GM Study Reveals Health Damage and Cover-up

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October 16, 2007 | 9,716 views

The following article describes a study revealing health problems associated with a genetically modified corn and the attempts by Monsanto and European regulators to distort the findings. As this longer-than-normal column provides in-depth analysis of a current newsworthy controversy, please pass this article on to reporters who can freely reprint in whole or in part, or use it as background material.

GM Study Reveals Health Damage and Cover-up

By Jeffrey M. Smith, author of Seeds of Deception

A German court ordered Monsanto to make public a controversial 90-day rat study on June 20, 2005. The data upheld claims by prominent scientists that animals fed genetically modified (GM) corn developed extensive health effects in the blood, kidneys, and liver ... and that humans eating the corn might also be at risk.

The 1,139 page research paper on Monsanto‘s "Mon 863" variety also showed that European regulators accepted the company‘s assurances that their corn is safe, despite unscientific and contradictory rationale used to dismiss major problems. Also, the study is so full of flaws and omissions that critics say it would not qualify for publication in most journals. Yet it is the primary document used to evaluate the health impacts.

Mon 863 is genetically engineered to produce its own pesticide, a toxin called Bacillus thuringiensis or Bt, which is designed to attack a corn pest called the corn rootworm.

Rats fed Mon 863 developed several reactions:

Top research biologist Arpad Pusztai, commissioned by the German government to evaluate the study in 2004, determined that no one can say that Mon 863 will cause cancer, allergies, or anything specific based on the evidence. The results are preliminary and must be followed-up to rule these out. He warns, however, "It is almost impossible to imagine that major lesions in important organs... or changes in blood parameters... that occurred in GM maize-fed rats, is incidental and due to simple biological variability."

French Professor Gilles-Eric Seralini, molecular endocrinologist at the University of Caen, agrees that the results show a toxic reaction. Seralini is a member of two French government commissions evaluating GM food. One of those commissions rejected a request for approval of the corn variety in October, 2003 due to adverse findings of the study. Seralini won a French lawsuit allowing him to express his concerns in public. Later Greenpeace won a German court battle that makes public the data he was concerned about.

Pusztai and Seralini spoke about the Mon 863 study at a June 22 press conference in Berlin organized by Greenpeace. Both scientists are uniquely qualified to evaluate the study.

Seralini studies endocrine disruptors and the impact of pesticides on health. He was one of four experts appointed to respond to the WTO challenge filed by the US against the European Union‘s policy on GM food and crops. He reads all of the industry‘s GM-food submissions to Europe and all the commentaries on the submissions.

Pusztai, a leading authority in his field of protein science (lectins), was commissioned by the UK government in the 1990s to develop the ideal testing protocol for all GM foods. His protocol was set to be adopted by the UK government and eventually in Europe. But his controversial finding that GM potatoes damaged the health of rats stopped the work. Pusztai had been commissioned to evaluate all published studies on GM foods. He also analyzed most of the confidential submissions made by industry.

Both these scientists expressed alarm about the unsupported arguments that Monsanto and some European regulators use to force product approvals. Now that the Mon 863 study is available, other scientists and the public can evaluate the industry‘s defense, which Pusztai and Seralini say contradict well established scientific principles. Chief among their concerns are the ways Monsanto explains away statistically significant effects.

CLICK HERE to become involved in the push for more honesty in research used to determine your food quality.

Problems Disguised as Non-Problems

In animal feeding studies, researchers attempt to minimize differences between the test animals and the control groups so that only the impact of the item being analyzed stands out. In this study, test rats ate Mon 863 and the control group ate non-GM corn from the same parent line. In other words, the corn had the same genetics except for the insertion of the genetic material and its impact.

Comparing the results of these two groups, health impacts were well-defined and occurred at a rate that the scientific community accepts as not due to chance. But Monsanto and their supporters in the European Food Safety Authority (EFSA) appear to throw away accepted methods of science that have been used for decades, in order to rationalize the findings.

1. Researchers used six additional control groups, which were fed commercial corn varieties with entirely different genetics. Such comparisons are appropriate for commercial studies. But it is entirely inappropriate for a safety assessment, according to Pusztai.

