The headlines in the world media and on the Internet were downright apocalyptic: “Massive tumors in rats fed GM maize.” “New study: Rats fed lifetime of GM corn grow tumors; 70% of females die early.” “France orders probe after rat study links GM corn, cancer.” “Shock findings in new GMO study: Rats fed lifetime of GM corn grow horrifying tumors” (this one ended, “Spread the word: GMOs are toxic”).
And on and on.
This latest health Armageddon tempest in a teapot was occasioned by a French study reporting that mice that ate genetically modified corn sprayed with glyphosate — or drank water with glyphosate levels similar to that in U.S. tap water — were much more likely to die, and to die younger.
Results, the French researchers claim, showed female rats fed GMO corn were two to three times more likely to die than rats in the control group that didn’t eat the corn. Fifty percent of males and 20 percent of females that ate the corn died significantly earlier than those in the control group.
“Eating genetically modified corn and consuming trace levels of (glyphosate) chemical fertilizer [?] caused …horrifying tumors, widespread organ damage, and premature death,” one website reported, terming the study “the most thorough research ever published into the health effects of GM food crops” and glyphosate.
This Frankensteinian, we’re-all-being-poisoned-the-sky-is-falling scenario is nothing new by those who would have agriculture revert to mules and manure — and certainly not in France, where opposition to GMOs has been a cause célèbre from Day 1.
Dig deeper into the media fray, though, and there are more reasoned voices behind the headlines. Great Britain’s Science Media Centre noted concerns by a raft of other scientists about the study (http://www.sciencemediacentre.org/pages/press_releases/12-09-19_gm_maize_rats_tumors.htm).
Here are a few of the concerns they cited:
—“There are anomalies throughout the paper that normally should have been resolved through the peer review process.”
—“In my opinion, the methods, stats, and reporting of results are all well below the standard I would expect in a rigorous study; to be honest, I am surprised it was accepted for publication.”
—“The control group is inadequate to make any deduction.”
—“Like most of the GM debate, this work has very little to do with GM… There is good evidence that introducing genes into crops using GM techniques results in fewer changes to the crops than introducing them using conventional breeding.”
—“The first thing that leaps to my mind is, why has nothing emerged from epidemiological studies…where so much GM has been in the food chain for so long? If the effects are as big as reported, and if the work really is relevant to humans, why aren’t North Americans dropping like flies? GM has been in the food chain there for over a decade, and longevity continues to increase inexorably! And if the effects are as big as claimed, why haven’t the previous 100-plus studies by reputable scientists, in refereed journals, noticed anything at all?”
Forbes: 'A carefully orchestrated media event'
In U.S. publications, the business magazine Forbes had an online article, “Scientists smell a rat in fraudulent genetic engineering study,” that cites, among other things, “methodologically flawed, irrelevant, uninterpretable — but over-interpreted — experiments intended to demonstrate harm from genetically engineered plants and the herbicide glyphosate” by the French microbiologist who was the lead researcher.
The author of the Forbes report, Henry I. Miller, a physician and molecular biologist at Stanford University’s Hoover Institution, lists numerous flaws in the study, conflicts of interest, and other problems.
“(These) experiments show that he [the French researcher] has crossed the line from merely performing and reporting flawed experiments to committing gross scientific misconduct and attempting fraud,” Miller writes.
“There is so much wrong with the experimental design that the conclusion is inescapable that the investigators intended to get a spurious, preordained result.”
There is no question, Miller writes, that the publication of the study “was a well-planned and cleverly orchestrated media event … designed to produce exactly the false result that was observed and was deliberately allowed to continue until large, grotesque tumors developed.” The conduct of the study, including the treatment of the animals, “raises serious ethical concerns and questions of scientific misconduct,” Miller writes.
European study: 'Insufficient scientific quality'
Also, The European Food Safety Authority (EFSA) has issued a statement that the paper about the French study “is of insufficient scientific quality to be considered as valid for risk assessment.”
