THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE

15 September 2003

Dear friends and colleagues,

RE: PUSZTAI’S REVIEW ENFORCES WARNINGS ON GE FOODS

Arpad Pusztai, the scientist who first stunned the world with research claiming that GM crops might damage human health (and who lost his job as a result), has released new findings that further support his early warnings.

Dr. Pusztai said that the work carried out by biotechnology companies on the human health hazard from GM food is inadequate. He said to date there have never been any human clinical trials conducted on GM food. Most attempts to establish the safety of GM food have been indirect and there is absolutely nothing known about the potential hazards (if any) for human health of indirect exposure to GM foods such as through consumption of animals fed on GM food.

In a chapter published in a book on food safety, he brought together all the scientific studies carried out into the safety of GM foods and subjects them to rigorous statistical and scientific scrutiny.

Though he found most of the studies were inadequate and wanting in terms of the quality expected, he nonetheless were able to find that some existing studies support the early warnings he expressed from his own research in which he found rats fed on GM potatoes suffered a weakened immune system as well as severe impairment in the development of the internal organs. He concluded that “the present crude method of genetic modification has not delivered GM crops that are predictably safe and wholesome.”

Some of the conclusions that could be drawn from his review of the existing studies - both peer-reviewed as well as non-peer reviewed but have implications for regulations - are as follow:

In a feeding experiment commissioned by Calgene for the US Food and Drug Administration (FDA) involving GM tomatoes (Flavr Savr) to rats, seven out of 40 rats which ate GM tomatoes died within 2 weeks. The nature of these deaths was not specified in the study but the evidence that they were not related to the ingestion of transgenic tomatoes was inconclusive.

The conclusion from the Flavr Savr experiment that feeding rats on GM tomatoes for 28 days had no effect on weight gain, feed intake and organ weights could not be justified because the starting weights of the rats were so widely different that finding significance differences in weight gain, feed intake and organ weights was not likely. The FDA conclusion that Flavr Savr presented no more dangers to consumers than ordinary tomatoes therefore does not appear to rest on good science.

With regards to evidence presented by Aventis for the two lines of Chardon LL herbicide-resistant GM maize seed to establish their substantial equivalence to the conventional parent maize line, the company did not specify the origin and conditions of cultivation of the different GM and non-GM samples and therefore strict scientific comparisons could not be made between them. However, even under these conditions, the two lines of GM maize expressing the socalled PAT-PROTEIN showed many statistically significant differences in fat and carbohydrate contents in comparison with the non-GM grain samples, and fat, protein and fibre between silage samples from GM and non-GM maize. Thus, the conclusion that GM maize is not “materially different” from current commercial varieties cannot be regarded as valid.

An experiment was also conducted whereby PAT-PROTEIN was given to rats for 14 days to assess the cumulative toxicity of the protein and to provide a rational basis for toxicological risk assessment in humans.  But the design and execution of the experiment was faulty therefore it is difficult to draw valid conclusions from the feeding study. The results therefore could not be taken as evidence that the transfer of its gene into maize represented no risk for the rat and by inference, for humans, particularly as no gut histology studies have been completed so far. In addition, a recent publication has showed that DNA survived in intact form or slightly fragmented unless the GM maize was heat processed extensively. Therefore, the possibility exists that with underprocessed maize products, humans and animals might be exposed to the DNA used in genetic engineering.

On the publications establishing the compositional “substantial equivalence” of GM and non-GM soya, it has been found, on closer study of the data, that the statistical comparison of the macronutrients of GM and non-GM lines was not scientifically valid. Pusztai found that there is insufficient evidence to date to decide whether the composition of GM and conventional soybeans is equivalent or not. Because not strictly comparable compositional data were used, the case for equivalence was not properly established.

Milk production and composition and performance data in the lactating cow study showed some significant differences between cows fed diets containing the different lines of soybean, indicating a lack of “substantial equivalence”.

In a main histology study carried out on the ileum of mice fed with potatoes transformed with a Bt var.kurstaki Cry1 toxic gene, it was established that, in contrast to general belief, exposure of the mouse gut (ileum) to the Cry1 gene product has caused profound hypertrophic and hyperplastic changes in cells of the gut absorptive epithelium and can lead to mucosal sensitization.    

The chapter, coauthored by Pusztai, together with S. Bardocz and S W B Ewen is found in the book “Food Safety: Contaminants and Toxins”, edited by J P F D’Mello of the Scottish Agricultural College in the UK and is available online at: http://www.cabi-publishing.org/Bookshop/ReadingRoom/0851996078.asp). 

With best wishes,

Lim Li Lin and Chee Yoke Heong

Third World Network

121-S Jalan Utama

10450 Penang

Malaysia

Email: twnet@po.jaring.my