Could Bilingualism Delay Alzheimer's Disease?

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

The 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 was published in a recent 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.

According to Dr. Craik, lead investigator and co-editor of The Oxford Handbook of Memory, "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."

The brains of people who speak two languages still show deterioration from Alzheimer's pathology; however, their special ability with two languages seems to equip them with compensatory skills to hold back the tell-tale symptoms of Alzheimer's, such as memory loss, confusion, and difficulties with problem-solving and planning.

"These results are especially important for multicultural societies like ours in Canada where bilingualism is common," said Dr. Bialystok. "We need to understand how bilingualism changes cognitive ability, especially when there are clinical implications as in this case."

The current study adds to mounting scientific evidence that lifestyle factors—such as regular cardiovascular exercise, a healthy diet, and speaking more than one language—can play a central role in how the brain copes with age-related cognitive decline and diseases such as Alzheimer's.

Source: Baycrest, a health sciences centre affiliated with the University of Toronto, is a world-class developer of innovations in ageing that enhance quality of life by optimizing physical and mental well-being. This study was supported by the Canadian Institutes of Health Research and the Alzheimer Society of Canada.

For More Information

To learn more about this study and to watch a video of Dr. Craik discussing the results, visit the Baycrest website.