A detailed investigation by the Royal Society, Britain's de facto national academy of sciences, found that the claims made by Arpad Pusztai, the scientist who sparked the current furore over GM food, are insupportable and defective.
A team of experts who analysed the fine detail of Dr Pusztai's research involving rats fed GM potatoes found no evidence to justify his claims that the public are being used as guinea pigs in a mass experiment.
Dr Pusztai, 69, who worked at the government-funded Rowett Research Institute in Aberdeen for 37 years until he was suspended last year after an interview with the World in Action television programme, is effectively discredited by the unprecedented nature of the Royal Society's damning conclusions.
"On the basis of the information available to us, it appears that the reported work from the Rowett is flawed in many aspects of design, execution and analysis and that no conclusions should be drawn from it," says a report of a Royal Society working party.
Dr Pusztai claimed that rats fed GM potatoes suffered ill- effects such as damaged immune systems, stunted internal organs and defective brain development. The results were eagerly taken up by environmentalists and others concerned at the introduction of GM crops and food.
Faced with the immense publicity and concern generated by Dr Pusztai's findings - the first to show potential health dangers from GM food - the Royal Society decided to take the unusual step of investigating the research of an individual scientist.
It appointed six independent experts in different disciplines, from statistics to immunology, to study the validity of Dr Pusztai's work. All of them found serious defects in the research, which they reported to a working party chaired by Professor Noreen Murray of the University of Edinburgh.
"We found no convincing evidence of adverse effects from GM potatoes. Where the data seemed to show slight differences between rats fed predominantly on GM and on non-GM potatoes, the differences were uninterpretable because of the technical limitations of the experiments and the incorrect use of statistical tests," the working party reports.
"In short, it was a dog's dinner," said Dr Jim Smith, a member of the working party and a senior scientist at the National Institute for Medical Research.
Professor Patrick Bateson, a vice-president of the Royal Society, said yesterday that the full council of the society has endorsed the findings of the working party, which concluded that Dr Pusztai's work concerned only one animal species, one type of food inserted with one gene using one particular GM technique.
"However skilfully the experiments were done, it would be unjustifiable to draw from them general conclusions about whether genetically modified foods are harmful to human beings or not. Each GM food must be assessed individually," Professor Bateson said.
One of the most startling claims made by Dr Pusztai - that the GM potatoes used in the experiment affected the rats' immune systems - was dismissed by experts in statistics who said his interpretation did not "stand up".
"Inappropriate statistical tests had been applied to the data and, when the appropriate comparisons are made, there are no interpretable differences," the working party's report found.
Professor Bateson said Dr Pusztai was offered the opportunity of replying to the Royal Society's report but he declined. "He has indicated that further data existed but he regrettably has not provided it," Professor Bateson said.
The Royal Society said that although Dr Pusztai's research failed to show any ill-effects of GM food, this does not mean that harmful effects can be ruled out. It recommended further research, carried out to a high standard and with the full use of existing regulations to ensure the safety of food.
Dr Pusztai was unavailable for comment.
t Jack Cunningham, the Minister for the Cabinet Office, is planning to make a statement on the Royal Society's findings in the House of Commons tomorrow, writes Colin Brown.
The statement is also intended to clarify the Government's policy after criticism that it has been dogged by confusion and splits over the issue of genetically modified crops and food.
Cabinet ministers are privately critical of the confusion caused by anti- GM remarks made by Michael Meacher, an Environment minister, and assurances given on GM foods by Jeff Rooker, an Agriculture minister.
Mr Cunningham, a former Minister of Agriculture, will defend the Government's go-ahead for GM crop trials and attempt to allay some of the fears caused by scares over genetically modified foods.Reuse content