Considerable increase of foodborne diseases in the US - GE foods are a likely cause

Why this great increase of virus-caused diseases in the US?

Mae-Wan Ho, director of the Institue of Science in the Society, and an expert on food biotechnology notes in a recent report that there is a very pronounced difference between Sweden and the US in one respect - the rate of virus-caused illnesses. While in Sweden, viruses were the cause in only 9% of the cases, they were so in 80% of the cases in the USA.

The reason for this increase is unknown. But Mae-Wan Ho points out that the use of genetically engineered foods has increased enormously in the US since 1994. By comparison, in Sweden, almost no GE foods were used in 1999.

GE crops can generate new viruses

Ho suspects that a possible reason might be that GE foods may give rise to new viruses. This has been well established scientifically (even the biotech firm Monsanto has acknowledged this). The reason is that every cell in a GE plants contains parts of virus genes that can combine with the genes of infecting viruses. In a very large proportion of GE crop varietes, the virus genes come from a virus (Cauliflower Mosaic Virus - CaMV) related to human viruses. Therefore some scientists have warned that GE plants may give rise to new human viruses. For more, see "The Cauliflower Mosaic Virus promoter - a hazard in GE plants".

New bacterial pathogens?

Ho has warned that so called vector DNA used in all GE crops may also be a culprit. This DNA comes from virus and bacteria and facilitates the combination of genes of unrelated species. Thereby it might promote the emergence of new bacteria. For more, see "Horizontal transfer of viral and bacteria DNA facilitated by GE organisms?"

Source: "US Foodborne Illnesses Up Two to Ten Fold" ISIS Report, 3 November 2001

Comment

We agree that the large scale cultivation of GE crops brings with it a definite risk for the emergence of new viruses. But if this were the cause of a major part of foodborne disease increase, it should also have caused a considerable increase of virus diseases affecting other organs. We are not aware that this has happened. So we assume that, if new viruses have contibuted to the increase of foodborne diseaes, it is likely to be to a minor extent.

We propose another explanation how GE foods might be the cause. It is based on the remarkable fact that 82 % of the foodborne diseases and 25% of the death cases were caused by "unknown pathogens", assumed to be viruses, in the american study that Ho refers to, (Mead PS, Slutsker L, Dietz V et al. Food-related illness and death in the United States, Emerg Infect Dis 5:607-25; 1999).

This could be explained by the fact that, in practical medicine, the diagnosis of severe diarrhea occurs through exclusion. That is, if no common pathogens causing severe diarrhea, like salmonella, shigella etc. are found, and systemtic diseases (Mb Crohn, ulcerating colitis) are ruled out, it is commonly assumed that the disease is caused by a virus. But as it is costly, not useful and in practice impossible to detect all possible viral pathogens, little or no viral testing is done (as there is no specific therapy for viral diseases, specific diagnosis is of no help).

We suggest that the increase may have been caused by GE foods in two possible ways:

1. By the Bt-toxin, found in most commonly eaten genetically engineered food.
2. By bacterial DNA used for genetic engineering in almost all GE foods.

Explanation

1. Major GE crops have been genetically engineered to produce the Bt toxin for its insecticidal ability.

Professor Joe Cummins has pointed out that an Egyptian study indicates that the Bt toxin causes intestinal irritation which may case acute as well as chronic gastrointestinal illnes ("Fine Structural Changes in the Ileum of Mice Fed on -Endotoxin-Treated Potatoes and Transgenic Potatoes" Natural Toxins Volume 6, Issue 6, 1998. Pages: 219-233 Published Online: 29 Jun 1999 Nagui H. Fares, Adel K. El-Sayed). This study found that mice, fed with genetically engineered potatoes, developed significant intestinal changes indicating an irritative effect of the toxin. For more, see Cummins, J.: "Comments on the human health impact of Bacillus thuringiensis toxin gene product in genetically modified crops".

In addition, a number of field reports indicate severe and in many cases lethal, gastrointestinal damage in cows and sheep eating GE plants containing Bt-toxin, see for example Cows ate GM Maize and died and Mass Deaths in Sheep Grazing on Bt Cotton.

As the Bt-toxin demonstratedly affects animal intestines, it cannot be excluded that it might cause disturbances in humans as well, manifesting as "foodborne disease with unknown origin". Biotech proponents assert that this toxin is degraded by stomach acid. However this is contradicted by the studies and experiences reporting severe gastrointestinal damage from eating GE-food containng Bt-toxin. This toxin is actually quite acid resistant and, moreover, people may have a low level of gastric acid because of disease or because of the very common use of Losec or similar potent antacid preparations. So even if it were degraded by a normal level of gastric acid, a considerable proportion of the population would be at risk.

As the foods are not labelled as GE, the connection is not apparent to the consumer. According to Cummins, no studies have been done that reliably exclude that Bt-toxin in the food can cause gastrointestinal damage.

2. Professor Joe Cummins has pointed out that certain bacterial DNA sequences present in practically all GE crops may incearase the risk for inflammatory disorders. These socalled CpG sequences are found in the DNA used for enabling gene insertion (vectors) and in many of the primary crop protection genes including Bt and most herbicide tolerance genes. This bacterial DNA contains considerable amounts of the CpG sequence (higher forms of life, so called eukaryocytes, have little of this sequence and it is in a different state). It has been established that this sequence induces inflammation (it has been found to adversely affect autoimmune inflammatory diseases ).

Inflammation induced in the bowel by this bacterial DNA in GE foods is likely to mimic foodborne diarrhea. As no bacterial pathogen is found, and if the diarrhea is persistent, the routine is, as explained above, to assume that it is caused by one of the many viruses that cause diarrhea.

For more, see "The fate of food genes and the DNA CpG motif and its impact".

Conclusion

There are two conceivable ways in which GE foods may cause gastrointestinal disturbances in addition to those proposed by Ho. It is through the action of the Bt toxin in common GE foods, including maize and soy, and through the action of the CpG DNA sequence that induces inflammation.

So there are a number of likely explanations of the large increase of foodborne diseases in the US while in Sweden, where no GE foods were available during the same time period, there was no increase of the same disorders, although the food habits are similar.