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Bilingualism may delay Alzheimer’s

Nov. 12, 2010
Courtesy of Baycrest
and World Science staff

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.

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Speaking two or more languages may help delay Alzheimer’s disease symptoms by as much as five years, new research has found. A 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 the monolingual 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 for Alzheimer’s disease, there are currently no drug treatments that show any effects on delaying Alzheimer’s symptoms, let alone delaying the onset of these symptoms by up to five years,” said Morris Freedman, director Ross Memory Clinic at Baycrest.