Commentary -- Russian GM potato study
This paper is published here by GM Free Cymru with the intention of increasing public awareness of important research work which has been kept out of the public domain. The Report in question has been suppressed for about 7 years, and has only recently come to light thanks to the efforts of Greenpeace Russia.
COMMENTARY ON THE REPORT ABOUT THE FEEDING OF RATS BY MONSANTO'S GM RUSSET BURBANK Bt POTATOES
I.V.Ermakova, Agrarian Russia, No 4, 2005, pp.62-64.
The Commentary is based upon an analysis of the following document:
((Medical-biological investigations of transgenic potatoes, resistant to the Colorado beetle (under agreement with Monsanto Co.) Russian Academy of Medical Sciences, Institute of Nutrition, Moscow, 1998. Signed off by V.A.Tutelian, Deputy Director. Physiological, biochemical and morphological investigations in rats. Full Report 275 pp, including raw data.))
This translation has been prepared by Ian Panton and Brian John of GM Free Cymru, in consultation with the author.
The analysis of the relevant part of the Institute of Nutrition Report showed that the studies were not carried out according to the accepted protocols for the biomedical assessment of GM food and feed (1). Many of the conclusions drawn by the authors do not correspond to the obtained data and therefore they are incorrect.
Two types of Russet Burbank potatoes - the GM potatoes (GM-RB) and potatoes bred by traditional methods (RB) were sent to the Institute of Nutrition by Monsanto for feeding studies. Experiments were conducted only on small groups of animals: 10 rats in each group, which is absolutely inadequate for such vital studies. In the course of the experiments some rats perished, and the data were given only for the surviving groups of 8 and sometimes even of 6 animals. Serious morphological changes in internal organs were observed in rats when they were fed Russet Burbank potatoes (both the GM-RB and RB varieties), which were added to the ration of animals in boiled form. Changes in the liver, kidneys, and large gut; reduction in hemoglobin; strengthening diuresis; and changes in the mass of heart and prostate gland and others were observed. In the course of the first month of feeding, animals showed reduced body mass in comparison with the control group. The strongest changes in the organs were discovered in rats fed by the GM-RB potatoes. Both types of Russet Burbank potatoes (RB and GM-RB) were dangerous for animals. The genetically-modified potatoes GM-RB were especially toxic. However, the Institute of Nutrition concluded that "the studied types of potatoes can be used in human nourishment for the conduct of further epidemiological studies", i.e. during the study of the clinical picture of diseases and their distribution among the human population.
Data on pathological changes in the organs and biochemical parameters in the rats fed on Russet Burbank potatoes (RB and GM-RB), in comparison with the rats without potatoes in the control group, are given in the next section.
I. Scheme of experiments
The transgenic potato GM-RB was obtained by the introduction into genomic DNA of the Cry3A gene, isolated from Bacillus thuringiensis subsp-tenebrionis (B.t.t.) and of the gene of neomycin- transferase II (NPTII), isolated from prokaryote transposon Tn-5. Genes Cry3A and NPTII were introduced into the potatoes with the use of the binary plasmid vector Agrobacterium tumefaciens. Both genes expressed themselves in the potatoes in the form of insecticidal activity against the Colorado beetle. The expression of genes occurs in the entire plant, but especially in the leaves.
The feeding experiments were conducted with three groups of Wister rats with an initial weight of 80-100g: one GM experimental and two non-GM control groups. The rats of the first control group ("control") obtained standard chow during the full course of the experiment. To the rats of the second control group (group RB) normal Russet Burbank potatoes in boiled form (12g per day) were added to the chow. To the rats of the experimental group (group GM-RB) the genetically-modified (or transgenic) potatoes (12g per day) in the boiled form were added to the chow. The duration of the experiments was 6 months. Some animals were killed after 1 month and the others 6 months after the beginning of the experiments.
II Chemical composition of potatoes
It is necessary to focus attention on the chemical composition of Russet Burbank potatoes. In 1998-2000 in the UK it was revealed that GM potatoes strongly differ in their chemical composition from traditionally-bred potatoes and cause damage to the immune system. Both of the American Russet Burbank potatoes differ in chemical composition from the potatoes bred and used in Russia. Differences were discovered in many parameters. Russet Burbank varieties have, in comparison with Russian potatoes, very much lower concentrations of some vitamins measured as mg/100g: for example, B2 - 0,013 (in Russian potatoes - 0,07); B6 - 0,162 (in Russian - 0,3), vitamin E - 0,017 (in Russian - 0,1). As to mineral composition (measured as mg/kg) the Russet Burbank potatoes showed reduced concentrations of iron - 6,4 mg/kg (in Russian - 9,0 mg/kg); sodium -33,4 (in Russian - 50), potassium - 4052 (in Russian - 5680) and especially calcium - 10,4 (in Russian - 100) and many others.
Researchers from the Institute of Nutrition, describing the RussetBurbank potatoes, concluded that "in all studied parameters the transgenic potatoes do not differ from the potatoes of the same type, bred by traditional methods.........". However, the Russet Burbank GM-RB potatoes had two times less fructose glucoses than the traditional potatoes; three times less Beta-carotene; and there was no vitamin E. Thus, the content of some fatty acids in the GM potatoes was increased 1,5-3 times and nitrates by 2 times.
III Toxicology-hygienic studies on the laboratory rats
Two series of the experiments were carried out at 1 month and 6 months.
