Being bilingual delays dementia – study
Being able to speak another language delays the onset of dementia, researchers have found.
According to the findings of a new study, people who are capable of speaking a second language may delay the onset of three types of dementia. Also, people who speak two or more languages develop dementia four and a half years later than people who speak only one language.
The study funded by the Cognitive Science Research Initiative, Department of Science and Technology, Government of India, is published in the latest issue of Neurology, the medical journal of the American Academy of Neurology.
“Our study is the first to report an advantage of speaking two languages in people who are unable to read, suggesting that a person’s level of education is not a sufficient explanation for this difference,” study’s lead author Suvarna Alladi, from the Nizam’s Institute of Medical Sciences in Hyderabad, India said. “Speaking more than one language is thought to lead to better development of the areas of the brain that handle executive functions and attention tasks, which may help protect from the onset of dementia.”
For the purpose of the study, the researchers evaluated 648 Indians with an average age of 66 years. All participants were diagnosed with dementia. While 240 had Alzheimer’s disease, 189 had vascular dementia and 116 had frontotemporal dementia. Remaining participants suffered from Lewy bodies and mixed dementia.
Of all participants, 391 spoke two or more languages and 14 percent were illiterate.
The researchers found that people who spoke two languages had a later onset of Alzheimer’s disease, frontotemporal dementia and vascular dementia as compared to subjects who spoke only one language. This association was strong even in participants who were illiterate.
“These results offer strong evidence for the protective effect of bilingualism against dementia in a population very different from those studied so far in terms of its ethnicity, culture and patterns of language use,” Alladi said.
“Being bilingual is a particularly efficient and effective type of mental training. In a way, I have to selectively activate one language and deactivate the other language. This switching really requires attention,” study’s co-author Dr. Thomas H. Bak, explained.