The benefits of knowing more than one language are apparent for travel and work. Yet, a little-known benefit is that being bilingual can increase a person’s mental health.

A 2006 Canadian study, Bilingualism as a protection against the onset of symptoms of dementia, examined the medical records of a group of 184 seniors diagnosed with dementia, 51 per cent of whom were bilingual.

The onset of dementia symptoms in the bilingual group was four years later than the monolingual group.

In an interview with the CBC Radio program, C’est la Vie, Fergus Craik — a researcher who participated in the study — gave a theory to support these results.

“Our speculation is that this constant need to inhibit the non-used language is what carries over . . . is what gives bilinguals an advantage in a number of other executive processes,” he said.

It’s “the ability to screen out what’s irrelevant information and focus on the things we’re supposed to be focusing on.”

Piet Van de Craen is a professor of general linguistics at the Vrije Universiteit Brussel. He participated in a 2011 study, Neural Differences in Bilingual Children’s Arithmetic Processing Depending on Language of Instruction, which looked at the ability of bilingual students to solve math problems based on which language they used. The children who used the language they were taught in school, as opposed to their home language, solved the problems using less brain activity.

It’s not simply about being able to speak more than one language, but being educated in both languages, according to Van de Craen.

“The brains of young multilingual children are differently organized, and there are cognitive advantages of learning in two languages. From there, we can maybe derive the conclusion that to make your brain stronger, it is good to study in two languages. If you have a stronger brain, then maybe the onset [of dementia] is delayed.”

Van de Craen also drew comparisons between the benefits of being educated in an immersion setting and learning to play an instrument.
“It’s all about learning and creating connections in the brain,” said Van de Craen.

“If you want to become a great piano player, you better learn early in life. It’s logical that the [mental] benefits are greater if you start early.