Organic Consumers Association


Previous Page

Click here to print this page

Make a Donation!


Genetically Modified Corn Study Reveals Health Damage andCover-Up

Spilling the Beans, June 2005


Genetically Modified Corn Study Reveals Health Damage and Cover-up

* Faulty Comparisons Hide Problems
* GM Food is Prone to Unpredicted Effects
* Flaws in the Mon 863 Study Should Have Caused It to be Rejected
* The Politics of Science Fails to Protect the Public
* US Pushes its Agenda, and its Pests, on Europe
* Additional Information <mip://031b4d88/default.html#Information>
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.

Genetically Modified Corn Study Reveals
Health Damage and Cover-up

By Jeffrey M. Smith, author of Seeds of Deception

When 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
who said that animals fed the genetically modified (GM) corn developed
extensive health effects in the blood, kidneys and liver and that humans
eating the corn might be at risk. The 1,139 page research paper on
Monsanto¹s ³Mon 863² variety also revealed that European regulators accepted
the company¹s assurances that their corn is safe, in spite of the
unscientific and contradictory rationale that was used to dismiss
significant problems. In addition, the study is so full of flaws and
omissions, critics say it wouldn¹t qualify for publication in most journals
and yet it is the primary document used to evaluate the health impacts.

Mon 863 is genetically engineered to produce a form of a pesticide called
bacillus thuringiensis or Bt, designed to attack a corn pest called the root
worm. Rats fed Mon 863 developed several reactions, including those
typically found with allergies (increased basophils), in response to
infections, toxins and various diseases including cancer (increased
lymphocytes and white blood cells), and in the presence of anemia (decreased
reticulocyte count) and blood pressure problems (decreased kidney weights).
There were also increased blood sugar levels, kidney inflammation, liver and
kidney lesions, and other changes. According to top research biologist Arpad
Pusztai, who was commissioned by the German government to evaluate the study
in 2004, based on the evidence no one can say that Mon 863 will cause cancer
or allergies or anything specific. The results are preliminary and must be
followed-up to rule these out. He warns, however, ³It 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, a molecular endocrinologist at the
University of Caen, agrees that the results indicate a toxic reaction.
Seralini is a member of two French government commissions that evaluate GM
food, one of which originally rejected a request for approval of the corn
variety in October, 2003 due to the adverse findings of the study. Seralini
won a French lawsuit allowing him to express his concerns in public, and now
Greenpeace has won a German court battle that makes public the data that is
the source of his concerns.

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 Union¹s
policy on GM food and crops. He has read all of the industry¹s GM-food
submissions to Europe as well as all the commentaries on the submissions.
Pusztai is the leading authority in his field of protein science (lectins)
and had been commissioned by the UK government in the 1990s to develop the
ideal testing protocol for all GM foods. Although his protocol was supposed
to be adopted by the UK government and eventually in Europe, Pusztai¹s
controversial finding that GM potatoes damaged the health of rats ultimately
stopped the work. Pusztai has also been commissioned to evaluate all
published studies on GM foods, and has analyzed most of the confidential
submissions made by industry.

Both scientists have 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 industry¹s defense, which Pusztai and Seralini say contradict
well established scientific principles. Chief among their concerns are the
ways Monsanto explains away statistically significant effects.

Faulty Comparisons Hide 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 will stand out. In this study therefore, the test
rats ate Mon 863 and the control group ate non-GM corn from the same parent
line, i.e., corn whose genetics are the same except for the insertion of the
genetic material and its impact. When comparing the results of these two
appropriate groups, the health impacts were unambiguous 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 the 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. While such comparisons are
appropriate for commercial studies, it is entirely inappropriate for a
safety assessment, according to Pusztai. Monsanto claimed that when the
changes in the test rats were compared to this much larger, irrelevant
control group, many changes were no longer significant.

2. In spite of the strained logic, many results were still statistically
significant when compared to these six other controls and were reported as
such by the laboratory that Monsanto used to conduct the study. Monsanto
therefore ignored the study¹s figures and claimed that since the changes in
the rats were still within a wide range of reactions that are normal for the
animals, they should be considered biologically irrelevant. Using this
argument, for example, they declared that a 52% decrease in reticulocytes
(immature blood cells) was ³attributable to normal biological variability.²
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% ³cannot be written off as biologically insignificant, given the epidemic
of diabetes.²

To put Monsanto's claims into perspective, suppose that a large number of
women who were fed a carefully controlled diet had a 25% increase in breast
cancer compared to matched controls on another diet. Using Monsanto's logic,
the findings can be dismissed because the increase was still within the
normal variability of breast cancer for the whole population.

