Speaking two languages can be great for job opportunities and when you travel to another country. Now a new study adds significant support to the idea that if you are bilingual, you may have an edge on the development of Alzheimer’s symptoms by as many as five years.
Speaking two languages may protect the brain
An expert scientific team from Canada analyzed the clinical records of 211 patients who had been diagnosed with probable Alzheimer’s from the Sam and Ida Ross Memory Clinic at Baycrest over a two-year period. Of these, 102 patients were identified as bilingual and 109 as monolingual.
An evaluation of the patients revealed that those who spoke two languages had been diagnosed with Alzheimer’s 4.3 years later and reported the start of symptoms five years later than patients who spoke only one language. The authors published their results in the November 9 issue of Neurology.
In a previous study conducted by the same researchers, 184 patients with probable Alzheimer’s or other dementias were evaluated. The investigators found that speaking two languages throughout a person’s life appeared to delay the onset of dementia symptoms by four years when compared with people who spoke only one language.
More recently (2010), a study published in Alzheimer Disease and Associated Disorders reported that multilingualism seemed to offer protection against onset of Alzheimer’s disease but no significant benefit for those who spoke two languages.
According to Dr. Fergus Craik of Baycrest’s Rotman Research Institute and lead investigator of the latest study in Neurology, “We are not claiming that bilingualism in any way prevents Alzheimer’s or other dementias, but it may contribute to cognitive reserve in the brain which appears to delay the onset of Alzheimer’s symptoms for quite some time.”
Dr. Ellen Bialystok, co-investigator, and professor of psychology at York University, and associate scientist at the Rotman Research Institute, noted that “These results are especially important for multicultural societies like ours in Canada where bilingualism is common.” The team also included Dr. Morris Freedman, one of Canada’s leading experts in Alzheimer’s and other dementias.
The authors point out that the brains of individuals who speak two languages are still affected by deterioration associated with Alzheimer’s disease, but having the ability to speak two languages appears to protect the brain and provide compensatory skills to delay symptoms of dementia. Thus being bilingual, along with other lifestyle factors such as a healthy diet and regular exercise, may help fight Alzheimer’s disease.
Bialystok E et al. Neuropsychologia 2007 Jan 28; 45(2): 459-64
Chertkow H et al. Alzheimers Dis Assoc Disord 2010 Apr-Jun; 24(2): 118-25
Craik FI et al. Neurology 2010 Nov 9; 75(19): 1726-29