Speaking two or more languages may help delay Alzheimer’s disease symptoms by as much as five years, research has found.
A new study examined medical records of 211 patients diagnosed with probable Alzheimer’s, a devastating memory-erasing disorder estimated to affect one in eight people 65 years of age or older in the United States alone.
The researchers found that symptoms started as much as five years later for people who had spoken two or more languages consistently over many years. The study led by scientists at Baycrest, an academic center affiliated with the University of Toronto, is published in the Nov. 9 issue of the journal 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 Fergus Craik of Baycrest, lead investigator of the study and co-editor of The Oxford Handbook of Memory.
The brains of people who speak two languages still show deterioration from Alzheimer’s pathology, the researchers noted. But their extra language abilities seem to equip them with compensatory skills to hold back the tell-tale symptoms, such as memory loss, confusion, and difficulties with problem-solving and planning.
The patients in the study had been diagnosed between 2007 to 2009 at Baycrest’s Sam and Ida Ross Memory Clinic.
The researchers found that bilingual patients had been diagnosed with Alzheimer’s 4.3 years later and had reported the onset of symptoms five years later than one-language patients. The groups were equivalent on measures of cognitive and occupational level, there was no apparent effect of immigration status, and there were no gender differences, the investigators noted.
The paper replicates findings from a 2007 study led by Ellen Bialystok of York University in Canada, a collaborator in the new study also, and published in the journal Neuropsychologia. That analysis examined the records of 184 patients diagnosed with probable Alzheimer’s and other forms of dementia – and found that bilingual patients delayed the onset of their symptoms by four years compared to monolingual patients.
The current study adds to mounting evidence that lifestyle factors – such as regular 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, investigators said.
“Although a great deal of research is being focused on the development of new and more effective medications… there are currently no drug treatments that show any effects on delaying Alzheimer’s symptoms,” said Morris Freedman, who directs the memory clinic at Baycrest.