Monsanto claimed that when changes in the test rats were compared to this much larger, irrelevant control group, many changes were no longer significant.

2. Despite the strained logic, many results were still statistically significant when compared to these six other controls. They were even reported as such by the laboratory that Monsanto used to conduct the study.

Monsanto ignored the study‘s figures and claimed that since changes in the rats were still within a wide range of reactions considered normal for animals, they should be treated as biologically irrelevant. Using this argument, they declared that a 52% decrease in reticulocytes (immature red blood cells) was "attributable to normal biological variability."

According to Pusztai, an allowance of 5% variability is the norm in food experiments. Similarly, he says that the increase in blood sugar levels by 10% "cannot be written off as biologically insignificant, given the epidemic of diabetes."

3. In spite of the statistical slight-of-hand, several results could not be dismissed, since they were well beyond the range Monsanto defined as normal. So the company claimed that the potentially dangerous health effects were insignificant because the reaction among the rats was not consistent between males and females. "This is really ridiculous," says Seralini, because everyone studying cancer and endocrinology knows that there are differences between genders.

4. When even the gender defense could not be applied to a particular finding, Monsanto dismissed it because the reactions were not always dose specific.

Specifically, the results observed in rats fed a diet of 11% Mon 863 were sometimes more pronounced than results found in rats fed a 33% diet. Seralini notes that in endocrinology and toxicology research, differences are not always proportional to effects noted. A small dose of a hormone, for example, can cause a woman to ovulate, while a larger dose can make her infertile.

5. When all other excuses failed, Monsanto claimed that with such a large study, one would expect lots of results to fall in the statistically significant category purely by chance. Thus, no follow-up is required.

Seralini says, "It is dishonest not to do the tests again if you have statistical significance." Pusztai similarly asks, "What is the point of doing a study if you dismiss the results you find?" He insists that you design a study specifically so that statistical significance indicates biological significance.

CLICK HERE to push for public disclosure of industry research studies.

In spite of the fact that Monsanto‘s explanations were at odds with time-honored principles of science, the European Food Standards Agency (EFSA) recommended that Mon 863 be approved. In fact, the agency‘s justification mimics that of Monsanto, point for point.

Although EFSA recommended approval of Mon 863, the majority of the countries in the EU Council of Ministers voted not to approve the corn on July 24, 2005. But here‘s the glitch: EU law requires a "qualified majority" on such a vote. So the pro-GM European Commission is now authorized to make the decision and approve Mon 863 within a few months.

Mon 863 will not be the first approved GM food in Europe to have shown significant health effects in rats. Per Seralini, an oilseed rape (GT 73), Roundup Ready corn (NK 603), and two Bt corn varieties (Bt11 and Mon 810) all showed statistically significant problems that regulators did not pursue with follow-up research.

Seralini said that the effects of the GM crops were similar to that of pesticides, including inflammation disorders, and problems with livers and kidneys, two major organs involved with detoxification. Seralini is in a research group raising money to do independent research on a GM variety he says showed more than 50 significant rat anomalies.

GM‘s Unpredicted Effects -- How Can They Harm You?

How can a GM crop create so many significant unpredicted side effects? There are several ways.

The process of gene insertion typically results in hundreds or thousands of mutations throughout the genome. Insertion also changes the amount of protein that natural genes produce (5% of the genes in one study) and can destroy natural genes altogether.

The protein created by the inserted gene may also create allergies or toxins. Several studies indicate that the Bt toxin can cause allergic or immune system effects.

Furthermore, according to Monsanto‘s submission on Mon 863 to Australia and New Zealand, some of the foreign genetic material that was added into the corn was mutated during the insertion process. This means the composition of the Bt protein created by the corn is probably different than the one scientists intended.

With so many ways to create side effects, many scientists and consumer groups are demanding extensive evaluations and insist that a simple 90-day rat experiment is not competent to protect the public.

