ngin - Norfolk Genetic Information Network

excerpt from 'Response to GM myths'/Dr Roger Morton to AgBioView - 12/12/00:

[Dr Morton quotes from a document called 'GM myths' and then responds]


"One of the few published reports with experimental data tells of GM  potatoes, modified to contain a lectin, which were found to have toxic effects on rats' organs, including the brain and the immune system. Similar tests on rats using non-modified potatoes turned up no such results."

Morton's comment:

These potatoes were not in the process of being commercialized and have not been continued with. All this data shows is that testing GM foods works. You can spot possible problems using animal tests.

What the activists won't tell you is that Dr Puztai has other publications which conclude: Pusztai A, Grant G, Bardócz S, Alonso R, Chrispeels MJ, Schroeder HE, Tabe LM, Higgins TJV (1999) Expression of insecticidal bean a-amylase inhibitor transgene has minimal detrimental effect on the nutritional value of peas in the rat at 30% of the diet.  J Nutr 129:1597-1603 The effect of expression of bean alpha-amylase inhibitor (alpha-AI) transgene on the nutritional value of peas has been evaluated by pair- feeding rats diets containing transgenic or parent peas at 300 and 650 g/kg, respectively, and at 150 g protein/kg diet, supplemented with essential amino acids to target requirements. The results were also compared with the effects of diets containing lactalbumin with or without 0.9 or 2.0 mg bean alpha-AI, levels equivalent to those in transgenic pea diets. When 300 and 650 g peas/kg diet were fed, the daily intake of alpha-AI was 11.5 or 26.3 mg alpha-AI, respectively. At the 300 g/kg level, the nutritional value of the transgenic and parent line peas was not significantly different. The weight gain and tissue weights of rats fed either of the two pea diets were not significantly different from each other or from those of rats given the lactalbumin diet even when this was supplemented with 0.9 g alpha-AI/kg. The digestibilities of protein and dry matter of the pea diets were slightly but significantly lower than those of the lactalbumin diet, probably due to the presence of naturally occurring antinutrients in peas. The differences between transgenic and parent pea lines were small, possibly because neither the purified recombinant alpha-AI nor that in transgenic peas inhibited starch digestion in the rat small intestine in vivo to the same extent as did bean alpha-AI.

Thus, this short-term study indicated that transgenic peas expressing bean alpha-AI gene could be used in rat diets at 300 g/kg level without major harmful effects on their growth, metabolism and health, raising the possibility that transgenic peas may also be used at this level in the diet of farm animals.


"The researcher, Dr Arpad Pusztai, lost his job after he mentioned the experiment during a television interview. His critics claim his work was never peer-reviewed -- yet the survey reported in Science also found that none of the articles published by biotechnology companies were  peer-reviewed either.

Morton's comment:

This is a not true. Look at the bibliography and you will see the vast majority of the publications mentioned are full peer-reviewed publications in journals [added emphasis]. Some reports submitted to FDA, EPA etc are not peer reviewed by journal editors but you can be sure they are peer reviewed by the people at FDA and EPA. Might I also point out that a letter to Science is not peer reviewed and it is quite possible that the author of the letter quoted here is completely wrong. The bibliography  shows that he is in fact wrong.