3. In spite of the statistical slight-of-hand, several results could still
not be dismissed since they were well beyond the range Monsanto had defined
as normal. So the company claimed that the potentially dangerous health
effects were not considered significant 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, for
example, knows that there are differences between genders.

4. When even the gender defense could not be applied to a particular
finding, Monsanto dismissed it since the reactions were not always dose
specific. Specifically, the results observed in rats fed a diet that was 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.

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. In spite of EFSA's
recommendation to approve Mon 863, the majority of the countries in the EU
Council of Ministers voted not to approve the corn on July 24, 2005. But EU
law requires a "qualified majority" on such a vote, and so the pro-GM
European Commission is now authorized to make the decision and is expected
to 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. According to 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. Some included inflammation
disorders and problems in the livers and kidneys, the two major organs
involved with detoxification. Seralini is part of a research group raising
money to do independent research on a GM variety he says showed more than 50
significant rat anomalies.

GM Food is Prone to Unpredicted Effects

How can a GM crop create so many significant unpredicted side effects? There
are several ways. The process of gene insertion, for example, 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, for example, that the Bt pesticide may 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 that the composition of the Bt protein that
the corn creates is actually 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 pesticide in seven ways and should, according to Seralini,
require at least the same level of evaluation as chemical pesticides. The
same holds true for herbicide tolerant crops, which are engineered to
survive large applications of weed killers such as Monsanto's Roundup.
Seralini points out that these GM plants have far more herbicide residues in
the edible portions and extensive toxicity tests must be performed. But the
biotech industry claims that they could not afford to introduce GM crops if
they had to pay for the tests normally required for pesticides in Europe.
For GM crop approvals in the US, they spend even less. US authorities
require only 30-day studies for the Bt plants and no safety tests whatsoever
are required for herbicide tolerant varieties.

Flaws in the Mon 863 Study Should Have Caused It to be Rejected

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."

Several features of the study appear to have been rigged to avoid finding
problems. Nutritional studies, for example, 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 may have
hidden serious problems. Similarly, they used rats with a huge range of
starting weights. According to Pusztai, 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 case, says Pusztai, the wide range "can make it
impossible to find significant differences in animal weights at the end of
the experiment."

Monsanto tested the effects of two diets: in one Mon 863 constituted 33% of
the rats' diet, and in the other, it was 11%. Even in the 33% group, GM corn
protein comprised only about 15% of the rats' total protein. According to
Pusztai, 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 interesting to 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 and
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 will not give data about the intervening periods. And
the short 90-day time period will miss chronic and reproductive problems, as
well as problems in the next generation.

The analysis of the findings was obscured by using six irrelevant control
groups fed commercial diets, as well as data from historical databases. Such
comparisons are totally unacceptable in the field of nutrition. According to
Pusztai, "The study should have included a control group fed the non-GM
parent line, spiked with the Bt obtained from the Mon 863. If rats reacted
badly to this diet, it would show that the genetic engineering process and
its unpredicted side effects, and not the Bt toxin, were responsible.
Pusztai says, "A second parental line spiked with a known toxin would also
be useful as a positive control," to make 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. According to 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.
It failed to disclose, for example, the nutritional composition of the feed
- backed up by chemical analysis - and the methods used to measure changes
in the animals. Since these most basic requirements for a nutritional study
were not provided, the research cannot be repeated and the results remain

Referring to the study as a whole, Pusztai says, "Nutritional scientists and
leading journals would not accept these blatant inadequacies and

The Politics of Science Fails to Protect the Public

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 had
chosen 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.
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.

The 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." And 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 its Agenda, and its 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 that 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. 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 primarily in Italy, France, and Germany.

According to Seralini, "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. Since it takes about five years of
local field trials for a GM variety to be accepted in an EU nation, such
early testing was necessary.

In addition to the 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).

Critics demand that regulators use independent studies, not industry
studies, to prevent manipulation of data. 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 a rare, he ran into an unexpected obstacle. 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
the unintended effects, since most manufacturers refuse to use even approved
GM ingredients there (with the exception of animal feed). Meanwhile,
consumers in the US will unwittingly serve as the guinea pigs.

Additional Information
For Dr. Arpad Pusztai¹s 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, go to

For Dr. Pusztai's list of reasons why the Mon 863 study should have been
rejected, go to

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:

This GMO news service is underwritten by a generous grant from the Newman's
Own Foundation, edited by Thomas Wittman and is a production of the
Ecological Farming Association