The European Food Safety Authority (EFSA) has determined that a recent paper raising concerns about the potential toxicity of genetically modified maize NK603 and an herbicide containing glyphosate contains “serious defects” and "does not meet acceptable scientific standards."
In a final review on Nov. 28, the EFSA issued a statement saying the widely criticized paper by Séralini et al.—which suggested a link between exposure to the substances and increased incidents of tumors in rats—“contains serious defects in its design and methodology, does not meet acceptable scientific standards and there is no need to re-examine previous safety evaluations of genetically modified maize NK603.”
These are the same conclusions of separate and independent assessments that the EFSA and six EU Member States stated following publication of the paper in the journal Food and Chemical Toxicology on Sept. 19, 2012.
The EFSA , which evaluates the safety of GMOs, said it’s not possible to draw valid conclusions about the occurrence of tumors in the rats tested. In other words, unclear study objectives, the low number of rats used in each treatment group, a lack of detail on the feed and treatment formulation, key information missing on the statistical methods employed and incomplete endpoint reporting were all highlighted by member state organizations.
During the review process, EFSA said it asked Séralini et al. to provide further information on their study documentation, although the authority said no such material had reached them before publication of this statement. On Nov. 9, Séralini et al. then published a general reply to the global reactions to their paper although the EFSA concluded it provided only a limited amount of relevant information which failed to address the majority of the outstanding questions raised in the authority’s first statement.
In Séralini et al.’s “Answer to critics” document, they reportedly stated the sample size of their treatment groups was too small to allow them to draw conclusions with regard to long-term carcinogenicity and mortality. EFSA noted this acknowledgment from the authors is inconsistent with the overall conclusions they made in the paper regarding the tumors and mortality.
Per Bergman, who led EFSA’s work, said: “EFSA’s analysis has shown that deficiencies in the Séralini et al. paper mean it is of insufficient scientific quality for risk assessment. In addition, several national organizations were independently mandated by member states to assess this study. These reviews have demonstrated a consensus among a significant part of the EU risk assessment community that the conclusions of Séralini et al. are not supported by the data in the published paper. We believe the completion of this evaluation process has brought clarity to the issue.”
EFSA also noted the emergence of a broad European consensus, with the reviewed member state assessments finding the conclusions of Séralini et al. were not supported by the data presented in the study. Four of the national evaluations found the paper did not provide scientific information that would indicate the necessity to reopen the risk assessment of NK603 or glyphosate. The exceptions were France’s High Council of Biotechnology (HBC) and Italy, whose assessments reportedly didn't examine this issue. Echoing comments similar to the EFSA, member states also identified many of the same weaknesses in the paper’s methodology and design.