The likely benefits of ES cells and the speed with which they will help patients have been exaggerated to persuade politicians and the public to support this controversial field, Lord Winston, the fertility specialist and broadcaster, will say today.

Lord Winston, who is president of the British Association for the Advancement of Science (BA), believes that experiments with ES cells are important and could eventually lead to ground-breaking advances in medicine and biology.

He is concerned, however, that these have been hyped for political reasons, and that there will be a backlash against ES research when it fails to provide new treatments for Parkinson’s disease, diabetes and other illnesses within the next few years.

In his address today at the BA’s annual Festival of Science in Dublin, he will urge scientists not to overstate the importance of their work. “We do tend to hype up some areas of science, and the latest example in biology is embryonic stem cells,” he said yesterday. “I view the current wave of opinion about embryonic stem cells with growing suspicion.

“I am very clear that I think the focus on stem-cell biology is a very important focus. I don’t doubt for a moment that we should study embryonic stem cells and that they are going to communicate a great deal about cell growth and biology.

“But I think that in our desperation to get quite proper legislation on the books, I’m concerned that some politicians are convinced that it’s just a matter of a few years before we are transferring stem cells to cure diseases such as Alzheimer’s, and that’s going to be a huge problem.

“If we run at this too hard and start saying we’re going to have cures for diabetes, Parkinson’s, Alzheimer’s, there’s going to be an almighty backlash, not least from pro-life groups that will perceive the chink in our armour.”

But Professor Stephen Minger, of King’s College London, who created Britain’s first colony of ES cells, said: “There has been hype in the field, but it has not been the scientists who have been responsible for it. None of us is claiming that therapies are going to be with us tomorrow, and I think it’s irresponsible to say everything is driven by hype.

“It is true that Alzheimer’s is not a promising candidate for stem-cell therapies, but it was not scientists who suggested it was — that was all politics in the US driven by Nancy Reagan. This field is really a nascent one, I think the public here understands that, and I think he’s overreacting. I get ten phone calls a week from desperate patients and the last thing I want to do is sell them hype and false hope.”

Lord Winston aired his concerns as scientists today publish a study showing that colonies of human ES cells can accumulate genetic changes that could affect their behaviour. The study in Nature Genetics, led by Aravinda Chakravarti, of Johns Hopkins University in Baltimore, Maryland, underlines the need for careful testing before the cells can be used in medical therapies.

Some of the DNA changes are typical of those seen in some cancers. This suggests a risk to transplanting them into patients, though it could also give scientists an insight into tumour development.

ES cells are master cells that can give rise to any form of tissue in the human body, and might thus be used to grow replacements for the cells that are lost or damaged in conditions such as diabetes, Parkinson’s and spinal injury.

MEDICAL DRAMA

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