Scorn poured on genetic risk claim

CLAIMS THAT a strain of experimental genetically-modified (GM) potatoes might harm humans were shot down yesterday, as scientists pointed out that the potatoes would fail existing regulatory tests for modified foods.

The TV programme World in Action last night featured work by Professor Arpad Puztai, a specialist in nutrition, at the Rowett Research Institute in Aberdeen. The programme showed that laboratory rats fed with transgenic potatoes, containing specific genes from snowdrops and jackbean plants, had weaker immune system.

But John Gatehouse, who developed the potatoes at the University of Durham, said: "I'm not surprised. The genes that were added direct the manufacture of plant lectins which are harmful to insects. We know that they're toxic to insects, so it isn't shocking if they also have toxicity to animals. That was what we wanted to know, and that's why the tests were carried out."

Dr Gatehouse is providing plants samples for Professor Puztai as part of a pounds 700,000 project being funded by the Scottish Office to try to develop insect-resistant plant strains.

Presently there are only four GM food products on retailers' shelves: tomato puree, vegetarian cheese, maize and soya, though the latter is used in about 60 per cent of foods such as bread, biscuits and cakes. None uses genes like those added to the potatoes in the experiment. Dr Colin Merritt, technical manager of the biotechnology company Monsanto, said the result actually vindicated the existing regulatory process.

"There's a tremendous range of tests that have to be done.

"Our studies show that in the digestive system our added protein has a half-life of just 15 seconds before it is broken down into its constituent amino acids." At the amino acid level, there is no difference between transgenic and natural sources.

Dr Merritt added that the genes being added to the potatoes tested at the Rowett Institute were "in a different class from those used in commercial crops."

John Hammond, head of development at AgrEvo Crop UK, which is also developing GM crops, said: "The Rowett work is a bit unusual - they have taken a gene that generates a potentially quite potent insecticide and found it doesn't meet the safety criterion."

But the findings were seized on by some groups who are seeking a moratorium on the deployment of GM crops and foods in the UK. Liberal Democrat food spokesman Paul Tyler called on ministers to take action over the use of GM food before it was "too late", and said: "These reports should shake British ministers out of their complacency about the genetic engineering of our food."

However, the Food Minister Jeff Rooker rejected the call. "The potatoes have gone wrong because this particular potato damaged the immune system of the animals it was tested on. The fact is, that product wouldn't have got through the regulatory process to be allowed to be marketed as a product." He rejected calls for a moratorium: "I really can't say yes to that."

But Ian Gibson, a Labour MP who is a geneticist and a member of the Commons Science and Technology Committee, predicted that calls for a moratorium on GM products would increase over the next week.

"I think the Government is going to have to react very quickly and have a top flight meeting to decide on that issue - whether or not there should be a moratorium or not."

Dr Gibson stressed that his instinct was that there was more to be learned about protein constructs in plants and what they do to other plants.

"I'm beginning to get a bit nervous," he said. "I think they (the Government) should get together very quickly now and decide whether or not there should be a halt, or to reassure the public at least that this is `not for real' or `just a one-off'."