The study was presented as an abstract at a conference in Austria, and did not represent published research.
Prof Chris Leaver, Professor of Plant Sciences, University of Oxford, said:
“Many animal studies, including multigenerational ones, have been done on gm maize and none has revealed any differences between test- and control-fed animals. That being the case, when a new study finds something different, science must be given the opportunity to examine the causes for difference which can be many (problems with feed, non comparable designs, and on and on). No conclusion about safety should be drawn until the reasons for the deviation from previously publications are understood.
“Insect protected maize has been grown widely in a number of countries. A major use is animal feed. No reports of changes in reproductive performance, or any other parameter, have emerged in spite of 10 years of planting on millions of hectares. I would stress that until the full report is published it is irresponsible to call this news.”
Prof Derek Burke, former Vice-Chancellor of the University of East Anglia, said:
“The claims in this paper are very modest and the authors themselves are extremely cautious. There is a long history of claims that feeding GM foods to animals causes physiological damage; these invariably turn out, after extensive and expensive investigation, to be worthless.
“In general extreme caution has to be exercised about such feeding trials. They have to be large groups which are carefully matched, and it is very important that the substance that is offered is part of the normal diet and is not present in higher amounts than it would be in the normal diet. Herein lies the rub. If you don’t increase the dose above that which is normal it’s very hard to get any effect at all; if you do increase the dose above that which is normal, you get nonspecific toxic effects.
“In the USA, GM soya has been eaten extensively for more than 10 years; and in the most litigious society in the world, no one has ever successfully brought any action for damage. It is very unwise to draw generalised conclusions from any work which has not been through the proper refereeing process.”
Prof Ian Crute, Institute Director of Rothamsted Research, said:
“These experiments are definitely not an examination of the safety or otherwise of GM technology per se. Clarity here is important. It is the traits in question (i.e. proteins conferring the characteristics of insect and herbicide resistance on maize) and not the means of their delivery to the plant (i.e. genetic transformation) which have purportedly shown some effects.”