Bilingualism delays onset of Alzheimer鈥檚 symptoms
Published: October 18, 2011
Researchers at St. Michael's Hospital and the 香港六合彩资料 have found that people who speak more than one language don鈥檛 exhibit symptoms of Alzheimer鈥檚 disease until they have twice as much brain damage as unilingual people. It's the first physical evidence that bilingualism delays the onset of the disease.
鈥淭his is unheard of 鈥 no medicine comes close to delaying the onset of symptoms and now we have the evidence to prove this at the neuroanatomical level,鈥 said Professor Tom Schweizer, a neuroscientist who headed the research.
Schweizer鈥檚 team studied CT scans of patients who had been diagnosed with probable Alzheimer鈥檚 disease and who had similar levels of education and cognitive skills, such as attention, memory, planning and organization. Half were fluently bilingual; the other half unilingual.
Despite the fact that both groups performed equivalently on all measures of cognitive performance, the scans of the bilingual patients showed twice as much atrophy in areas of the brain known to be affected by Alzheimer鈥檚.
The findings have been published on-line in the journal .
Schweizer, a professor of surgery who is cross-appointed to the Institute for Biomechanical and Biomedical Engineering, said that bilingual people are constantly using their brain and keeping it active, which may contribute to overall brain health. That鈥檚 why many physicians encourage older people to do crossword puzzles or Sudoku.
Schweizer notedd that because bilingual people constantly switch from one language to another or suppress one language to speak in the other, their brains may be better prepared to compensate through enhanced brain networks or pathways when Alzheimer鈥檚 sets in.
Previous observational studies have found that bilingualism delays the onset of Alzheimer鈥檚 symptoms by up to five years, but this is the first to find physical proof through CT scans.
Schweizer said the results are especially important in Canada, which is officially bilingual and has large numbers of immigrants for whom French and English are at least second languages. His study was conducted in Toronto, where the second language of many study participants was French, English or Chinese.
He noted that bilingualism does not prevent Alzheimer鈥檚. Once Alzheimer鈥檚 symptoms appear in bilingual people, it is not clear whether the disease progresses at an accelerated rate.
He said the next steps would be to repeat the study in a larger sample of patients followed over time using more sophisticated MRIs and noted it wasn鈥檛 clear from this study whether a second language had to be learned early in life to provide maximum benefit.
Topics
