Problems seen in anti-biotech study
CBI has pointed out some of the shortcomings of a paper claiming previously unheard-of health impacts on rats on a diet of biotech corn and weedkiller- a study that some experts think is so questionable that it should not have been published.
“The study published today is a continuation of work that has been denounced by responsible scientific bodies and by scientists who know the subject very well,” the CBI statement said of a paper by Gilles-Eric Seralini, a French biologist, author, and long-time anti-biotech activist.
“Studies by independent scientists have found again and again that food from plants produced with biotechnology is as safe as the same plants produced by conventional means,” the CBI statement said. “More than 400 studies have confirmed the safety of food with biotech ingredients, and not one has documented any ill effect to human health of eating food produced in whole or in part with biotechnology.
Scientists in Europe have pointed out a host of flaws in the current study, including the fact that the rats chosen for the study are known for their tendency to develop tumors. A previous study by Seralini was denounced as invalid by the European Food Safety Authority (EFSA), and experts are very critical of the statistical methods employed in the new study.
“To be honest, I am surprised it was accepted for publication,” said Prof. David Spiegelhalter of the University of Cambridge in England.
Seralini claimed that this was the first long study based on feeding biotech grain to animals. In fact, several other studies as long or longer have concluded that there is no impact from biotech food or feed ingredients, according to a major study published earlier this year in the very same journal that published Seralini’s study (”Food and Chemical Toxicology). Experts were reported to the “skeptical” of the latest from Seralini.
The Reuters news agency reported:
Tom Sanders, head of the nutritional sciences research division at King’s College London noted that Seralini’s team had not provided any data on how much the rats were given to eat, or what their growth rates were.
“This strain of rat is very prone to mammary tumors particularly when food intake is not restricted,” he said in an emailed comment.
“The statistical methods are unconventional and probabilities are not adjusted for multiple comparisons. There is no clearly defined data analysis plan and it would appear the authors have gone on a statistical fishing trip.”
European Food Safety Authority (EFSA), commenting on a previous Seralini study, said:
“Following a detailed statistical review and analysis by an EFSA Task Force, EFSA’s GMO Panel has concluded that this re-analysis of the data does not raise any new safety concerns.” EFSA noted that “The statistical analysis made by the authors of the paper did not take into account certain important statistical considerations. The assumptions underlying the statistical methodology employed by the authors led to misleading results. EFSA considers that the paper does not present a sound scientific justification in order to question the safety of (the) maize.”
Prof. David Spiegelhalter, Winton Professor of the Public Understanding of Risk, University Of Cambridge, gave this statement to the media:
“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.
“All the comparisons are made with the ‘untreated’ control group, which only comprised 10 rats of each sex, the majority of which also developed tumors. Superficially they appear to have performed better than most of the treated groups (although the highest dose GMO and Roundup male groups also fared well), but there is no proper statistical analysis, and the numbers are so low they do not amount to substantial evidence. I would be unwilling to accept these results unless they were replicated properly.” Read more.