In the EU, pesticide approvals require research on three types of mammals, with feeding studies ranging from 90 days to two years. Seralini points out that Bt crops create new pesticides. Mon 863, for example, is unique. It differs from the natural version of Bt toxin in seven ways and should require at least the same level of evaluation as chemical pesticides, per Seralini.

The same holds true for herbicide tolerant crops that are engineered to survive large applications of weed killers such as Monsanto‘s Roundup. Seralini says that these GM plants have far more herbicide residues in the edible portions and recommends extensive toxicity tests.

CLICK HERE to help refute claims by the biotech industry that they cannot afford testing.

But the biotech industry claims that they cannot afford to introduce GM crops if they have to pay for the tests required for pesticides in Europe. GM crop approvals in the US cost even less. US authorities require only 30-day studies for Bt plants. No safety tests whatsoever are required for herbicide tolerant varieties.

Rigging the Tests to Obtain Industry‘s Desired Results

According to Pusztai, the quality of Monsanto‘s study was well below that normally required for a peer reviewed publication. He says, "It is odd, therefore, that it remains the central document considered by government regulatory authorities upon which to make a decision to protect the health of European citizens."

CLICK HERE to push to require the biotech industry to meet standards for peer reviewed publication.

Several features of the study appear to have been rigged to avoid finding problems.

Nutritional studies typically use young, fast-growing animals, which are sensitive to toxic and nutritional effects. By using a mix of young and old animals, Monsanto‘s research design can hide serious problems.

Similarly, they used rats with a huge range of starting weights. Pusztai states that the starting weights in a rat feeding study should not vary more than 2% from the average. By contrast, the male starting weights in Monsanto‘s study ranged from 198.4 to 259.8 grams (or 143 to 186 grams according to the conflicting data in the study‘s appendix). In either event, the wide range "can make it impossible to find significant differences in animal weights at the end of the experiment," according to Pusztai.

Monsanto tested the effects of two diets. One Mon 863 constituted 33% of the rats‘ diet. The other was 11%.

Even in the 33% group, GM corn protein comprised only about 15% of the rats‘ total protein. Pusztai believes that researchers should have started with the maximum amount of corn possible while maintaining a balanced diet, and then used lower concentrations to evaluate any dose effect.

Since rats are stand-ins for humans, it is worthy of note that African aid recipients typically rely on corn for 90% of their total caloric intake.

Researchers also supplemented the corn with a commercial animal feed. Although its composition wasn‘t reported, it may have contained GM soy, which could have skewed the results.

The study relied on analytical methods that are half a century old. It ignored powerful new methods, such as profiling techniques, DNA chips, proteomics, and others.

They relied on just two observation times (week 5 and week 14), which doesn‘t give data about the intervening periods. And the short 90-day time period will miss chronic and reproductive problems, and problems in the next generation.

The analysis of the findings was obscured by using six irrelevant control groups fed commercial diets, and data from historical databases. Such comparisons are totally unacceptable in the field of nutrition.

Pusztai said, "The study should have included a control group fed the non-GM parent line, spiked with the Bt" toxin obtained from the Mon 863. If GM-fed rats reacted worse than the ones fed this control diet, it would show that the genetic engineering process and its unpredictable side effects -- not the Bt toxin -- were responsible. According to Pusztai, "A second parental line spiked with a known toxin would also be useful as a positive control," to be sure the measurements are sensitive enough to detect the expected impact of the toxin. Without this, it is difficult to know if the methods were working properly.

Monsanto also defended changes in kidney weights by comparing the values with a separate study, which used different corn genetics and a different lab. As stated by Pusztai, this absurd inter-experimental comparison is never done and should be disregarded.

Some of the reported weight measurements were also bizarre, suggesting possible problems with animal management or faulty data. One rat dropped 53 grams in one week and gained 102 grams in the next. Some that were heaviest at the beginning of the experiment were the lightest at the end. And the rats hardly grew at all during the last four weeks.

Overall, the research paper was confusing, conflicting, and poorly reported.

Since these most basic requirements for a nutritional study were not provided, the research cannot be repeated and the results remain suspect.
Referring to the study as a whole, Pusztai said, "Nutritional scientists and leading journals would not accept these blatant inadequacies and misinterpretations."

