Scientists revolt at publication of 'flawed' GM study

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The Independent Online

THE STUDY that sparked the furore over genetically modified food has failed the ultimate test of scientific credibility.

THE STUDY that sparked the furore over genetically modified food has failed the ultimate test of scientific credibility.

Research purporting to show that rats suffer ill-health when fed GM potatoes has been judged as seriously flawed and unworthy of being published by a peer-reviewed scientific journal.

Referees used by The Lancet , one of Britain's leading medical journals, to review the research have found that it has failed to prove a link between GM potatoes and intestinal disorders in the rats.

The referees - all experts in their own fields who judged the work independently of each other - found the study to be defective in design, execution and interpretation.

Despite their assessments, however, The Lancet has decided to go ahead and publish the study this week, on the grounds that publication of even flawed research could be in the public interest.

However its editor, Richard Horton, faces a revolt by his own referees - who usually remain anonymous - if he does not make it clear that the results of the study by Dr Arpad Pusztai and Professor Stanley Ewen was deemed to be deeply flawed and its conclusions highly speculative and unsubstantiated.

One referee, Professor John Pickett, an authority on plant chemistry, is so outraged by the journal that he has decided to voice his concerns in public.

"It is a very sad day when a very distinguished journal of this kind sees fit to go against senior reviewers," said Professor Pickett, the head of biological and ecological chemistry at the government's Institute of Arable Crops Research at Rothamsted near Harpenden in Hertfordshire.

Another Lancet referee, who wished to remain anonymous, said it would be wrong to publish the conclusions of Dr Pusztai and Professor Ewen because they amount to "wild speculation" which cannot be supported by the data.

Professor Ewen, a pathologist at the University of Aberdeen, and Dr Pusztai, who worked on plant toxins at the nearby Rowett Research Institute before retiring last year, claim that the intestinal linings of rats fed GM potatoes become thickened and inflamed, which they did not observe in control rats fed ordinary potatoes.

However, The Lancet 's referees strongly dissented from these conclusions. "The only thing they have shown is that rats fed raw potatoes do not do very well. It has nothing to do with GM, it is simply that raw potatoes are not very nutritious," said one.

Professor Pickett agreed: "I had seen the data and how inadequate it was in terms of tackling the question in hand. I was very critical of the work because it is a shambles really. Rats don't eat raw potatoes very well and half way through they realised this and decided to boil the potatoes."

Another reviewer found that the statistics used by Professor Ewen and Dr Pusztai were inadequate, that their methodology was flawed and their analysis incorrect. "If this was a PhD thesis, I'd reject it," he said.

The fact that The Lancet intends to publish the research has been hailed by environmentalists as dramatic vindication of Dr Pusztai's claims about the health effects of GM food. However, the Royal Society, the eminent body of scientists, is preparing this week to counter the claims that publication in The Lancet confers respectability.

"If they publish without any disclaimer or without making clear the reservations of the reviewers then we would take a very serious view of it," said Steven Cox, the Royal Society's executive secretary.

John Gatehouse, a scientist at Durham University who once worked with Dr Pusztai on the rat experiments, has written to The Lancet expressing his concerns about the "unsupported assertions" and "anecdotal" nature of the results. He says the conclusion that GM plants cause some undefined health problem is "simply unscientific; it is the attitude of the medieval witchcraft trials".

Another scientist who has seen the research, Professor Martin Chrispeels of the University of California at San Diego, said: "This isn't science. It wouldn't be published in a serious plant biology journal. Their conclusion is not correct."

Professor Ewen said that if his paper has been accepted for publication then it must mean that the referees' criticisms have been addressed. "Before a paper is published you will have to have satisfied the referees, that's a prerequisite." Professor Ewen said. "It is a matter for the editor of The Lancet . Why is he publishing it if he thinks that it hasn't satisfied the referees?"

Dr Horton was unavailable for comment.