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A Burning Controversy about
the Safety of Genetically Modified Food
by Joe Cummins, Emeritus Professor of Genetics,
University of Western Ontario
Genetically modified (genetically engineered) food is from crops that have been modified in the laboratory to contain genes that protect them from pests or affect their quality. Currently the technology demands that each construction should include a desirable gene, say to guard against pests, and an array of genes including virus genes and antibiotic resistance genes that are required for technical reasons. Crops currently on the market include soybean, corn, canola, cotton seed oil and potato.
In North America the genetically modified (GM) crops are mixed with crop that has not been altered and placed on the market without identifying labels. In Europe the public demanded identifying labels or restrictions on such crops. The crops have not been tested using animal studies and studies with human volunteers as is required for pesticides and pharmaceutical drugs. The decision not to label or to test extensively is based on a concept called "substantial equivalence," a belief that GM crops are equivalent in nutritional quality to crops that have not been genetically engineered. GM crops are present in most of the processed foods marketed in North America.
A mild-mannered Hungarian, Arpad Pusztai, immigrated to Scotland and rose to become a world authority in the important field of plant lectins at the Rowett Research Institute in Aberdeen, Scotland. Plant lectins are proteins that bind to sugar molecules that form part of the cell surface of mammalian cells and are involved in signaling for cell growth and metabolism. Lectins are also toxic to pests that browse on the plants. Dr. Pusztai shook the world of genetic engineering to its very foundation when he fed rats potatoes that had been modified with a lectin gene from the snow drop flower. Even though some lectins are highly toxic to humans, the developers of the GM potato believed that it would be toxic to insects, nematodes and fungi without harming mammals. To his surprise and alarm Dr. Pusztai found that rats fed the GM potato suffered damage to their immune system and digestive system.
The experiments commenced in 1995. During 1996 and on many occasions later Pusztai warned the Ministry of Agriculture of his growing concerns and in 1998 he warned government inspectors. In January 1998 he expressed concern in a BBC interview that the potatoes caused weakened immune systems. With full agreement from the head of the Rowett Institute Dr. Pusztai completed an interview with the World in Action Television, in which he said he would not eat GM potatoes. That interview was broadcast August 12, 1998.
Immediately after the interview Prof. James, the head of the Rowett Institute, released two press releases supporting Dr. Pusztai's work. However by August 12 Prof. James had changed his mind following pressure from the government and Monsanto Corporation. He suspended Dr. Pusztai and expressed regrets for releasing "misleading information." In October Prof. Ewen of Aberdeen University completed work from Dr Pusztai's team showing further organ damage in rats fed GM potatoes. An audit undertaken by Rowett cleared Pusztai of fraud but did not believe the data supported his conclusions. Dr. Pusztai was summarily retired and was not allowed access to his data.
The crops have not been tested using animal studies and studies with human volunteers as is required for pesticides and pharmaceutical drugs.
The British Royal Society entered the fray with its September 1998 review of the Rowett studies. The Royal Society President is Sir Aaron Klug, a native of Lithuania who was educated in Britain and South Africa and whose research has been with plant viruses. In his 1998 anniversary address to the Royal Society Sir Aaron stressed the need to merge academic science with industry, especially the chemical and pharmaceutical industries and he has maintained that goal. The review of the Pusztai experiments was undertaken by six anonymous peer reviewers. The Royal Society Report contained a truly bizarre and elementary error that reflects on their knowledge or motives. The Royal Society Report claimed the experimental animals were fed potatoes modified with "one particular gene." The focus of reports by Pusztai and Ewan was related to the impact of the lectin gene and its associated genes, particularly the virus promoter gene. That preliminary finding reflects on all GM crops on the market as all employ that virus gene. The Royal Society team may have simply failed to read the experimental reports because their minds were closed or there may be a darker motive. Nevertheless, the Royal Society concluded "testing GM food safety, when completed, should be peer reviewed and then published."
To his surprise and alarm Dr. Pusztai found that rats fed the GM potato suffered damage to their immune system and digestive system.
During February 1999 22 scientists from 13 countries signed a public statement in support of Dr. Pusztai. Two of those signing worked for the Rowett Institute, and all expressed concern over the attack on scientific freedom. Following extensive review and debate Dr. Pusztai was exonerated but not restored and he was not allowed to continue his important research.
On October 16 Ewen and Pusztai finally published a report on their studies in the medical journal Lancet. In that report they concluded that effects such as cell proliferation in the gastric lining were due to the lectin gene but that other parts of the genetic construction could have contributed effects, particularly on the small intestine and caecum. A related paper by researchers at the Scottish Crop Research Institute showed that snow drop lectin binds to human white blood cells, a cause for real concern about its ingestion by humans (Fenton et. al.,1999).
Normally, reviews of scientific papers are held strictly anonymous. This is understood by reviewer and those reviewed. However, Professor John Pickett of Rothamsted Research in Herfordshire came forward claiming he was a "senior reviewer," and outraged that his demand that the paper not be published was ignored, according to The Independent (London), October 11. Prof. Pickett did not ask Dr. Pusztai and Prof. Ewen if they agreed to a serious departure from the accepted understanding that such comments are not made public. Another scientist who would not allow his name to be used said it was wrong to publish the paper (The Independent, London, Oct. 11). Richard Horton, Lancet editor, appeared on BBC Newsnight and noted that three reviewers thought the work was worthwhile, one thought it flawed but publishable and the other two wanted it rejected. In the academic world there are many overbearing boors who enjoy destroying careers; sometimes in backwater institutions such boors hold sway and are allowed to dominate.
In his 1998 anniversary address to the Royal Society Sir Aaron stressed the need to merge academic science with industry, especially the chemical and pharmaceutical industries...
The Independent (London, Oct. 11) included one truly hilarious misleading quotation. Professor Martin Chrispeels of the University of California at San Diego said about the Lancet paper, "it would not be published in a serious plant biology journal." This comment is outstandingly silly because animal feeding studies are not published in plant biology journals because the editors have no qualifications in the area.
In conclusion, at last Dr. Arpad Pusztai and Prof. Stanley Ewen have published important findings on GM potatoes and their ability to injure rats (and presumably people). The advocates of genetic engineering have not taken this development well; at every step they have indicated that full and truthful scientific reporting is no longer sufficient. The bureaucratic establishment of science seems to require that reporting scientific results and even the results themselves should follow the stated desires of science bureaucrats.
References
Ewen, S. & Pustai, A. (1999). Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine. Lancet, 354 (9187), 1353.
Fenton, B., Stanley, K., Fenton, F., & Bolton-Smith, C. (1999). Differential binding of the insecticidal lectin GNA to human blood cells. Lancet, 354 (9187), 1354.
Royal Society. Review of data on possible toxicity of GM potatoes. May 18, 1999. http://www.royalsoc.ac.uk/st_p0l54.htm.
1988 Anniversary Address by President. http://www.royalsoc.ac.uk/annadd_2.htm
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