Speaking two languages could delay onset of Alzheimer's disease

Canadian science team that led 2007 study finds more evidence of 'protective effect'

A Canadian science team has found more dramatic evidence that speaking two languages can help delay the onset of Alzheimer's symptoms by as much as five years.

The latest study, led by Baycrest's Rotman Research Institute, examined the clinical records of more than 200 patients diagnosed with probable Alzheimer's disease and found that those who have spoken two or more languages consistently over many years experienced a delay in the onset of their symptoms by as much as five years. The study is published in the Nov. 9^th issue of Neurology.

The science team includes internationally-renowned cognitive researcher Dr. Fergus Craik of the Rotman Research Institute; Dr. Ellen Bialystok of York University, a leading expert in bilingualism research; and Dr. Morris Freedman, one of Canada's leading clinicians in the diagnosis and treatment of Alzheimer's and other dementias.

"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," said Dr. Craik, who is co-editor of The Oxford Handbook of Memory and lead investigator of the study.

The Neurology paper replicates findings from the team's widely-reported 2007 study led by Dr. Bialystok and published in Neuropsychologia.

There are currently no drug treatments that show comparable effects for delaying Alzheimer's symptoms, say the researchers.