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Marcia Ishii

First ever long-term study on GE food health effects

Very big news exploding across the papers yesterday. Eating genetically engineered (GE) corn has been strongly linked to serious health effects — including mammary tumors, kidney and liver damage. A team of European scientists yesterday released the first independent long-term animal feeding study of its kind on the health effects of eating GE foods in the peer-reviewed journal Food and Chemical Toxicology. 

How and why we can find ourselves 15 years into the commercialization of GE crops without a comprehensive set of independent long-term animal health impact studies is the story beneath this story. I'll get to that in a minute.

Meanwhile, news of the study has gained global currency and already France has called for a probe that could lead to European Union intervention including emergency suspension of imports of the GE corn, a Monsanto product. Back at home, the findings take on particular relevance as California voters consider the Proposition 37 “Right to Know” initiative to label GE foods and as USDA considers approving a new wave of GE crops, starting with 2,4-D corn.

What the study says

In a nutshell, the scientists — led by University of Caen molecular biologist Gilles-Eric Séralini — tested the long-term health effects of feeding rats diets consisting of different percentages of Monsanto’s RoundUp-Ready corn, both from fields treated and not treated with the herbicide RoundUp. They also tested the effects of RoundUp alone by comparing the health of rats fed a conventional (non-GE) corn diet with and without RoundUp added to their water, at the levels that have been found in tapwater or in GE feed.

The researchers found that rats fed GE corn and those whose water contained environmentally relevant levels of the herbicide RoundUp faced the following:

  • 2 to 3 times more large tumors than the control group; 
  • Females developed mammary and pituitary gland tumors, suffered pituitary gland abnormalities and hormone disruption;
  • Male rats also developed tumors, but in particular experienced serious kidney and liver damage; 
  • 50% of males and 70% of females died prematurely compared to 30% and 20% respectively in the control groups.

And the effects grew over time, so that by the beginning of the second year of the study, 50-80% of females in all treated groups (with and without Roundup contamination) had developed large tumors versus only 30% of the control group.

Why haven’t we heard of these kinds of results before? To date we’ve only had a handful of short-term lab studies, mostly conducted by  industry and almost none stretching longer than 90 days, the equivalent of adolescence in the study animals. The kinds of tumors and organ damage found by the European scientists take a bit more time to develop.

No single study can be definitive, but what Séralini's work points to is the need to take very seriously, and more rigorously understand, the risks to human health posed by GE crops and foods.

Who knew?

It is rather bizarre and problematic that no U.S. government agency has required independent long-term health studies before releasing these [GE] organisms into the environment. It is unbelievable that in the U.S. only industry conducts the tests.

— Gilles-Eric Séralini, University of Caen, France

And here’s the bigger news story: why is this the first independent, peer-reviewed, long-term health study of its kind on the effects of eating GE foods, despite their presence in our food supply for 15 years?

Unfortunately, independent research in the U.S. into the health effects of GE foods before they are released into our food supply has been virtually impossible. The "Big 6" pesticide and biotech companies that manufacture and tightly control patents on GE products have suppressed and restricted research into the efficacy and health impacts of their products. Licensing agreements expressly forbid research unless it has been approved by the patent-holders, and they retain and exercise the right to prevent publication when results are not as desired.

Scientists have been complaining about this state of affairs since at least 1999. More recently in 2010, a Scientific American editorial again noted both the lack of access and suppression of research.

Industry repeatedly insists that their GE products are safe, but they do so on the basis of studies that have never been repeated and have been criticized by independent scientists as deeply flawed. Repeating a talking point is not the same thing as repeating a study.

Meanwhile, contrary to popular belief, U.S. regulators at the Food and Drug Administration do not require independent studies verifying safety before approving the release of these products into our food supply.

The Séralini study will draw predictable opposition from Dow and Monsanto as these companies rush new GE crops like 2,4-D-resistant corn to market. And who knows how long this particular news cycle will take to play out.

I can only hope that the shockwaves generated by this study will wake up the regulators in our public agencies who have been willfully asleep at the switch for 15 years now. In the meantime (since said regulators seem to be clinging fast to their pillows), it appears to be up to Americans to assert our right to know what’s in our food and to choose for ourselves whether to eat genetically engineered products or not. This fundamental right to know will be at the ballot box in November when Californians have the opportunity to vote for Proposition 37 and demand labeling of genetically engineered foods.

Learn more » Read PAN's position on Proposition 37, see our summary of existing research on health and environmental impacts of genetically engineered foods and check out the fully referenced synthesis by independent scientists here.

Editor's Note: It has come to our attention that a few other long-term studies of GE foods have been published in the past, although the French study remains the most in-depth long-term feeding trial investigating the lifetime health effects of eating a GE-based diet. It is also the only such study examining this particular widely-consumed GE corn (NK603) that has been peer reviewed and published, and is also the only one to have experimentally differentiated between the effects of consuming the GE corn itself and the herbicide (Roundup) with which it is intended to be used (and which as a result, can contaminate water or the corn itself in the form of residues). 

This blog was originally posted on Maria's Farm Country Kitchen and Huffington Post.

Picture of Marcia Ishii

Marcia Ishii

Marcia Ishii is director of PAN’s Grassroots Science Program and a Senior Scientist with a background in insect ecology and pest management. Her campaign work focuses on supporting and strengthening agroecology movements and policies in the U.S. and globally, in addition to challenging corporate control of our food and seed systems. Follow @MarciaIshii

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