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A kindergarten class at a bilingual school in Oregon.
Principal Paco Furlan helps kindergarten students at a bilingual school in Eugene, Oregon (file photo).

Photograph by Chris Pietsch, The Register-Guard/AP

Christine Dell'Amore

National Geographic News

Published February 18, 2011

Talk about the power of words—speaking at least two languages may slow dementia in the aging brain, new research shows.

Scientists already knew that bilingual young adults and children perform better on tasks dictated by the brain's executive control system.

Located at the front of the brain, this system is "the basis for your ability to think in complex ways, control attention, and do everything we think of as uniquely human thought," said Ellen Bialystok, a psychologist at York University in Toronto, Canada.

Now studies are revealing that advantages of bilingualism persist into old age, even as the brain's sharpness naturally declines, Bialystok said Friday at a meeting of the American Association for the Advancement of Science in Washington, D.C.

(See "Cell Phone Use May Fight Alzheimer's, Mouse Study Says.")

Bilingual Brains Delay Aging Effects

Bialystok and colleagues examined 102 longtime bilingual and 109 monolingual Alzheimer's patients who had the same level of mental acuity. About 24 million people have dementia worldwide, with the majority of them suffering from Alzheimer's, according to Sweden's Karolinska Institutet medical university.

The bilingual patients had been diagnosed with the Alzheimer's about four years later than the monolingual patients, on average, according to Bialystok's most recent study, published in November in the journal Neurology.

This suggests bilingualism is "protecting older adults, even as Alzheimer's is beginning to affect cognitive function," Bialystok said. (Take a brain quiz.)

Bialystok is also studying physical differences between bilingual and monolingual brains.

In a new experiment, she used CT scans to examine brains of monolinguals and bilinguals with dementia. All the subjects were the same age and functioned at the same cognitive level.

The physical effects of the disease in the brain were found to be more advanced in the bilinguals' brains, even though their mental ability was roughly the same, Bialystok told National Geographic News.

Apparently, the bilinguals' brains are somehow compensating, she said. "Even though the 'machine' is more broken, they can function at the same level as a monolingual with less disease," she said.

Not Too Late to Benefit From a New Language

Benefits of bilingualism can begin in utero, Janet Werker, a psychologist at the University of British Columbia, Canada, told the news briefing.

For instance, Werker and colleagues' recent studies show that babies exposed to two languages in utero do not confuse their languages from birth.

The mental workout required to keep the languages separate may create an "enhanced perceptual vigilance" that has lifelong benefits, Werker said.

"What I'd like to suggest is the kind of advantages you've heard about [in aging] can be established from those first days of life, in [babies] having to keep the two languages apart."

Granted, people born into bilingualism have it a bit easier.

"One of the things babies have is the luxury of time—they get the opportunity to really focus on task at hand," Werker said.

"If we want to learn a second language, [we need to] set time aside to allow that to happen"—and evidence suggests the payoff is worth it.

Even if you don’t learn a second language until after middle age, it can still help stave off dementia, York's Bialystok said.

Being "bilingual is one way to keep your brain active—it's part of the cognitive-reserve approach to brain fitness," Bialystok said.

And when it comes to exercising the brain by learning another language, she added, "the more the better—and every little bit helps."

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