Monsanto GM soybean safety assessment flawed, Japan researcher says
(Sunday, Nov. 16, 2003 -- CropChoice news) -- Pacific Ecologist: Monsanto's safety assessment application to the Japanese health ministry for Roundup Ready soybeans was "inadequate and incomplete," according to assistant professor MASAHARU KAWATA , of Nagoya University, Japan.
Monsanto maintains there is no difference between GM soybeans and conventional strains. But according to the Japanese study, Monsanto's safety tests misrepresent data and included testing proteins not derived from the GM plant; insufficient feeding experiments; and intentional neglect of "inappropriate" data. Since the components of the GE soybean that people are eating are still unknown, governments who have approved the GE soybean should review their safety assessments.
Tested soybeans not exposed to herbicide
Commercial crops of Roundup Ready soybeans are usually sprayed with the herbicide Roundup (glyphosate). However, both the genetically modified soybean strain and the parent strain that Monsanto used for feed tests were NOT sprayed with Roundup herbicide during cultivation. Monsanto produced a minimal amount of soybeans grown with applications of Roundup, but only enough to test for glyphosate residues. This testing checked for residual gl yphosate, a toxin that kills plants by inhibiting a plant enzyme , in the harvested forage, hay and seed. But testing was not done on the effects on other metabolic pathways which must also be taken into account when such artificial genes are inserted.
Several tons of soybeans used in the safety assessments were not produced with Roundup. No explanation is given for this in the documents. For consumers, the test results obtained by using a sample grown differently from the GE- marketed soybean are meaningless.
GE soybean amino acid sequence unknown
The protein Monsanto analysed was from E.coli, not from RoundUp ready soybeans! Testing assumed the protein expressed in the bio-engineered soybean has the same amino acid sequence as the soil bacterium E coliform from which the genetically engineered gene was extracted. This can only be verified when the soybean-produced protein is isolated and the amino acid sequence is determined. Exchanging genes between bacteria and a higher organism can sometimes result in partial change of amino acid and/or post-translational modification after expression. It was presumed Monsanto had determined the amino acid sequence of the GE soybean but it had not.
Monsanto sequenced only 15 amino acids from the protein that was expressed in E. coliform. The rest of the sequence was an assumption about the sequence of the bacterial DNA. They determined only 3.3% of the expected total of 455 amino acids and the protein is not from soybeans. The test described in the documents is the only method to verify antigenic equivalence of proteins. But antigenic similarity itself does not prove that the amino acid sequences are the same. The real sequence of the GE protein in the soybean that we are eating is still unknown.
Animal tests used wrong protein
Acute toxicity tests on rats were also carried out using the protein produced by E. coliform. Monsanto says in the application that extracting large amounts of the GE protein from soybean is difficult. This is an unaccept able excuse because there is a possibility that the inserted gene works differently in soybean than in the original bacterium. Moreover, according to the application document, 0.238mg of GE protein is detected in one gram of genetically modified soybean, which is enough to extract without difficulty.
This kind of problem could be resolved if all the amino acid sequence in GM soybeans had been sequenced and confirmed equal as the bacterium. The experiment appears to have been conducted on the presumption that the other GE soybean proteins are the same as the non-GM soybean as long as they are not toxic. If so, this is too easy an assumption and a one-sided approach. The core of this problem is whether or not the soybean gene is affected by insertion of a foreign gene. The series of experiments described are fundamentally invalid.
Minimal feeding tests
Animal feeding tests are important for safety assessment. Monsanto conducted these experiments on rats, cows, chickens, catfish and quail. However, the scale of the experiments was very inadequate. For example, in rat experiments, raw and toasted soybeans both genetically modified and non-modified were fed to only 10 rats in each group and the feeding period was only 28 days. Toxicity across generations or chronic toxicity will not be measured by such limited experiments.
Even with these far from satisfactory experiments, the data for body and organ weight of liver, kidney and testicles show obvious differences in the male rats between groups fed wild strain soybean and those fed bio-engin eered soybean.
Raw soybean-fed groups showed no difference. But male groups fed toasted GE soybean, weighed 6.7% less than the group fed the ordinary soybean and 13% less than the group fed the commercial feed-mix at the end of the tes t period of 28 days. Though this difference is described as statistically significant in the data sheet, the conclusion ignores these results and states that "no statistical significance is observed."
The experiments were far from satisfactory both in the samples and the statistical method used. The Nagoya University group transcribed all raw data and redid the statistical analysis. The result again showed the apparent growth obstacle for the body and kidney weight in the male rats group fed toasted GE soybean. There was no such difference in the female rats group, possibly due to the amount of the feed intake. Where males took 25-30g /day, female rats took only 18-20g (approx. 70% of male)/day. It is highly possible that female rats would also show significant growth difference if the experiment was conducted on a much larger scale, with a longer feed ing period.
