Scientists Say They Have Physical Proof Bilingualism Delays Onset of Alzheimer’s
October 16, 2011
When an editor at a major celebrity magazine proposed a profile of an educator teaching two-year-olds to speak second languages a few years ago, the editor in chief scoffed: “For what, so they can order their food in French?’ An embarrassed silence filled the air.
Now, a Canadian study has given a stunning retort:
People who speak more than one language suffer twice as much brain damage as those who speak only one language before they exhibit symptoms of Alzheimer’s disease. The study provides the first physical evidence that bilingualism delays the onset of the disease. Prior studies have suggested that bilingualism retards by four to five years the onset of the cognitive issues of Alzheimer’s.
“No drug can come close, and now we have the evidence to prove this at the neuroanatomical level,” said Dr. Tom Schweizer, a neuroscientist who headed the research at St. Michael’s
Schweizer’s team studied CT scans of patients who had been diagnosed with probable Alzheimer’s disease and who had similar levels of education and cognitive skills, such as attention, memory, planning and organization. Half were bilingual and able to speak at least two languages fluently; the other half spoke only one language.
Despite performing equivalently on all measures of cognitive performance, bilingual patients showed twice as much atrophy in areas of the brain known to be affected by Alzheimer’s.
Schweizer theorized that said speaking two languages exercises the brain and helps develop additional neural networks, adding to what neuroscientists call cognitive reserve. That is, despite damage from the disease, the brain is able to recruit help from enhanced neural networks in undamaged regions of the brain and better compensate for damage the disease causes.
Here’s a video of an interview with Schweizer:
The findings have been published on-line in the journal Cortex.