Stroke patients are more likely to regain their cognitive functions if they speak more than one language, new research has discovered.
A study of more than 600 stroke victims found 40.5% of those who are multilingual had normal mental functions afterwards, compared to 19.6% of patients who only speak one language.
The study was carried out by a team from the University of Edinburgh together with the Nizam Institute of Medical Sciences in Hyderabad - with the Indian city chosen as the location for the study because its multi-cultural nature means many languages are commonly spoken.
Researchers took into account other factors such as smoking, high blood pressure, diabetes and age to ensure results could not be attributed to having a healthier lifestyle.
The study, published in the American Heart Association journal Stroke, found 'results support the notion of a protective role of bilingualism in the development of post-stroke cognitive impairment'.
It is the first time a study has been done looking at the relationship between the number of languages spoken and a patient's cognitive outcome after stroke.
'The percentage of patients with intact cognitive functions post-stroke was more than twice as high in bilinguals than in monolinguals,' the paper said.
'In contrast, patients with cognitive impairment were more common in monolinguals.'
Researchers believe the study, which was funded by the Indian Council of Medical Research, suggests the mental challenge of speaking multiple languages can boost cognitive reserve - an improved ability of the brain to cope with damaging influences such as stroke or dementia.
Co-author Thomas Bak, of the University of Edinburgh's school of philosophy, psychology and language sciences said: 'Bilingualism makes people switch from one language to another, so while they inhibit one language, they have to activate another to communicate.
'This switching offers practically constant brain training which may be a factor in helping stroke patients recover.'