The study, led by Gilles-Eric Seralini of the University of Caen, concluded that rats given a diet of a corn variety that is highly resistant to the weedkiller Roundup, developed more tumors and died sooner than those on a regular diet. Female rats in particular were plagued with mammary tumors and died at rate that was 70 percent higher than the control group. The French government has asked its health department to look into the findings to see if GM corn could have similar effects on humans.
However, many other scientists — including those who don't work for Monsanto — have attacked the study's methodology, accusing the Caen team of going on a "statistical fishing trip." There are complaints that there isn't enough data on the rats' actual diet; that the sample size was too small; and that the rats in question are "very prone to mammary tumors particularly when food intake is not restricted." The statistical methods are called "unconventional" and "inadequate" and others suggested that the whole study was rigged because some of the rats were given Roundup in their water, instead of just eating the corn that was exposed to the pesticide.
The safety of GM foods is highly controversial, particularly in Europe where Monsanto has faced heavy opposition to its engineered crops and research on both sides of the debate has been accused of being highly politicized. However, GM corn and soybeans have been a major part of the U.S. diet for more than a decade and even scientists who support more and better labeling of GM crops says this particular study is highly flawed. If this study proves only one thing, it's that this fight isn't close to being over.