Rats Eating GMO Corn Get Tumors, Die Early

Rats fed genetically modified corn or exposed to the Monsanto herbicide Roundup were at greater risk for developing tumors, suffering organ damage or dying prematurely according to a just-published study in the journal Food and Chemical Toxicology. 200 rats were tested for two years (more or less their lifespan), much longer than the 90 days required for studies that are used when companies seek regulatory approval for genetically engineered foods. “The results were really alarming,” the study’s author, Gilles-Eric Seralini of the University of Caen in France, said.

The French site, Rue89, has photos of the rats with tumors that, it would be an understatement to say, are very disturbing.

Immediate Controversy About Rats and GMO Corn Study

The study‘s results, announced at a news conference organized by a British-based anti-GMO organization, immediately stoked criticism of Seralini’s methods and comments about his campaigning against GMOs since 1997, NPR notes. Bruce M. Chassy, professor emeritus of food science at the University of Illinois, told the New York Times that Seralini’s study is “not innocent” but rather “a well-planned and cleverly orchestrated media event.” Indeed, Seralini’s earlier research has also been questioned for using statistical methods that “led to misleading results.”

But others, including those supporting a California ballot measure, Proposition 37, to require that GMO foods be labeled and the French government, heralded the study‘s findings. France bans growing GMO crops and might suspend European imports of genetically engineered corn.

200 Rats Studied For Two Years

The study involved 200 rats split into ten groups (with ten male and ten female rats per group). Six groups were fed varying amounts of corn that Monsanto has genetically modified to be resistant to its best-selling weedkiller, Roundup. Three other groups were given Roundup in varying amounts in their drinking water. A tenth group was the control and given nonengineered corn and plain water.

Of the rats who ate the GMO corn, up to 50 percent of the males and 70 percent of the females in the different groups died prematurely, compared with 30 percent of the males and 20 percent of the females in the control group. In addition, says the New York Times, ”some 50 to 80 percent of the female rats [in the different groups] developed tumors compared with only 30 percent” of those in the control group. Rats exposed to GM corn or Roundup also had several times as many cases of liver and kidney injury as the control group.

Some scientists pointed out that the types of experimental rats used in the study are prone to tumors, says NPR. David Spiegelhalter, a professor at the University of Cambridge whose specialty is the public perception of risk, said in the New York Times that the “numbers of animals in each group was too low to draw firm conclusions.”

In addition, other scientists pointed out that the rats who ate a diet with a GMO concentration of 11 percent were less healthy than those whose diet contained a GMO concentration of 33 percent: if the experiment intended to show a link between developing tumors and GMOs, those who ate more GMOs should have been less healthy.

In Reuters, Mark Tester, a research professor at the Australian Centre for Plant Functional Genomics at the University of Adelaide, observed that, since genetically modified food has “been in the food chain” in the U.S. for over ten years, “If the effects [of Seralini's study] are as big as purported, and if the work really is relevant to humans, why aren’t the North Americans dropping like flies?”

Food Fights Over Organics and GMOs

Seralini’s study is unleashing as much disagreement as the Stanford University study that found that organics are no more nutritious than conventional ones. Some scientists, regarding the Stanford study, remind us to keep ourselves focused not on the particularities, errors, etc. of one individual study but on the bigger picture.

The Pump Handle at Science Blogs points out that, besides the headline-making claim about organic foods not being more nutritious, the Stanford study also found that organic foods contain 30 percent fewer pesticide residues. Recent work by researchers at the Columbia University Mailman School of Public Health has indeed discovered a “strong association between prenatal pesticide exposure and adverse impacts on behavior, brain structure, cognitive ability, and neurodevelopment.”

Even more, Casaubon’s Book, also at Science Blogs, reminds us that “the reality is that organics started because of concern about the larger environment, not to make your food extra nutritious.” Organics aren’t only about making a healthier tomato, but about figuring out how might we produce food using sustainable methods that are far more friendly for the environment, that don’t require burning fossil fuels.

Maybe North Americans aren’t “dropping like flies” despite eating GMO corn for over ten years. Maybe it would have been better if Seralini had presented his study‘s results with less fanfare.

But it’s not just that “Roundup Ready” corn is not what nature gave us. Farmers who use the corn must buy new seeds (from Monsanto) every year and use plenty of Roundup (made by Monsanto) to keep their fields weed-free. As the Union of Concerned Scientists points out, wouldn’t it be better for the collective health of ourselves and our planet not to keep buying Monsanto’s products, but to grow our food in ways that minimize environmental pollution?

Related Care2 Coverage

Yes, Organics are Better for You: New Study Misses the Mark

Critics Raise Alarms Over Stanford Organics Study

Monsanto Threatens To Sue Vermont If GMO Labeling Bill Passes


Jim Ven
Jim V2 years ago

thanks for sharing.

Sarah M.
Sarah M6 years ago

Love the final rhetorical question!

Stanley Rampersad
Stanley Balgobin6 years ago

Shut down Monsanto now !!! Arrest all the CEO's and fine them $100 million Make a felony enforceable law for any sale of GM foods. Petition,. demonstrate for the health and lives of our children and seniors. Imprison the profiteers, the greedy elites who poison our food supply. Outlaw the neo-con right wing repugliscum fascists. Waterboard the Corporate vampires, the wall street vultures, the CEo banking crooks. Raise the minimum wage to $20/hr; the maximum income by law to $100,000/yr. Free Universal Health care, free University Education for our children. We are the 99%, the evil 1% are criminals who parasite off our blood, sweat, tears. Bring back Democracy to America, decency, honor, economic equality, air play, and social justice.

Malgorzata Zmuda
Malgorzata Zmuda6 years ago

Nie powinno się torturować żywnością GMO ani zwierząt ani ludzi.

Elena T.
Elena Poensgen6 years ago

Very interesting, thanks.

Mit Wes
Mit Wes6 years ago

Cyrlle D., As a French women, is this the kind of scientific work the French want to be known for considering how this study was conducted ?

Cyrille D.
Cyrille D6 years ago

So scary. I'm French and heard about this research on the radio. I'm happy we don't have GMOs on our market here. But, having an American boyfriend, I'm worried for him and for what I'll eat when I'm in the US from now on ! You never truly know...

Dan B.
Dan Brook6 years ago

If we can't ban 'em, at least label 'em!

Vote YES on Prop 37 in CA

Ajla C.
Past Member 6 years ago

Stare vijesti.

Heather M
Heather Marv6 years ago

When Society or an organisation/s mess with the natural food of course there are going to be problems for everybody concerned even the rats.