Bilinguals beat dementia
South Africans' almost universal bilingualism could save them from dementia.
A study by Canadian scientists has found that bilingual individuals are able to save brainpower and complete tasks without using the brain's frontal regions, which are vulnerable to ageing.
"After years of daily practice managing interference between two languages, bilinguals become experts at selecting relevant information and ignoring information that can distract them from a task," said Ana Inés Ansaldo, a professor at the University of Montreal.
Monolingual brains aren't so lucky. People who can speak and understand only one language require the use of multiple brain regions to complete tasks, making them less able to stave off the signs of dementia.
"Bilinguals juggle two languages at a time, which requires more effort from the brain," said Emanuel Bylund, a lecturer in linguistics at Stellenbosch University.
"You have to constantly suppress one language so that it doesn't come out when you're using the other.
"The onset of dementia is usually later in bilingual individuals, but a number of other experiences might postpone dementia, such as doing crosswords, having a rich social life and exercising.
"However, there isn't a lot of research on this topic in the South African context and it is not yet known which of these experiences is the most efficient."
Said Ansaldo: "Having more centralised and specialised functional connections saves resources compared to the multiple and more diverse brain areas allocated by monolinguals to accomplish the same task."
His research follows findings last year that toddlers who switch between languages develop better creative problem-solving skills than children who can speak only one language. This is because using two languages makes the brain more flexible.
According to the 2011 census, there are about 2.2million people in South Africa with some form of dementia.
Alzheimer's SA said there were an estimated 44.4 million people with dementia worldwide in 2013, with this number expected to increase to 75.6 million in 2030 and 135.5 million in 2050.
The SA Medical Journal said little was known about the prevalence of dementia or its effect on older adults living in low- and middle-income countries such as South Africa.