Learning another language 'rewires' the brain and could help delay the onset of dementia by years, research suggests.
Having to grapple with two languages makes the brain work harder, making it more resilient in later life, say academics.
One study found that, among people who did eventually get dementia, those who were bilingual throughout their lives developed the disease three to four years later.
Dr Ellen Bialystok, of York University in Toronto, Canada, and two colleagues examined hospital records of patients diagnosed with a variety of different types of dementia.
They found: "In spite of being equivalent on a variety of cognitive and other factors, the bilinguals experienced onset and symptoms and were diagnosed approximately three to four years later than the monolinguals.
"Specifically, monolingual patients were diagnosed on average at age 75.4 years and bilinguals at age 78.6 years.
Several other studies found similar results, they noted in the journal Trends in Cognitive Sciences.
While lifelong bilingualism appeared to have the strongest protective effect, any attempt at learning another language was likely to be beneficial, they wrote.
"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.
"A related question concerns the age of acquisition of a second language: is earlier better?" The best answer at present is that early age of acquisition, overall fluency, frequency of use, levels of literacy and grammatical accuracy all contribute to the bilingual advantage, with no single factor being decisive. "Increasing bilingualism" led to "increasing modification" of the brain, they said.
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 commented: "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 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.
"With 820,000 people in the UK living with dementia and this number expected to rise, it is vital to invest in research to understand more about how to prevent or delay the onset of this devastating condition." Original article from the Telegraph
While lifelong bilingualism appeared to have the strongest protective effect, any attempt at learning another language was likely to be beneficial, they wrote.
"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.
"A related question concerns the age of acquisition of a second language: is earlier better?" The best answer at present is that early age of acquisition, overall fluency, frequency of use, levels of literacy and grammatical accuracy all contribute to the bilingual advantage, with no single factor being decisive. "Increasing bilingualism" led to "increasing modification" of the brain, they said.
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 commented: "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 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.
"With 820,000 people in the UK living with dementia and this number expected to rise, it is vital to invest in research to understand more about how to prevent or delay the onset of this devastating condition." Original article from the Telegraph