We recently forwarded comments from Prof Joe Cummins on a Natral Toxins paper indicating damage to the ileum, an important part of the small intestine, from a GM crop involving the Bt toxin (Abstract and Prof Cummins' comments reproduced below together with information about the function of the ileum).
This toxin is used, as Prof Cummins notes, in millions of acres of food crops approved for human consumption.
Dr Arpad Pusztai, who was already aware of this study, sent ngin the following comments which are obviously of particular interest, coming as they do not just from a leading nutritionist but a world-leading authority on lectins (the Bt toxin is a lectin):
As I have said time and time again, the first main target of any food, including GM food, is the digestive system. Thus, as in our Lancet paper, this ought to be the first main concern in any food testing programme. One thing this paper has definitely established (a point again I have made previously) is that as the Bt toxin is a Gal/GalNAc-specific lectin, it is inconceivable, from my experience with lectins, that it would not survive during its passage through the gut and then not react with the epithelium. I am glad to say, that both predictions were confirmed by these two Egyptian scientists. Incidentally, there are now 3 papers, and the FLAVR SAVR tomato study by the FDA, which established gut damage of one sort or another (see the Lancet, our J. Nutr. paper on GM peas and this Nat. Toxins paper). How long will it be before even the GM biotechnology industry will take notice of these?
On 30 Dec 2000, at 13:18, jcummins wrote:
The article below provides disturbing evidence that regulators in US and Canada select evidence supporting safety of GM crops and ignore good evidence of injury. Bt Cry 1 is used in millions of acres of food crops approved for human consumption. The evidence below that the Bt Cry 1 damages the ileum is very clear and should not have been ignored. After the abstract I have included discussion of the ileum. The damaged ileum would cause distress to digestion and is likely diagnosed as mild food poisoning or flu. The fact that GM crops are unlabelled means that the problems people experience after consuming GM food cannot be recognized and treated. What I am saying is that cry 9 was approved for animals because of its evident allergenicity in rats. The evidence that cry 1 (which was approved for human consumption) damaged the ileum was hidden from consumers!
Natural Toxins Volume 6, Issue 6, 1998. Pages: 219-233 Published Online: 29 Jun 1999 Research Article
Fine Structural Changes in the Ileum of Mice Fed on -Endotoxin- Treated Potatoes and Transgenic Potatoes
Abstract The present work has been designed to study the effect of feeding on transgenic potatoes, which carry the CryI gene of Bacillus thuringiensis var. kurstaki strain HD1, on the light and electron microscopic structure of the mice ileum, in comparison with feeding on potatoes treated with the -endotoxin isolated from the same bacterial strain. The microscopic architecture of the enterocytes of the ileum of both groups of mice revealed certain common features such as the appearance of mitochondria with signs of degeneration and disrupted short microvilli at the luminal surface. However, in the group of mice fed on the -endotoxin, several villi appeared with an abnormally large number of enterocytes (151.8 in control group versus 197 and 155.8 in endotoxin and transgenic-treated groups, respectively). Fifty percent of these cells were hypertrophied and multinucleated. The mean area of enterocyte was significantly increased (105.3 µm2 in control group versus 165.4 µm2 and 116.5 µm2 in endotoxin and transgenic-treated groups, respectively). Several forms of secondary lysosomes or auotophagic vacuoles were recognized in these cells. These changes were confirmed with the scanning electron microscope which revealed a remarkable increase in the topographic contour of enterocytes (23 µm in control group versus 44 µm and 28 µm in endotoxin and transgenic-treated groups, respectively) at the divulged surface of the villi. The basal lamina along the base of the enterocytes was damaged at several foci. Several disrupted microvilli appeared in association with variable-shaped cytoplasmic fragments. Some of these fragments contained endoplasmic reticulum, as well as ring-shaped annulate lamellae. In addition, the Paneth cells were highly activated and contained a large number of secretory granules. These changes may suggest that -endotoxin-treated potatoes resulted in the development of hyperplastic cells in the mice ileum. Although mild changes are reported in the structural configuration of the ileum of mice fed on transgenic potatoes, nevertheless, thorough tests of these new types of genetically engineered crops must be made to avoid the risks before marketing.
Copyright © 1998 John Wiley & Sons, Ltd.
Ileum final and longest segment of the small intestine. It is specifically responsible for the absorption of vitamin B12 and the reabsorption of conjugated bile salts . The ileum is about 4 m (13 feet) in length and extends from the jejunum (the middle section of the small intestine) to the ileocecal valve, which empties into the colon (large intestine). The ileum is suspended from the abdominal wall by the mesentery. The smooth muscle of the ileum's walls is thinner than the walls of other parts of the intestines, and its peristaltic contractions are slower. The ileum's lining is also less permeable than that of the upper small intestine. Small collections of lymphatic tissue (Peyer's patches) are embedded in the ileal wall, and specific receptors for bile salts and vitamin B12 are contained exclusively in its lining; about 90 percent of the conjugated bile salts in the intestinal contents is absorbed by the ileum.