Misinterpretation, false conclusions, ignored data
The Japanese researchers found clearly intentional misinterpretation in the Monsanto assessment. This was caused through ignoring the differences shown in the documents between the ordinary soybean and the GE hybrid. Obvious differences appeared after toasting at actual feed processing condition (108 degrees celsius, 30min). While the concentration of total protein and potassium was not changed, the concentration of trypsin-inhibitor, ure ase, and lectin were significantly higher in the toasted GM soybean, compared to that of the normal soybean. These physiologically active substances remained active even after heat treatment in the genetically modified soybean. However, those in the herbicide-sensitive normal bean were easily denatured and inactivated.
Monsanto took this result to mean "the modified soybeans are not toasted sufficiently in the experiment" and returned and asked for re-treatment of the sample to Texas A & M laboratory who processed the beans. Monsanto ordered the temperature of re-toast at 220 degrees Celsius for 25min, which is considerably higher than normal processing of 100 degrees Celsius, 10 minutes. However re-toasting further widened the difference in the activity between the two strains. Another genetically modified soybean inserted with a bacterial gene, also showed high heat-resistant properties.
Scientists would usually conclude by these results that there is substantial difference between the two. But Monsanto dared to challenge this common practice and concluded the second toasting was still not enough. In the end, they toasted two more times and got the result they wanted, i.e. all proteins were denatured and inactivated. With this result, they concluded that genetically modified and non-modified soybeans have equivalent prope rties.
No protein can withstand repeated heat treatment and stay active. This is common knowledge of protein chemistry. Monsanto based their argument on their presumption that "they can't be different" and their need that "they shouldn't be different." Their translation of the experiment is based on "the conclusion is safe" attitude but it is not at all scientific.
Monsanto asks governments to lower safety standards
Adopting the Roundup tolerant soybean would increase the herbicide concentration in the soybean plants and seeds, because the herbicide is directly sprayed on the plant before harvest. Monsanto studied in detail the resu lts of changing factors like spraying times, concentration of the active ingredient glyphosate, duration of harvest after spraying and growing locations.
The data shows clearly that the concentration of glyphosate and AMPA (a degraded substance of glyphosate) in forage and hay was increased greatly by post-emergence application of the herbicide compared to that of conventi onal pre-emergence application, although the residual concentration in the plant differed from place to place. The largest value of the combined glyphosate and AMPA was 40.187 ppm in forage which is higher than the US saf ety standard of 15 ppm in forage and hay in 1994 when FDA and USDA accepted the application documents.
In the final conclusion, Monsanto says: "the maximum combined glyphosate and AMPA residue level of approximately 40 ppm in soybean forage resulting from these new uses, exceeds the currently established tolerance of 15 ppm. Therefore, an increase in the combined glyphosate and AMPA tolerance for residues in soybean forage will be requested."
The US tolerance standard of combined glyphosate and AMPA in soybean forage was increased to 100 ppm after they approved the GM soybean. The Japanese government also revised the safety standard of combined glyphosate and AMPA in soybean seed from 6ppm to 20ppm in April 2000 at the request of the US government. By legalising the increase, Japan could import soybeans from the US without violating the law.
Monsanto patch-worked the results of experiments with analyses that are full of holes, and manipulated the results. They even requested the revision and lowering of safety standards. The Nagoya University team discovered facts showing inadequate and incomplete safety assessment in the application document by Monsanto. The process of genetic recombination and the results of other animal experiments remained uninspected by the team.
In May 2000, Monsanto informed countries importing US soybeans that Roundup resistant soybeans had two extra gene fragments in the genome. They were there when the US FDA gave the initial approval to the GE soybeans in 1992. All the GE soybeans supplied worldwide contain these gene fragments. Monsanto asserts that these fragmented genes do not create unknown proteins.
But for such basic facts to come to light eight years after the approval is a clear indication of how incomplete is the state of knowledge about the genetic recombination of crops. It also demonstrates how dangerous it is for governments to rely on a commercial company's information for data and safety assessments. We question the wisdom of experts at the Japanese Ministry of Health and Welfare who concluded that the genetically engine ered Roundup Ready soybean was safe, based on such an inadequate and incomplete application.
Postscript: In a note to the editor early August 2003, Professor Kawata said the research on the Monsanto soybean application was sent to Japan's Agriculture and Fisheries Ministry two years ago. However there has been no response from the authority about the flaws discovered in the application, and Professor Kawata still awaits a response from Monsanto-Japan.
- Masaharu Kawata, Assistant Professor, School of Science, Nagoya University, Japan This article was written in May 2001 and has been slightly adapted for publication in Pacific Ecologist.