A breathing technique for asthma sufferers developed 40 years ago has been proved for the first time to cut symptoms of breathlessness by a third. The Papworth method is a sequence of breathing and relaxation exercises devised at Papworth hospital, Cambridgeshire, in the 1960s. Patients and physiotherapists believed it worked, but it fell out of favour among Britain's five million asthma sufferers who came to rely on medication.

Now, researchers have demonstrated its effectiveness in what is believed to be the first randomised, controlled trial of the method - the gold standard in medical research. The technique is aimed at curbing over-breathing - the rapid shallow breaths at the top of the chest taken by people when they are under stress. The aim is to encourage gentler, more relaxed breathing, using the abdomen and diaphragm rather than the chest.

Elizabeth Holloway, a research physiotherapist with more than 30 years' clinical experience, who led the study, said: It is about breathing like Richard Burton [the Welsh actor] who delivered his lines from deep down in his abdomen. It is not just psychological, it is physical - patients need to learn to drop their shoulders, relax their tummies and breathe calmly and appropriately. They gain greater control and confidence.

Eighty-five asthma patients in a GP practice in Welwyn, Hertfordhsire, were randomly allocated to receive five one-hour training sessions in the method. All the patients continued to use their usual inhaler or other medication and their responses were compared. The results, published in Thorax, showed that those taught the Papworth method had symptom scores of 21.

8 on average, one third lower than those who received medication only whose average symptom score was 32.8. Ms Holloway, who learnt the method herself at Papworth, said: Some of us who use it know it works but there was no scientific evidence.

That is why I did the study. Younger doctors don't know about it - over the last several decades the emphasis has been on medication. Professor Martyn Partridge, medical adviser to Asthma UK, said studies of breathing techniques had shown success in improving symptoms, but he urged caution.

I have a certain sympathy with the view that there is an over-reliance on prescription medicine in response to this condition. But the people in whom these methods help tend to have other problems of over-breathing and are those in whom asthma is not the main problem. A study of transcendental meditation conducted in India has revealed changes in the irritation of the airways, providing further proof of the multiple influences on the symptoms.

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