Is Genetically Modified Corn Toxic?

By Michael Reilly | Sat Jan 23, 2010 07:13 PM ET

In the United States, we grow and eat corn whose genes have been tweaked to make the plants more resistant to pests and pesticides. Most European countries don't, largely because the citizenry fears it isn't safe. But try as scientists might, they haven't been able to find any good reason why we shouldn't eat genetically modified (GM) food.
Until now. Maybe. A new analysis of data released by Monsanto pried from Monsanto's lawyers' cold dead hands by a tag-team of legal experts at Greenpeace and other groups suggests there may be something to the idea that we shouldn't be eating maize that's had its DNA messed with.
The study found that three strains of modded crops -- MON 810 and MON 863, which are resistant to pests, and NK 603, which is foritified to withstand weed killer -- significantly disrupted the blood chemistry of rats who ate them. According to an article in New Scientist:

With each of the three strains of maize, researchers say they found unusual concentrations of hormones and other compounds in the blood and urine of the tested rats, suggesting each strain impaired kidney and liver function. By the end of the trials, the female rats that were fed MON 863 had elevated blood-sugar levels and raised concentrations of fatty substances called triglycerides. Both are potential precursors of diabetes, according to [lead author Gilles-Eric Séralini of the University of Caen in France].

...

"What we've shown is clearly not proof of toxicity, but signs of toxicity," says Seralini. "I'm sure there's no acute toxicity, but who's to say there are no chronic effects?"

The researchers are suggesting that if the GM corn has the same affect in humans that is does in rats, we're unknowingly taxing our kidneys and livers, and probably raising the risk of damaging those organs.
But as is often the case in these type of reports, the conclusions aren't terribly convincing. For one, the effects are barely statistically significant, and the article goes on to say that independent toxicologists who saw the paper said Seralini was reading too much into the results.
So we're left with ambiguity. Terrific.
There's just one thing I want to know: why do activist groups have to team up to force Monsanto to release tests showing whether or not GM food is toxic? Shouldn't food have to be demonstrably NON-poisonous before anyone is allow to start feeding it to people??
Source: New Scientist
Image: Texas A&M University