Can bilingualism protect the brain even with early stages of dementia?

A study by York University psychology researchers provides new evidence that bilingualism can delay symptoms of dementia. Alzheimer's disease is the most common form of dementia, making up 60 to 70 per cent of dementia cases. Of all activities with neuroplastic benefits, language use is the most sustained, consuming the largest proportion of time within a day. It also activates regions across the entire brain. Ellen Bialystok, Distinguished Research Professor in York's Department of Psychology, Faculty of Health, and her team tested the theory that bilingualism can increase cognitive reserve and thus delay the age of onset of Alzheimer's disease symptoms in elderly patients.

Their study is believed to be the first to investigate conversion times from mild cognitive impairment to Alzheimer's disease in monolingual and bilingual patients. Although bilingualism delays the onset of symptoms, Bialystok says, once diagnosed, the decline to full-blown Alzheimer's disease is much faster in bilingual people than in monolingual people because the disease is actually more severe.

"Imagine sandbags holding back the floodgates of a river. At some point the river is going to win," says Bialystok. "The cognitive reserve is holding back the flood and at the point that they were when they were diagnosed with mild cognitive impairment they already had substantial pathology but there was no evidence of it because they were able to function because of the cognitive reserve. When they can no longer do this, the floodgates get completely washed out, so they crash faster."

In the five-year study, researchers followed 158 patients who had been diagnosed with mild cognitive impairment. For the study, they classified bilingual people as having high cognitive reserve and monolingual people as having low cognitive reserve.

Patients were matched on age, education, and cognitive level at the time of diagnosis of mild cognitive impairment. The researchers followed their six-month interval appointments at a hospital memory clinic to see the point at which diagnoses changed from mild cognitive impairment to Alzheimer's disease. The conversion time for bilinguals, 1.8 years after initial diagnosis, was significantly faster than it was for monolinguals, who took 2.6 years to convert to Alzheimer's disease. This difference suggests that bilingual patients had more neuropathology at the time they were diagnosed with mild cognitive impairment than the monolinguals, even though they presented with the same level of cognitive function.

These results contribute to the growing body of evidence showing that bilinguals are more resilient in dealing with neurodegeneration than monolinguals. They operate at a higher level of functioning because of the cognitive reserve, which means that many of these individuals will be independent longer, Bialystok says. This study adds new evidence by showing that the decline is more rapid once a clinical threshold has been crossed, presumably because there is more disease already in the brain.

"Given that there is no effective treatment for Alzheimer's or dementia, the very best you can hope for is keeping these people functioning so that they live independently so that they don't lose connection with family and friends. That's huge."

Berkes M, Bialystok E, Craik F, Troyer A, Freedman M.
Conversion of Mild Cognitive Impairment to Alzheimer Disease in Monolingual and Bilingual Patients.
Alzheimer Disease & Associated Disorders, 2020. doi: 10.1097/WAD.0000000000000373.

Most Popular Now

Favipiravir flu drug 'clearly effective' in treati…

According to the multiple news articles the drug favipiravir (sold under the brand name Avigan), developed by Fujifilm Toyama Chemical, had produced encouraging outcomes ...

Understanding how COVID-19 affects children vital …

Though COVID-19 so far appears to be largely sparing children, researchers are cautioning that it is critical to understand how the virus affects kids to model the pandem...

Roche initiates Phase III clinical trial of Actemr…

Roche (SIX: RO, ROG; OTCQX: RHHBY) is working with the Food & Drug Administration (FDA) to initiate a randomised, double-blind, placebo-controlled Phase III clinical tria...

Free EDC software for non-profit COVID-19 related …

Italy-based EDC provider, Nubilaria srl, offers its ACTide EDC pro-bono for European non-profit COVID-19 Coronavirus related studies. The platform is made available for t...

Novartis commits to donate up to 130 million doses…

Novartis announced its commitment to donate up to 130 million doses of generic hydroxychloroquine to support the global COVID-19 pandemic response. Hydroxychloroquine and...

AstraZeneca to donate 9 million face masks to supp…

AstraZeneca is donating nine million face masks to support healthcare workers around the world as they respond to the COVID-19 (novel coronavirus) global pandemic. AstraZ...

Vivli to launch a portal for sharing data from COV…

In a visible sign of data sharing leadership, Vivli, the Center for Clinical Research Data has committed to serving the open science community through the launch of a COV...

CAR macrophages go beyond T cells to fight solid t…

Chimeric antigen receptor (CAR) T cell therapy has been a game-changer for blood cancers but has faced challenges in targeting solid tumors. Now researchers from the Pere...

COVID-19: The immune system can fight back

Melbourne researchers have mapped immune responses from one of Australia's first novel coronavirus (COVID-19) patients, showing the body's ability to fight the virus and ...

Singapore modelling study estimates impact of phys…

A new modelling study conducted in a simulated Singapore setting has estimated that a combined approach of physical distancing [2] interventions, comprising quarantine (f...

New kind of CRISPR technology to target RNA, inclu…

CRISPR-based genetic screens have helped scientists identify genes that are key players in sickle-cell anemia, cancer immunotherapy, lung cancer metastasis, and many othe...

Roche response to COVID-19 pandemic

Roche Group (SIX: RO, ROG; OTCQX: RHHBY), provided an update on the various actions the company is taking to address the COVID-19 pandemic. On March 19, 2020, Roche co...