Alzheimer's symptoms by as long as five years, Canadian scientists said Tuesday.
The Baycrest's Rotman Research Institute researchers examined clinical records of 211 patients diagnosed with Alzheimer's disease and found that those who spoke two or more languages consistently over many years experienced a delay in the onset of their symptoms by as long as five years.
The study was published in the current issue of 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," said lead investigator Fergus Craik.
The subjects' brains still showed deterioration from Alzheimer's regardless of language skills, however bilingualism appeared to have delayed symptoms such as memory loss, confusion, and difficulties with problem-solving and planning.
There are currently no drug treatments that can delay the symptoms of Alzheimer's, the researchers noted.
The study replicated findings from a 2007 study led by Ellen Bialystok of York University that found bilingual dementia patients experienced a delayed onset of their symptoms compared to monolingual patients.

The #1 most emailed story from the New York Times
By CLAUDIA DREIFUS - Published: May 30, 2011
A cognitive neuroscientist, Ellen Bialystok has spent almost 40 years learning about how bilingualism sharpens the mind. Her good news: Among other benefits, the regular use of two languages appears to delay the onset of Alzheimer’s disease symptoms. Dr. Bialystok, 62, a distinguished research professor of psychology at York University in Toronto, was awarded a $100,000 Killam Prize last year for her contributions to social science. We spoke for two hours in a Washington hotel room in February and again, more recently, by telephone. An edited version of the two conversations follows.

Read more here.