Yoga breathing exercises could help sufferers of mild asthma and may help reduce their use of low-dose drug inhalers in wheezing attacks.
Researchers from the Respiratory Medicine Unit, City University, Nottingham, call for more studies of ways of improving breathing control which they say have been largely ignored by Western medicine.
While yoga practitioners have long believed in the benefits of pranayama breathing exercises for asthmatics, this has been hard to study formally. But, using a Pink City lung - a device that imposes slow breathing on the user and can mimic pranayama breathing exercises - it was possible to measure the effects of controlled breathing in a hospital trial.
Two simulated pranayama exercises were tested: slow deep breathing and breathing out for twice as long as breathing in.
In asthma, the airways become restricted making breathing difficult. It is increasing in the UK, with more than three million children and adults affected, and are responsible for 2,000 deaths annually.
The doctors used standard clinical tests to measure the volume of air patients were able to blow out in a second and to test the irritability of their airways. After yoga, their airways were two times less irritable,