A second language can be a big advantage in many ways – whether you’re looking for a new job or want to blend in with the locals on a foreign holiday. But could it also sharpen your brain and help keep it young?

A fascinating study published in the Journal of Neuroscience found a connection between faster mental reactions and speaking two or more languages. They found that people who were raised bilingual may have brains that work more efficiently. As they age, their linguistic abilities could help delay a decline in brain power.

The team of neurobiologists at the University of Kentucky studied two groups of younger and older people, asking them to switch rapidly between two tasks. In each group, half the subjects had been bilingual since childhood, while the rest were monolingual. They found both the younger groups performed equally well. But among the older subjects, the bilingual people had faster reaction times.

Dr Brian Gold, who led the research, speculated that since bilingual people are used to switching between languages in their daily lives, their brains might be more efficient at switching between other tasks. Other research has supported the theory that bilingualism could sometimes help delay the onset of dementia.

In another study, researchers at Northwestern University, in Chicago, found that bilingual student volunteers found it easier to filter out distracting sounds and concentrate on a speaker. They suggested this is because their brains are used to suppressing the language they’re not using at the time.

It appears that knowing more than one language might have more benefits than we thought.  Around 20 per cent of the US population is bilingual, with the most commonly spoken languages after English being Spanish, Chinese, French, and Tagalog. The percentage of bilingual Americans is rising, from around 11 per cent in 1980, although it’s still lower than Canada’s 35 per cent figure.

The bad news for adult learners is that most of this research has concentrated on people who have spoken two languages since childhood. Signing up for Spanish night school classes is unlikely to bring the same benefits!

However it’s certainly food for thought for anyone thinking of teaching their children a second language, or sending them to a bilingual school. In the past, some educators thought that bilingualism could be a disadvantage, and discouraged children from speaking two languages at school. But the evidence suggests that most children have little difficulty switching between languages, and it can translate into big benefits later in life. President Obama said at a rally in 2008 that he would like to see every child learn a second language.

And for older learners there are still plenty of reasons to dust off those French books or sign up for a Mandarin course. Languages can make your resume stand out from the crowd, as well as giving you a valuable insight into other cultures.