Foes of Modified Corn Find Support in a Study
By Andrew Pollack, NY Times, September 19, 2012
Rats fed either genetically engineered corn or the herbicide Roundup had an increased risk of developing tumors, suffering organ damage and dying prematurely, according to a new study that was immediately swept up into the furor surrounding crop biotechnology when it was released Wednesday.
The study, conducted by a prominent opponent of genetically engineered crops, was immediately criticized by some other scientists, who said the methods were flawed and that other research had not found similar problems.
But in California, proponents of a ballot measure that would require genetically modified foods to be labeled immediately seized on the study as support for their cause. The French government ordered a review of the findings, saying they could possibly result in the suspension of European imports of that type of corn.
The study, which is being published in the peer-reviewed journal Food and Chemical Toxicology, was led by Gilles-Eric Séralini at the University of Caen in France. He is also a leader of the Committee for Independent Research and Information on Genetic Engineering, which sponsored the research.
The study followed 200 rats for two years, essentially their entire lives, far longer than the typical 90-day feeding studies used to win regulatory approval of genetically engineered crops in some countries. While there have been some other long-term studies, none has involved as many animals or as many detailed measurements.
“The results were really alarming,” Dr. Séralini said in a telephone news conference conducted by an organization in Britain opposed to genetically modified crops. He said that the tumors did not develop until well after 90 days, meaning they might have been missed by shorter studies.
The rats in the study were split into 10 groups, each containing 10 male and 10 female rats. Six of the groups were fed different amounts of a corn developed by Monsanto to be resistant to the herbicide Roundup. In some cases the corn had been sprayed in the field with Roundup.
Three other groups were given different doses of Roundup in their drinking water, with the lowest dose corresponding to what might be found in tap water in the United States, the authors said.
The 10th group, the control, was fed nonengineered corn and plain water.
The study found that in groups that ate the engineered corn, up to 50 percent of the males and 70 percent of the females died before they would have from normal aging, compared with 30 percent of the males and 20 percent of the females in the control group.
Some 50 to 80 percent of the female rats developed tumors compared with only 30 percent of the controls. And there were several times as many cases of liver and kidney injury in the exposed rats.
Some critics pointed out that the new findings contradicted other studies. One review of long-term studies, published earlier this year, concluded that those studies did not present evidence of health hazards.
Dr. Chassy said that people and livestock had been eating genetically modified grains for years without evidence of the high death rates and tumors in the study. “Curious that no increase in tumor incidence has been reported in animals eating large amounts of such grains,” he said.
Monsanto, in a statement, said it would review the study, but that other studies had confirmed the safety of its crops.