EFSA’s initial review found that “the design, reporting and analysis of the study, as outlined in the paper, are inadequate.” To enable the fullest understanding of the study the Authority has invited authors Séralini et alto share key additional information.
“Such shortcomings mean that EFSA is presently unable to regard the authors’ conclusions as scientifically sound,” the organization’s statement 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 tumors in the rats tested.
“Therefore, based on the information published by the authors, EFSA does not see a need to re-examine its previous safety evaluation of maize NK603 nor to consider these findings in the ongoing assessment of glyphosate.
EFSA assessed the paper against recognized good scientific practices, such as internationally agreed study and reporting guidelines.
Per Bergman, who led EFSA’s work, said: “Some may be surprised that EFSA’s statement focuses on the methodology of this study rather than its outcomes; however, this goes to the very heart of the matter. When conducting a study it is crucial to insure a proper framework is in place. Having clear objectives and the correct design and methodology create a solid base from which accurate data and valid conclusions can follow. Without these elements a study is unlikely to be reliable and valid.”
The director of scientific evaluation of regulated products added that the consideration of possible long-term effects of GMOs “has been, and will continue to be, a key focus of EFSA’s work to protect animals, humans and the environment.”
EFSA’s preliminary review issued today is the first step in a two-stage process, Bergman noted. A second analysis will be delivered by the end of October.
“This will take into account any additional information from the study authors, who will be given an opportunity to supply study documentation and procedures to the Authority to insure the broadest possible understanding of their work. It will also include an overview of member state assessments of the paper and an analysis from the German authorities responsible for the assessment of glyphosate.
Main findings of initial study
Thetask force, whose members were drawn from EFSA’s GMO, pesticide and scientific assessment units, has outlined a list of issues about the paper that would need to be resolved before it could be viewed as well-conducted and properly-reported study.
- The strain of rat used in the two-year study is prone to developing tumors during their life expectancy of approximately two years. This means the observed frequency of tumors is influenced by the natural incidence of tumors typical of this strain, regardless of any treatment. This is neither taken into account nor discussed by the authors.
- The authors split the rats into 10 treatment sets but established only one control group. This meant there was no appropriate control for four sets — some 40 percent of the animals — all of which were fed GM maize treated or not treated with a herbicide containing glyphosate.
- The paper has not complied with internationally-recognized standard methods – known as protocols - for setting up and carrying out experiments. Many of these procedures are developed by the OECD (Organisation for Economic Cooperation and Development).
- For a study of this type, the relevant OECD guideline specifies the need for a minimum of 50 rats per treatment group. Séralini et al used only 10 rodents per treatment set. The low number of animals used is insufficient to distinguish between the incidence of tumors due to chance rather than specific treatment effects.
- The authors have not stated any objectives, which are the questions a study is designed to answer. Research objectives define crucial factors such as the study design, correct sample size, and the statistical methods used to analyze data — all of which have a direct impact on the reliability of findings.
- No information is given about the composition of the food given to the rats, how it was stored or details of harmful substances — such as mycotoxins – that it might have contained.
- It is not possible to properly evaluate the exposure of the rats to the herbicide as intake is not clearly reported. The authors report only the application rate of the herbicide used to spray the plants and the concentration added to the rats’ drinking water but report no details about the volume of the feed or water consumed.
- The paper does not employ a commonly-used statistical analysis method nor does it state if the method was specified prior to starting the study. The validity of the method used is queried and there are questions over the reporting of tumor incidence. Important data, such as a summary of dropouts and an estimation of unbiased treatment effects have not been included in the paper.
- Many endpoints — what is measured in the study — have not been reported in the paper. This includes relevant information on lesions, other than tumors, that were observed. EFSA has called on the authors to report all endpoints in the name of openness and transparency.
- Review of the Séralini et al. (2012) publication on a 2-year rodent feeding study with glyphosate formulations and GM maize NK603 <http://www.efsa.europa.eu/en/efsajournal/pub/2910.htm>