When rats were fed Monsanto’s genetically modified (GM) maize Mon 863, they didn’t fare too well. In fact, Professor Gilles-Eric Seralini says they likely suffered a toxic reaction. It was difficult to pinpoint. Their increased basophils could mean allergies. Increased lymphocytes and white blood cells suggest infections, toxins or disease. The drop in immature red blood cells can occur with anaemia; and lower kidney weights may mean blood pressure problems. The rats also had increased blood sugar levels, kidney inflammation, liver and kidney lesions – they were a mess. What Seralini and other scientists wanted were further tests. What they got instead was approval of the maize on 8 August by the European Commission.
Mon 863 was not the first EU approved GM food to have shown significant health effects in rats. According to Seralini, a molecular endocrinologist and member of two French government commissions that evaluate GM food, an oilseed rape (GT 73), Roundup Ready maize (NK 603), and two Bt maize varieties (Bt11 and Mon 810) all showed statistically significant problems such as inflammation disorders and liver and kidney problems. Seralini said the effects of the GM crops were similar to pesticides.
But Mon 863 is unique. Not for the number of rat anomalies – others had more. Rather, its rat study is not secret. Biotech companies usually hide their research from the public claiming it is confidential business information. Seralini says, ‘No one can understand, even among EU regulators, why the composition of the blood of rats that have eaten the GM is secret.’ But on 20 June, 2005, a German court ruled in favour of Greenpeace, forcing Monsanto to release the Mon 863 study. With data in hand, we can understand why Seralini was so concerned. Moreover, we now know how much the pro-GM European Food Standards Agency (EFSA) and European Commission were willing to overlook in order to keep GMO approvals on track.
In the study commissioned by Monsanto, test rats ate Mon 863 maize, which produces Bt-toxin to kill the corn rootworm. The control group ate non-GM maize from the same ‘parent line’, ie corn whose genetics were the same before the Bt gene was inserted. Using the parent line is important. It minimises differences in the diet so that the impact of genetic modification stands out. And it did. According to the experimental design, the health effects in the GM-fed group were not due to chance. Nonetheless, Monsanto convinced EFSA to disregard the statistical significance and declare the maize safe. Here’s how.
1. Researchers used six additional control groups, each fed commercial maize varieties with varying genetics. Some changes in the test rats were no longer significant when compared to this much larger combined group. But according to Arpad Pusztai, an authority in animal nutrition studies and leading expert on GM research, comparisons with rats fed mixed genetic varieties are inappropriate and irrelevant for safety assessments.
2. Many health effects, nonetheless, remained significant even compared to these ‘artificial’ controls. So Monsanto claimed that they were biologically irrelevant if they fell within a wide range considered ‘normal’ for rats. To put this into perspective, suppose that a group of women who were fed a carefully controlled diet developed 50 per cent more breast cancer than women 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. Thus, Monsanto dismissed a 52 per cent decrease in immature blood cells as ‘attributable to normal biological variability’. According to Pusztai, an allowance of five per cent variability is the norm in food experiments. Similarly, he says that the increase in blood sugar levels by 10 per cent ‘cannot be written off as biologically insignificant, given the epidemic of diabetes’.
3. In spite of the statistical slight-of-hand, several results were still outside Monsanto’s ‘normal’ range. They offered another excuse. Since the reaction among the rats was not consistent between males and females, it was not significant. ‘This is really ridiculous,’ says Seralini, who points out that everyone studying cancer and endocrinology knows that there are reaction differences between genders.
4. And when the gender defence did not apply, Monsanto dismissed results claiming the reactions were not dose specific. Specifically, changes in rats whose diet was 11 per cent Mon 863 were sometimes more pronounced than those fed a 33 per cent diet. Here again, Seralini says Monsanto’s claims conflict with scientific understanding. In endocrinology and toxicology research, differences are not always proportional to their effects. 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. Pusztai, commissioned by the German government to evaluate the study in 2004, wrote, ‘It is almost impossible to imagine that major lesions in important organs (kidneys, liver, etc) or changes in blood parameters (lymphocytes, granulocytes, glucose, etc) that occurred in GM Maize-fed rats, is incidental and due to simple biological variability.’
Rigged and shoddy research
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. Monsanto used a mix of young and old animals, which may have hidden serious problems. Similarly, they used rats with a huge range of starting weights. Male rats ranged from 198.4 to 259.8 grams (or 143 to 186 grams according to conflicting data in the study’s appendix). According to Pusztai, starting weights should not vary more than two per cent from average. The wide range ‘can make it impossible to find significant differences… at the end of the experiment.’
African aid recipients rely on maize for about 90 per cent of their calorie intake. Rats are stand-ins for humans. 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 dose effects. The maximum amount of GM maize fed to the rats was 33 per cent of their diet, constituting only about 15 per cent of their protein.
According to Seralini, Mon 863 is new and unique; it differs from natural Bt toxin in seven ways. It should require at least the level of evaluation used for chemical pesticides. In the EU, that requires research on three types of mammals, with studies ranging from 90 days to two years. Mon 863, however, was approved after only a short 90-day rat study. Chronic and reproductive problems, and impacts on the next generation would all be missed. And the study had just two observation times (week five and week 14) using analytical methods that are half a century old. They ignored powerful new methods, such as profiling techniques, DNA chips, proteomics, and others.
Some of the reported weight measurements were also bizarre. 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, poorly reported and at a whopping 1,139 pages, seemed to try and hide results in a mountain of irrelevant material. It failed to disclose the methods used to measure changes and therefore the research cannot be repeated and the results remain suspect.
Referring to the study as a whole, Pusztai says: ‘Nutritional scientists and leading journals would not accept these blatant inadequacies and misinterpretations.’ He adds, ‘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.’
The German court’s decision to make the Mon 863 study public may open the door for more such revelations. 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. This appears to be the case with his French Commission for Biomolecular Genetics (CBG), which originally refused to approve Mon 863 based on the evidence. The CBG’s president, a geneticist who works very closely with industry, asked a consultant to re-evaluate just one significant difference and then forced a second vote without a quorum. With only five of 18 members present, Mon 863 passed three to two. According to Seralini, one of the scientists who voted in favour 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 EFSA, which has come under attack for including primarily pro-GM scientists. ‘One member has direct financial links with the biotech industry and others have indirect links,’ according to a November 2004 report by Friends of the Earth. 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’. And ‘two members have even appeared in promotional videos produced by the biotech industry.’
It is no surprise, therefore, that EFSA endorsed and even repeated each of Monsanto’s excuses why the statistically significant health effects of rats fed Mon 863 were not relevant. The majority of EU Council of Ministers, however, ignored EFSA’s recommendation and on 24 July voted not to approve the Mon 863. But since EU law requires a ‘qualified majority’, it was passed onto the Commission who gave its approval for consumption by European citizens.
Perhaps EFSA and the European Commission will be more careful to require truly scientific arguments and rigorous research, now that industry studies may be made public. In the meantime, we still don’t know how sick the rats were that ate Mon 863. And we have no idea of the impact on humans.
This article first appeared in the Ecologist October 2005
