London: Planning to join French classes? Here is a reason why you should go ahead with your plan – learning another language "rewires" the brain and could help slow the onset of dementia, claims a new study.
Researchers at the York University in Toronto, Canada, found that learning two languages makes the brain work harder, making it more resilient in later life.
For the study, the researchers led by Dr Ellen Bialystok looked at hospital records of dementia patients who were either monolingual or bilingual. It was found that bilingual patients were diagnosed with dementsia three to four years after those who spoke only one language.
"Specifically, monolingual patients were diagnosed on average at age 75.4 years and bilinguals at age 78.6 years," they wrote in the journal Trends in Cognitive Sciences.
"Previous studies have established that bilingualism has a beneficial effect on cognitive development in children. In our paper, we reviewed recent studies using both behavioural and neuroimaging methods to examine the effects of bilingualism on cognition in adults," they noted.
As lifelong bilingualism appeared to have the strongest protective effect, they said, any attempt at learning another language was likely to be beneficial, as reported.
"If bilingualism is protective against some forms of dementia, then middle-aged people will want to know whether it is too late to learn another language, or whether their high-school French will count towards coginitive reserve," they said.
In the study,     brain imaging scans have found that having to switch between two languages helps exercise parts of the brain that carry out taxing intellectual tasks, like multi-tasking and concentrating intensely on a subject for a sustained period of time.
These "executive control" functions tend to be among the first to wane in old age, a process known as "cognitive decline", Dr Bialystok said.    

"Our conclusion is that lifelong experience in managing attention to two languages reorganises specific brain networks, creating a more effective basis for executive control and sustaining better cognitive performance throughout our lifespan," Dr Bialystok commented.
Dr Marie Janson, of Alzheimer's Research UK, said: "We know there are several lifestyle factors -- such as healthy eating, exercise and mental activity -- that could help to reduce our risk of dementia.
"This review discusses the evidence that keeping our brains active by switching between different languages could help to resist some of the damage caused by dementia, delaying the onset of symptoms.
"More research is needed to tease apart the most beneficial aspects of bilingualism -- whether it is the age we starting learning, how fluent we are or how much we use the language in everyday life."