Public Protection Falls to the Politics of Science

When Seralini wanted to voice his concerns about the industry‘s safety studies, he was told by French authorities that he was legally bound to keep even his opinions confidential.

A lawsuit eventually granted him the right to speak. But until June 20, 2005, biotech companies were able to keep their feeding studies hidden by claiming that they contained confidential business information. Seralini says that "No one can understand, even among EU regulators, why the composition of the blood of rats that have eaten the GM is secret."

The precedent established by the German court may open the door for more biotech studies to be made public. Without disclosure, says Seralini, just a few toxicologists can make the decision without public evaluation. And too often, the decision-making body is heavily influenced by the applying company.

In his French Commission for Biomolecular Genetics (CBG), for example, the government nominates three candidates for the position of the very important ‘external referee.‘ That referee studies the application and presents the relevant facts to the 18-member committee. For about ten years, the applicant companies such as Monsanto were able to choose which candidate of the three was to be the referee overseeing their products‘ approval process.

Seralini says, "I had a big fight with the commission" over the conflict of interest. As a result, the government changed the rules, and for the Mon 863 application they allowed the president of the commission the right to choose the referee. The president, however, is a geneticist who works very closely with industry. He appointed the same person that the biotech industry chose in the past.

After the CBG failed to approve Monsanto‘s corn in 2003, the president asked for an outside scientist to re-evaluate just one of the significant differences -- kidney weight. According to Seralini, the consultant ignored the blood and liver disorders entirely. And no additional research was actually conducted. The consultant simply re-examined the same data and declared the results insignificant.

The commission scheduled another vote, but failed to achieve a quorum. The president ruled that a quorum would not be needed in the next meeting, and only five members showed up. The president cast the deciding vote that approved Mon 863, 3 votes to 2. The other votes in favor came from the commission‘s vice-president, who works at an organization that conducts agricultural research, and a scientist.

Would you like to have impartial commissioners not related to the biotech industry? CLICK HERE to support efforts toward that goal.

According to Seralini, the scientist is a toxicologist who, oddly enough, is "‘always against long animal toxicity tests." In fact, he had been part of the French committee that approved Novartis (now Syngenta) E 176 corn after it had been tested for only two weeks with three cows. Actually, there were four cows at the start of the study, but one died and was removed.

That toxicologist is also on the European Food Standards Agency that endorsed Mon 863. EFSA has come under attack for including primarily pro-GM scientists.

According to a November 2004 report by Friends of the Earth, "One member has direct financial links with the biotech industry and others have indirect links... Two members have even appeared in promotional videos produced by the biotech industry." Several members, including the chairman, have been part of an EU-funded project with the stated goal to ‘facilitate market introduction of GMO‘s in Europe.‘

US Pushes Agenda and Pests on Europe

The United States government‘s support for biotech is no secret. In fact, it is the official policy in several US agencies to promote the industry, and some of them have attempted to push acceptance of GM crops in Europe.

In the case of Mon 863, it seems the corn is designed to solve a European problem that the US introduced. The corn is engineered with a pesticide to attack insects such as Diabrotica (corn rootworm).

According to Seralini, "Diabrotica is from a very dangerous family of insects for a wide range of crops and was absent from the European countries until the late 1990s, forbidden even in laboratories because it is very difficult to eliminate it with known chemical insecticides." He says it appears to have entered Europe from the US in large numbers during the Balkan war. Specifically, it was widespread around US military airports, whose planes were likely to have carried the pest. It has since spread to Italy, France, and Germany.

Seralini notes, "Monsanto seems to have anticipated this problem." Before any infestation had been discovered, they were already field testing their corn in France in the late 1990s. It takes about five years of local field trials for a GM variety to be accepted in an EU nation, so such early testing was necessary.

