specific questions in order to further assess the reported effects.

About the BfR

The Federal Institute for Risk Assessment (BfR) is a scientific institution within the portfolio of the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). It advises the Federal Government and Federal Laender on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks.


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