North Americans have been eating genetically modified food for many years with no discernable health problems. However, a new French study associates genetically modified organisms (GMO) with cancer in rats. The French government reacted with alarm, but the scientific community expressed nearly universal skepticism of the study, based on its methods and source of funding.
Fodder for anti-GMO movement?
The study, by French scientists published in the peer-reviewed journal Food and Chemical Toxicology, made headlines by concluding that rats fed a diet of genetically modified corn and trace amounts of the herbicide Roundup developed tumors and died sooner than a control group eating regular corn and no herbicides. Anti-GMO groups calling for a ban on genetically modified crops are citing the study. The French government is launching a probe to investigate the findings.
Rats not Roundup-ready
Researchers at Caen University, funded by the Committee of Research and Independent Information on Genetic Engineering (CRII-GEN), a French anti-GMO group, fed rats a genetically modified corn produced by the notorious U.S. agrichemical giant Monsanto. Monsanto genetically engineered the corn to survive treatment with its flagship herbicide, Roundup. Farmers can spray fields of “Roundup-ready” corn to kill weeds without affecting the crop.
Researchers also put traces of Roundup into the rats’ drinking water. While most studies are conducted for 90 days, this trial lasted two years, the standard lifetime of the average rat. Tumors developed earlier in the rats fed Roundup-ready corn and traces of the herbicide considered safe for drinking water in the U.S. Fifty percent of males and 70 percent of females died prematurely, compared with 30 percent and 20 percent respectively, in the control group.
A litany of fatal flaws
Lead author Gilles-Eric Seralini, an anti-GMO activist for 15 years, says the study provides solid evidence that humans shouldn’t be eating GMO foods. But his methods sparked a torrent of criticism. In particular, using the albino Sprague-Dawley rat, a strain of rodent prone to tumors.
Independent scientists also criticized the small size of the control group, arguing that only 20 rats in the control precluded a significant result. The study also raised the question of whether a diet based on corn is normal for rats. Plus, a perceived lack of objectivity was cited in the way some of the results were presented, such as showing pictures of rats with large tumors, without including pictures of rats in the control group.
Seralini’s history of sponsorship for anti-GMO claims has led critics to question his scientific credibility. More than 100 studies conducted by reputable scientists on GMO foods, published in peer-reviewed journals, have found no affect on health.
A massive human experiment
Mark Tester, a research professor at the Australian Centre for Plant Functional Genomics, University of Adelaide, said, “If the effects are as big as purported and if the work really is relevant to humans, why aren’t the North Americans dropping like flies?”
Tester has a point. A massive experiment on humans has been in progress since 1994 when Calgene began selling its genetically modified Flavr Savr tomato. Hundreds of millions of people in North America have been eating GMO food, primarily in the form of soybeans, corn, canola, rice and cottonseed oil. No evidence has emerged that these crops are harmful to human health.