In addition to crop pests, Europe may have also imported the US tradition of approving GM products based on faulty studies. Documents stolen from the US FDA reveal that when Monsanto‘s researchers intended to illustrate that their GM bovine growth hormone did not interfere with cows‘ fertility, they allegedly added cows to the study that were pregnant prior to injection. An FDA whistle-blower also charged that sick cows were removed from industry studies altogether (see Seeds of Deception, chapter 3).

Independent Studies -- Not Industry Studies -- Needed

Critics demand that regulators use independent studies, not industry studies, to prevent data manipulation. But there are only a few independently funded researchers.

Biology professor Bela Darvas of Hungary‘s Debrecen University is one of them. After discovering that one of Monsanto‘s Bt corn varieties, Mon 810, is lethal to two Hungarian protected species and one insect classified as rare, he ran into unexpected obstacles. Now Monsanto refuses to give him any more Mon 810 corn to use in his tests. They also refused his request for Mon 863.

Perhaps with the court‘s release of Monsanto‘s rat study, the public will demand a more thorough investigation into GM foods, and a change in the review and approval process. Until then, Europeans are relatively safe from unintended effects because most manufacturers refuse to use even approved GM ingredients there, except animal feed. Meanwhile, consumers in the US will unwittingly serve as the guinea pigs.

CLICK HERE to help enact changes in the review and approval processof the GM maize.

Update As of March 15, 2007

Professor Seralini and a team of scientists decided to reevaluate the raw data from Monsanto‘s Mon 863 study using proper analytical techniques. They published their findings in the Archives of Environmental Contamination and Toxicology in March 2007. It demonstrated that the rats had clear signs of liver and kidney toxicity. The following it an excerpt of the press release.

A Serious Concern: Authorized GM Maize Unfit For Consumption

The case of Bt GM maize MON 863
Press release CRIIGEN -- March 2007


For the first time in the world, an independent study on the health risks of a GM maize authorized for consumption shows signs of hepatorenal toxicity (1). It is a counter-valuation performed by CRIIGEN (France), of a regulatory study by the Monsanto Company, on rats fed with a GM maize (MON 863) over a three-month period.

The raw data were used to obtain the commercial release of this GM maize at an international level. These revelations are certainly sufficient to require an immediate ban of GM maize MON 863 and all its hybrids from human or animal consumption, as well as requiring new and more carefully conducted feeding studies.

This maize cannot now be considered safe to eat. We are calling urgently for a moratorium on other approved GMOs while the efficacy of current health testing methods is reassessed.

The symptoms discovered in re-analyzing the data are consistent, and are evidenced in comparison to control rats of the same genetic origin, the same age, and caged in strictly similar conditions. They ate a diet of equilibrated chemical composition, assessed as equivalent to controls, but without the Bt toxin which is the insecticide produced by the GM maize itself.

On average, females show a weight gain, a significant increase of sugar and fat in the blood, an increase of liver weight relative to body weight, and disruption of renal function.

Inversely, the males lose weight, they are more sensitive at the renal level. The kidneys also lose weight in comparison to the body, and ions analyses are modified in urine. This may have a relationship with diagnosed nephropathies. . . .


Additional Information
For Dr. Arpad Pusztai‘s review comments commissioned by the German authorities on both the full 90-day study and a Monsanto summary, go to:

For Dr. Pusztai‘s review, in easy-to-read table form, of some of the significant differences found in the rat-feeding study, click here.

For Dr. Pusztai‘s list of reasons why the Mon 863 study should have been rejected, click here.

See detailed information on the study provided by Professor Seralini to the Greenpeace press conference at:

For the full 1139 page study, go to:

For Monsanto‘s 11 page summary of safety information, go to:

For the Friends of the Earth report on conflicts of interest in the European Food Standards Agency, go to:

Spilling the Beans is a monthly column available at Publishers and webmasters may offer this article or monthly series to your readers at no charge, by emailing Individuals may read the column each month by subscribing to a free e-newsletter at

1. Gilles-Eric Séralini, Dominique Cellier, and Joël Spiroux de Vendomois, "New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity," Archives of Environmental Contamination and Toxicology, 2007

© Copyright 2005 by Jeffrey M. Smith. Permission is granted to reproduce this in whole or in part.