GE Foods Shorten Life, Cause Tumors
Says First-Ever Long-Term Study

by Marcia Ishii-Eiteman, senior scientist at Pesticide Action Network

Very big news exploded across the papers yesterday: Eating genetically engineered (GE) corn has been strongly linked to serious health effects—including mammary tumors and kidney and liver damage. A team of European scientists released the first-ever long-term animal feeding study of 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 single long-term, animal health impact study until now 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 in question, 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 U.S. Department of Agriculture 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 the addition of RoundUp to their water, at levels that have been found in tap water or in GE feed.

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

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

And the effects grew over time, so that by the beginning of the second year of the study, 50 to 80 percent of the females in all treated groups had developed large tumors, versus only 30 percent 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, 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?

Here’s the bigger news story: Why is this the first long-term health study on the effects of eating GE foods ever to have taken place, despite their presence in our food supply for 15 years?

Unfortunately, independent research into the health effects of GE foods before they are released into our food supply has been virtually impossible in the U.S. 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 the suppression of research.

Industry players repeatedly insist that their GE products are safe, but they do so on the basis of studies that have never been repeated and ones that independent scientists have criticized as being 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.

At present, many of the foods we eat and feed our children—up to 80 percent of the products on grocery store shelves—include genetically engineered ingredients. But without a label, the only sure way to know our food is GE-free is if it’s certified organic.  Pesticide and GE seed corporations like Monsanto want to keep us in the dark to maintain unfettered, unlabeled access to the market. But we have a right to know what we’re eating! Help us fight for the right to know:

Learn more

To read Pesticide Action Network’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.


Marcia Ishii-Eiteman is a senior scientist and director of the Sustainable Food Systems Program at Pesticide Action Network (PAN). Marcia holds a PhD in ecology and evolutionary biology from Cornell University. She has written extensively on the ecological, social, and political dimensions of food and agriculture, and was a lead author of the UN-sponsored International Assessment of Agricultural Knowledge, Science and Technology for Development.


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9 Responses to GE Foods Shorten Life, Cause Tumors
Says First-Ever Long-Term Study

  1. Jen Lueders September 20, 2012 at 11:22 pm #

    Thabks so much for the article about the pesticides causing
    Pituitary tumors. As I sit here with a pituitary tumor in my
    Head I was hoping you might have an idea of how we can deal
    With these tumors. As of right now I’m looking at meds for the
    Rest of my life or surgery. If you have found a natural way to
    Detox or naturally remove it please share. An herbalist told me to
    Take digestive enzymes one to two hours before I eat and it should weaken the wall of the tumor and let my body naturally
    Flush it out. Probably is the digestive enzymes hurt my stomach. Thanks again for the info. The FDA need to be held accountable for such decisions. I realize they have limited funds, as does every agency but it’s our health. We are worth it.

  2. Patty September 26, 2012 at 10:48 am #

    I would really appreciate it if these articles had a link to post directly to facebook. Thank you so much for the Tweeter link….I posted it there. This article really needs to be shared with as many people as possible.

  3. Patty September 26, 2012 at 10:49 am #

    ok weird, after I wrote this, it just showed up! Nothing like manifesting the button!! LOL

  4. Nancy September 26, 2012 at 10:53 am #

    Jen i would contact Dr robert Morse in florida. he has a great detox/cleanse program that has helped many who choose the Natural Path for healing.

  5. Judy Persin September 28, 2012 at 6:08 pm #

    To Jen Leuders:
    Dear Jen, I have taken digestive enzymes for inflammation and I know about the ability they have to dissolve the membrane of tumors. I have taken GDU from for inflammation. I have taken a lot, but it has never hurt my stomach. It did make a lump on the inside of my mouth disappear. It was like a small tumor. However, you could try POLY-MVA. I have taken it myself to wipe out systemic candida albicans which I do think is often the culprit involved in cancer. It is an amazing product. No side effects unless you take too much too fast and cause cancer cells to die too quickly, giving you a toxic load which can cause headaches and flu-like symptoms. POLY -MVA is a liquid, and not unpleasant to take. You take no more than a tsp in a half (or less) glass of water. It is a mighty immune system booster. You can go to to learn more and to buy POLY-MVA. Also go to and click onto the audios on the upper right-hand side of the home page. Listen to the top one first. Also, copy this address and check it out. A few tips: 1. Oxygen destroys cancer. Why are they not using the hyperbaric oxygen chamber that is used for divers? 2. Cancer cannot live in an alkaline environment. Learn what foods are alkaline and make them your diet. Squeeze pure lemon juice into you water and drink between meals. Although lemons are acidic–they make your body alkaline. 3. Cancer feeds on sugar–especially high fructose corn syrup. Avoid it like the plague! Eat only organic foods if possible. If I can be of any encouragement, Jen, email me at Please put ” Jen L.” in the subject line so I will not overlook your email. Good health to you! Judy
    PS: the FDA as well as the EPA and the USDA are infiltrated by Monsanto people and they have no allegiance to our citizens, but only to the big chemical companies who are poisoning us. The FDA, EPA, and our USDA have actually become our enemies!

  6. Kathy September 29, 2012 at 5:07 am #

    I live in a college town where the big corps concerning farming are huge contributors to the college. You will find very few people here who will even listen much less demand to know what is in our food. They support the corps who give them money, end of story. The only reason we have organics at all is because of the students wanting them. Because of the extreme negative attitude towards questioning the corporations responsible for poisoning our foods, drinks, water, etc. I have decide to move to an area where they are more open to the truth. Believe me after seven years of trying I have not made much of a dent with people here because the companies in question are considered saints for donating so much money. Here money is more important than health.

  7. Laurella September 29, 2012 at 11:08 pm #

    Even the respected journal, Scientific American, published an article by the editors indicating that research on GMO foods needed to be done but was IMPOSSIBLE in the US due to federal regulations that had been put in place which protected the companies producing these products from having to provide the GMO items to researchers. So, it was impossible for any legitimate respected scientific entity in the US to do the necessary work and get it published. Thanks for this great article. It is needed.

  8. Jen L March 30, 2013 at 9:59 pm #

    Hi! Thank you all for responding! I am just so sorry it took me this long to get back on here. I had thyroid surgery and tiring of dealing with my various auto immune disorders, I have also been dealing with a rare form of sleep apnea. Soooo just wanted to let you know about my progress! I still have the 1 inch tumor but am taking digestive enzmes for it and getting ready to start juicing ALOT! Check out Gerson Diet and tell me what you think. You can also find me on face book. I started a new auto immune group on there and I am pretty much plugged into numerous groups on there. I have become a reader of labels and have learned so much. Blessings, Jen

  9. Guadalupe April 8, 2014 at 3:55 pm #

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