A glass of wine a day can reduce the risk of the most common type of stroke by 10 per cent, researchers say.

Moderate drinking was found to help protect against the condition, in a study which the scientists admit is ‘controversial’.

A small glass of red wine, or any drink of less than 1.5 units, is thought to cut levels of a protein that forms blood clots.

Those who drank this amount were 10 per cent less likely to have an ischaemic stroke, where a clot cuts off oxygen and blood to the brain, forcing many sufferers to re-learn how to walk and talk.

Even up to two drinks a day, which could include almost two bottles of beer, was found by researchers in Cambridge and Sweden to cut the risk by 8 per cent.

More than 150,000 Britons a year suffer a stroke. Of these, 85 per cent are ischaemic.

The scientists, who examined 27 studies, involving more than 21,000 stroke victims, pointed out drinking heavily still raises stroke risk. But they said small amounts may improve health by increasing ‘good’ cholesterol.

Author Dr Susanna Larsson, of the Karolinska Institute near Stockholm, said: ‘Previous research has found an association between alcohol and lower levels of fibrinogen – a protein which helps the formation of blood clots.