Genetically Modified Potatoes Damage Rat Intestine, The Pusztai Affair and The Stranglehold Biotech Firms Have On Research

Dr Árpád Pusztai

A series of studies on rats fed genetically modified potatoes, conducted by biochemist Arpad Pusztai, were summarized in this article which appeared in the Lancet in 1999:

Effect Of Diets Containing Genetically Modified Potatoes Expressing Galanthus Nivalis Lectin On Rat Small Intestine, Lancet, 1999

Pusztai's researchers describe their work:

"We compared the histological indices of the gut of rats fed potato diets containing GM potatoes, non-GM potatoes, or non-GM potatoes supplemented with GNA*, to find out whether GNA gene insertion had affected the nutritional and physiological impact of potatoes on the mammalian gut."

* GNA is short for Galanthus nivalis agglutinin. It is a lectin produced by the snowdrop plant; it acts as an insecticide. Potatoes were genetically modified to incorporate the GNA gene so that they produce this insecticide. On a related note, most of the corn and cotton grown in the US today has been genetically engineered to contain a gene from the bacterium Bacillus thuringiensis (Bt). Like the GNA gene, the Bt gene produces an insecticide in every cell of the genetically engineered corn and cotton plants.

Pusztai, "a world expert on plant lectins, authoring 270 papers and three books on the subject" and his team found:

"Diets containing genetically modified (GM) potatoes expressing the lectin Galanthus nivalis agglutinin (GNA) had variable effects on different parts of the rat gastrointestinal tract. Some effects, such as the proliferation of the gastric mucosa, were mainly due to the expression of the GNA transgene. However, other parts of the construct or the genetic transformation (or both) could also have contributed to the overall biological effects of the GNA-GM potatoes, particularly on the small intestine and caecum."

Note that last sentence. Damage to the rats' intestines could have been due to the protein produced by the inserted gene (the lectin), or due to changes in the potato resulting from the genetic modification process. These collateral changes have not received much attention in research.

Pusztai announced that the results of his research showed feeding genetically modified potatoes to rats had negative effects on their stomach lining and immune system. He said, "If I had the choice I would certainly not eat it."

There was a media frenzy following his public statements. Pusztai was suspended from the Rowett Research Institute in Scotland where he worked for 36 years, his annual contract was not renewed, his data was seized, and he was banned from speaking publically. All of this is described in the Pusztai Affair.

This was troubling:

"Investigative journalist Andrew Rowell wrote in his 2003 book Don't worry, it's safe to eat: The true story of GM food, BSE and foot and mouth that pressure to sack Pusztai had been applied to the institute from Monsanto, a multinational company that owns 90 percent of GM seed technology.
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According to Rowell, "US President Clinton* rang Prime Minister Blair who then rang [Rowett Institute Director Philip] James to tell him to silence Pusztai."

* Monsanto is a key member of the Clinton Global Initiative, a project began by Clinton in 2005 to "convene global leaders to devise and implement innovative solutions to the world’s most pressing problems" such as hunger.

Pusztai's coauthor on the study at the top of this post, Dr. Stanley Ewen, said he also found his career options "blocked at a very high level" after publication of the findings. He subsequently retired.

Pusztai's work was later supported by several European and American scientists:

"Twenty-one European and American scientists released a memorandum in support of Arpad Pusztai, a protein biochemist who was suspended last year by the Rowett Research Institute in Aberdeen, Scotland, after he sounded an alarm in a TV interview about potatoes altered to resist pests. The scientists said Pusztai's statements were correct and demanded that the Rowett Institute exonerate him."

Regarding potatoes today, Wikipedia says there are currently no GMO potatoes marketed for human consumption. A potato brought to market by Monsanto in the 1990s was withdrawn in 2001. However, in 2011 BASF requested approval in Europe for its new GMO Fortuna potato.

If genetically engineered foods are indeed safe to consume, why isn't evidence of this safety pursued in independent research and itself used to discredit anti-GMO activists? One reason is that big agribusiness firms like Monsanto and BASF and Syngenta have prohibited this research. Here's a statement* from 26 university crop scientists sent to the EPA in 2009 describing their inability to conduct research on GMOs:

"Technology/stewardship agreements required for the purchase of genetically modified seed explicitly prohibit research. These agreements inhibit public scientists from pursuing their mandated role on behalf of the public good unless the research is approved by industry. As a result of restricted access, no truly independent research can be legally conducted on many critical questions regarding the technology, its performance, its management implications, IRM, and its interactions with insect biology. Consequently, data flowing to an EPA Scientific Advisory Panel from the public sector is unduly limited."

* Picked up by the New York Times here, and by Scientific American here.
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