Food safety watchdog rejects GM Roundup cancer study

By Mike Stones

- Last updated on GMT

Related tags Efsa Roundup

EFSA rejected the Seralini GM Roundup cancer study
EFSA rejected the Seralini GM Roundup cancer study
The European Food Safety Authority (EFSA) has officially rejected controversial research linking Monsanto’s herbicide Roundup and genetically modified (GM) maize with cancer and premature death.

In the second part of a two-part ruling, the Euro food watchdog said: “Serious defects in the design and methodology of a paper by Séralini et al mean it does not meet acceptable scientific standards and there is no need to re-examine previous safety evaluations of genetically modified (GM) maize NK603.”

EFSA said the verdict reflected the conclusions of separate and independent assessments carried out by its panel of scientific experts and six EU Member States following the publication of the paper in the journal Food and Chemical Toxicology​ on September 19.

The six states were: Belgium, Denmark, France, Germany, Italy and the Netherlands.

Tumours in rats

The research raised concerns about the potential toxicity of GM maize NK603 and of a herbicide containing glyphosate. The research claimed a link between exposure to these substances and an increased incidence of tumours in rats.

The study was led by Professor Giles-Eric Seralini at the University of Caen, France.

The first part of EFSA’s review​ had concluded that “the design, reporting and analysis of the study, as outlined in the paper, are inadequate”.

It said: “The numerous issues relating to the design and methodology of the study, as described in the paper, mean that no conclusions can be made about the occurrence of tumours in the rats tested.”


In its second ruling on the study, EFSA said Member States identified many of the same weaknesses in the methodology and design of the paper as it had raised by EFSA. Those were:

  • Unclear study objectives
  • Low number of rats used in each treatment group
  • Lack of detail on the feed and treatment formulation
  • Key information missing on the statistical methods employed
  • Incomplete endpoint reporting
  • Inadequate sample size

Commenting on the EFSA’s initial finding, a spokesman for Monsanto said: “EFSA’s finding clearly rejects the claims made by Seralini et al. They confirm the existing safety assessment by EFSA and regulatory authorities around the world of Monsanto’s products. 

"Monsanto’s products are subject to detailed scrutiny and safety testing. It is appropriate that claims like those made in the publication by Seralini et al. should be scrutinised in the same way. This is the second high profile paper by Seralini to be rejected by independent regulators.

The spokesman added:“Millions of farmers see the real story about biotech crops every season in their fields, where measurable agronomic, environmental and economic benefits help contribute to their sustainable farming practices.”

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