One month studies
Pathological changes in the rats that ate potatoes were already manifested with the analysis of the body mass of rats in spite of an adequate diet of potatoes, which in the GM-RB group of rats was increased in comparison with the RB group to 1-2.5g, the body mass of rats in the RB group and, especially, in the GM-RB group was statistically significant lower than in the "control" group. If prior to the beginning of experiment the body mass of the rats of all groups was practically identical (Control: 73.5 + 1.9g; RB: 72.5 + 2.8g; GM-RB group: 72.7 + 1.6g), then after one month of feeding the RB rats and GM-RB rats showed body mass significantly lower than in the "control" group. If in the "control" group the body mass was totalled to 231.4 + 9.0g, in the RB group it was 36,4g less (195.0 + 11.0g), and in the GM-RB group it was almost 50g less (181.6 + 8.3g).
In the RB and GM-RB groups, in comparison with the "control" group, it was revealed that there were pathological decreases in the absolute mass of almost all the studied organs (data from 8 rats): kidneys, liver, spleen, heart, testes, hypophysis, and prostate gland. In this case the most explicit decrease in absolute mass was observed in the GM-RB group, and especially in the absolute mass of the heart and prostate gland.
Obtained data were less clearly expressed with the analysis of relative values. According to the hematological parameters of the peripheral blood in the GM-RB rats (data from 6 animals) it was observed that there was a statistically significant reduction in hemoglobin concentration in comparison with the "control" group but an insignificant decrease (possibly because of the small number of animals) in comparison with the rats of the RB group.
Six month studies
With the more prolonged feeding of rats by Russet Burbank potatoes the absolute body mass of the animals was statistically lowered in the RB and GM-RB groups in comparison with the "control" group. The difference was 40-50g after first 8 weeks of feeding ("control": 264.8 + 8.8g; RB group: 224.9 +12.5g. and GM-RB group: 220.7 + 9.1g).
After 12 weeks the body mass figures were as follows: 12 weeks ("control": 309 + 7.6g; RB group: 258.7 + 9.5g; and GM-RB group: 267.9 + 15.9g).
Pathologic changes were revealed with the analysis of the absolute and relative mass ratio of internal organs. The absolute and relative mass ratio of the liver was statistically significantly reduced in the RB and GM-RB groups in comparison with the "control" group. The absolute mass of kidneys was statistically significantly lower in the RB group in comparison with the GM-RB and the "control" groups. The absolute mass of prostate gland was increased in GM-RB group (statistically significant) and the RB group (insignificant) in comparison with the "control" group. The mass ratio of testes was reliably increased in the RB group in comparison with other groups.
The content of total protein in the blood serum of rats was statistically significantly reduced in the GM-RB group in comparison with the RB and "control" groups. Daily diuresis (ml) and relative density in the GM-RB and RB groups were statistically increased, and the content of creatinine was statistically reduced in comparison with the control. Hemoglobin concentration in the GM-RB and RB groups were statistically reduced in comparison with the "control" group. Statistically significant changes were also observed in the leukocyte formula (on the neutrophils and the lymphocytes) in the RB rats in comparison with the "control" rats.
IV Morphological studies at 1 month and 6 months
During the experiments 4 rats died: two rats from the GM-RB group (showing abrupt changes in the large gut and in the liver), and two rats from the "control" group (due to pneumonia). Serious changes in the liver, kidneys and large gut were observed in the rats from the GM-RB group after their killing, in contrast to other groups. The liver in the rats from the GM-RB group had lighter yellow-brown colour, and was easily torn. Cysts in the kidney and in the liver were discovered in 3 rats out of 8 during the six month study (i.e. ~ 40% of rats). Signs of adipose dystrophy appeared in the cells of the liver (the hepatocytes) in rats from the RB-GM group, which were rarely noted in the RB group. Different sizes of cellular infiltrations were discovered in the large gut in rats from the GM-RB group. Changes in the large gut were not discovered in either the "control" or RB groups.
A number of Russian and foreign researchers have drawn conclusions about the imperfections of the biotechnological methods used for gene introduction into plants, and have drawn attention to the serious dangers presented by GM organisms and their containing products to man, animals and the environment. Plasmids and foreign GM-inserts can fall into the cells of different organs as a result of horizontal displacement, leading to pathologic changes in those who eat GM food.
Both types of Russet Burbank potatoes (fed to the RB and GM-RB groups of rats) lead to changes in the blood and internal organs of laboratory rats (in the liver, the kidneys, the large gut, a change of the dimensions of heart and prostate gland and others) and on the basis of this evidence they CANNOT be used in the nourishment of people.
The genetically modified potatoes were most dangerous. Arpad Pusztai and Stanley Ewen demonstrated pathological changes in different organs (liver, spleen, kidneys, stomach, rectum and others) in rats which were fed on GM potatoes and GM corn (Pusztai, 1998, 2001; Ewen and Pusztai, 1999; see also the journal "Agrarian Russia" No1, 2005).
Further studies are necessary on a large number of animals (in each group there must be not less than 20 rats) in order to fully explain the reasons for the negative influence of the Russet Burbank potatoes (both GM and non-GM) and other GM cultures on the organism of animals. In this case it is necessary to compare the apparently damaging influence of GM-potatoes on animals as against traditional Russian varieties. It is possible that a sharp increase recently in Russia in the number of oncological diseases, especially of intestinal tract and prostate gland, and of leukemia (according to data from the Medical Information Agency), is connected with the increasing use of GM-components, including GM-potatoes, in human food products.
I.V. Ermakova, Doctor of Biology, Institute of Higher Nervous Activity and Neurophysiology RAN [RUSSIAN ACADEMY OF SCIENCE]
(1) MIN 2000 - Methodical Instructions for the checking of GMOs in food
Go to a Print friendly Page
Email this Article to a Friend
Back to the Archive