Two languages are better than one when it comes to keeping the brain young, Canadian researchers reported on Monday.

Older adults who grew up bilingual had quicker minds when tested than people who spoke only one language, the researchers found. They showed less of the natural decline associated with aging.

The tests of people who grew up speaking English and either Tamil or French suggested that having to juggle two languages keeps the brain elastic and may help prevent some of the mental slowing caused by age, the researchers said.

Writing in the journal Psychology and Aging, Ellen Bialystok of York University in Canada and colleagues said they tested 104 monolingual and bilingual middle-aged adults aged 30 to 59 and 50 older adults aged 60 to 88.

They used a test called the Simon Task, which measures reaction time for cognitive tasks, such as recognizing on which part of a computer screen a colored square appears.

Both younger and older bilinguals were faster on the test, Bialystok reported.

“We compared groups of people who, as far as we could tell, are exactly the same,” Bialystok said in a telephone interview.

“They have all had the same amount of education. They all scored exactly the same on cognitive tests. They all perform the same on memory tests. And they also score the same on tests in English vocabulary.”

The difference was that half the people grew up with either French or Tamil spoken at home and English outside. They all spoke both languages every day from childhood.

People who were proficient in a second language acquired in school were not included in the study to keep the effects clear.

“It’s not a facility. It’s not a talent,” Bialystok said. Rather it was a case of being forced from a young age to function in two languages.

Bialystok said her earlier study with children suggested these circumstances force a change in the way the brain processes information.

“In the monolingual group the differences between the younger adults and the older adults were in line with (the decline seen) in previous research,” Bialystok said.

“In the older bilingual they slowed down significantly less, dramatically less.”

Bialystok has not tested people who acquired languages later in life but believes learning new languages can only be good for the brain. “Language is always good - more language is always better,” she said.

SOURCE: Psychology and Aging, June 2004.