Speaking more than one language has a number of practical benefits in an increasingly globalized world, but science shows it may also help your health.
Recent research has found bilingualism may delay the onset of Alzheimer's disease, and now a new study published in the American Heart Association journal Stroke shows that speaking multiple languages may help protect the brain after a stroke.
Bilingual patients in the study were twice as likely to have normal cognitive functions after a stroke as those who spoke only one language.
Researchers from Nizam's Institute of Medical Sciences (NIMS) in India and the University of Edinburgh in the U.K. studied records of over 600 stroke patients in Hyderabad, India, a city in which multiple languages are commonly spoken.
An analysis showed that about 40 percent of the bilingual patients retained normal cognitive function following a stroke, compared to 20 percent of those who spoke a single language.
The bilingual patients performed better on post-stroke tests that measured attention and ability to retrieve and organize information.
The researchers said the study suggests that years of switching back and forth from one language to another enhances the development of executive function in the brain, offering protective benefits against cognitive impairment after a stroke.
"The advantage of bilingualism is that it makes people switch from one language to another, so while they inhibit one language, they have to activate another to communicate," lead study author Suvarna Alladi, a neurology professor at NIMS, said in a statement.
To ensure that lifestyle factors weren't at play, the researchers took into account smoking, high blood pressure, diabetes and age.
But the researchers also found something unexpected. Bilingual patients were just as likely as single-language speakers to experience aphasia, an impairment of language ability that can cause difficulties in speaking, reading and writing after a stroke.
"The combined vocabulary of bilinguals can make it more difficult for them to find specific words. This may explain what appears to be a surprising result," Dr. Thomas Bak, study co-author at the University of Edinburgh, explained.
The authors noted that the findings may not be applicable to all bilingual people, as Hyderabad encompasses many cultures and multiple languages are commonly spoken, including Telugu, Urdu, Hindi and English.
"Constantly switching languages is a daily reality for many residents of Hyderabad," Alladi said. "The cognitive benefit may not be seen in places where the need to function in two or more languages isn't as extensive."
And although this research is good news for bilingual people, it doesn't necessarily mean those who only speak one language should try to learn another for health reasons. "Our study suggests that intellectually stimulating activities pursued over time, from a young age or even starting in mid-life, can protect you from the damage brought on by a stroke," Subhash Kaul, senior investigator and developer of the stroke registry at NIMS said.