CAMBRIDGE, MASS. — The research journal Food and Chemical Toxicology has retracted a study published in November 2012 titled “Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize,” by Gilles Eric Séralini et al. that showed rats fed bioengineered corn were more likely to develop cancer than rats fed non-bioengineered corn.

The raw data used in the study revealed no definitive conclusions could be reached with the small sample size used to determine overall mortality or tumor incidence, according to a statement released by the publication.

“Given the known high incidence of tumors in the Sprague-Dawley rat, normal variability cannot be excluded as the cause of the higher mortality and incidence observed in the treated groups,” the statement said.

Shortly after the article was published the peer-reviewed journal received several letters to the editor expressing concerns about the validity of the study’s findings. Due to the nature of the concerns raised about the paper, the publication’s editor-in-chief launched a review of all aspects of the peer review process and requested permission from the corresponding author to review the raw data. It was in the review of the raw data where the flaws in the study were identified.