About a month ago, an article appeared in my Facebook newsfeed about a new study claiming to have proof that genetically modified (GM) foods cause cancer in rats. At the time, I couldn't read the article but made a mental note to go back and review it. And then, as usual, life happened (which includes the care of feeding of my three very young childen).  Naturally, I forgot.  But today, Real Clear Science links to a must read article by Danish environmental writer Bjørn Lomborg, an adjunct professor at the Copenhagen Business School and founder of the Copenhagen Consensus Center.

The study claiming GM food is deadly was conducted by French researcher Gilles-Eric Séralini who fed rats GM corn for two years. The study then claims (and showed with the use of a terrifying video showing creepy lab workers holding up cancer ridden white rats) that the GM food caused huge tumors and early death in 200 rats. As Lomborg reports, without questoning or really analyzing the study, France’s health, ecology, and agriculture ministers threatened to ban imports of Monsanto’s GM corn to the European Union and Russia actually blocked imports of Monsanto corn.

Now, a month later and after the job of scaring the wits out of people about GM food has been completed, real analysis is being done of the Seralini study and it looks like this latest study on GM foods is just another pile of scary pictures.  Lomborg explains a number of problems with the study:

But Séralini’s research posed many problematic issues. For starters, the Sprague-Dawley strain of rats that he used is naturally prone to tumors. Studies of Sprague-Dawley rats show that 88-96% of those that serve as experimental controls develop tumors before they reach two years of age. But the public saw only pictures of tumorous rats that had consumed GM corn and Roundup. If the public had seen the similarly grotesque tumors that grow on untreated rats, officials most likely would not have acted so hastily.

Séralini used only 20 rats as a control group to be fed ordinary corn with no Roundup. Of these, five died within two years, which is unusual, because studies of thousands of untreated Sprague-Dawley rats show that about half should have died in that period. Using his low death rate as a base, Séralini claimed – with no statistical analysis – that the higher death rate (just below 40%) for the remaining 180 rats fed with GM corn and Roundup was suspicious.

Moreover, Séralini’s results contradict the latest meta-study of 24 long-term studies (up to two years and five generations), which found that the data do “not suggest any health hazards” and display “no statistically significant differences” between GM and conventional food.

Oddly, Séralini permitted access to his paper to only a select group of reporters, and demanded that they sign a confidentiality agreement preventing them from interviewing other experts about the research before publication. But, while the first round of articles read like press releases, the scientific community has since spoken out forcefully. The European Food Safety Authority, for example, has now concluded that the “design, reporting, and analysis of the study, as outlined in the paper, are inadequate.”

The study was partly funded by CRIIGEN, a group that campaigns against biotechnology. CRIIGEN’s scientific board is headed by none other than Séralini, who has also just released a book (in French) and a documentary film decrying GM food.

Why does debunking these studies matter? Lomberg addresses that as well, saying:

This debacle matters because many GM crops provide tangible benefits for people and the environment. They enable farmers to produce higher yields with fewer inputs (such as pesticides), so that more food can be produced from existing farmland. That, in turn, implies less human encroachment into natural ecosystems, enabling greater biodiversity. But, of course, Séralini’s pictures of cancer-addled rats munching GM corn have instead been burned into the public imagination.