Learning a Foreign Language Can Delay the Onset of Dementia

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Dementia, a debilitating form of cognitive impairment, can be preventable. According to Professor Jubin Abutalebi of the University Vita Salute San Raffaele, Italy, and the Arctic University of Tromsoe, Norway, the easiest way to prevent cognitive decline after the age of 60 is to learn and practice foreign languages – the more languages, the better, suggests Professor Abutalebi in his presentation 'Preventing dementia through bilingualism' at the XXIV Yasin (April) International Academic Conference.

According to Abutalebi, the fewer languages a person uses, the more likely they are to develop a neurodegenerative disease. Currently, there are over 1.5 million people with dementia in Russia, and worldwide the number exceeds 44 million. Professor Abutalebi is confident that bilingualism – the ability to communicate effectively in two languages – can significantly delay the onset of dementia.

Jubin Abutalebi

Migration provides an interesting example in this context, as individuals who move to another country must learn the local language while still using their native language, making bilingualism both an opportunity and a necessity.

Several lifestyle factors, such as regular physical exercise and social engagement, have been reported to contribute to cognitive resilience in seniors. However, it is not widely known that speaking more than one language could potentially prevent neurodegenerative diseases. From an economic perspective, this could translate into significant cost savings for public healthcare and individuals in terms of treatment expenses, Abutalebi noted.

He briefly described the structure of the human brain with reference to psychometrics, a scientific discipline that investigates how an individual's behaviour is related to processes in their brain. The human brain consists of three parts: sensory, cortical, and motor. The sensory part of the brain receives information from the external world, the cortical part processes this information, and the motor part generates impulses for action. The anterior cingulate cortex (ACC), which is responsible for cognitive functions such as decision-making, error monitoring, and impulse control plays a key role in psychometrics. In 2011, Abutalebi conducted a neuroimaging study to investigate the correlation between grey matter volume and behavioural reactions and found that individuals proficient in two languages had a larger volume of grey matter and displayed a fractionally faster activation of the cortex compared to monolingual individuals.

Aging is a natural process often leading to cognitive impairment. The human brain is usually well-preserved until the age of 60, but after this age, it begins to experience partial atrophy, Abutalebi explained.  According to the cognitive reserve hypothesis, there are factors contributing to cognitive resilience in aging seniors, such as educational attainment, physical exercise, intellectual and social engagement. Abutalebi's study revealed that individuals with a higher cognitive reserve exhibited better brain plasticity, resulting in a later onset but faster progression of the disease. Taking medication at an early stage of dementia can slow down its progression for several months. Abutalebi’s most recent research confirms his hypothesis that bilingualism is a powerful and promising contributor to cognitive resilience and prevention of dementia.

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Abutalebi explains that people who speak more than one language and develop dementia tend to do so four to five years later than monolingual individuals. The reason may be that as individuals age, their brain begins to experience a decline in function and compensates by utilising the frontal regions, where there is an increase in white matter density. However, speaking more than one language has been shown to help the brain retain white matter density and even increase grey matter density.

This has been demonstrated in studies conducted in Hong Kong, Beijing, and Toronto. In 2017, a study conducted in Hong Kong focused on the left temporal lobe, which is typically one of the first areas to experience atrophy in individuals who begin forgetting names of people and objects. According to Abutalebi, while the left hemisphere is more active in memory processing for young people, older individuals need to engage the other hemisphere to compensate for memory loss. The study found that the more names of people and objects that people were able to remember in the second language, the less their left hemisphere had changed. However, discontinuing the use of a second language can accelerate the progression of dementia.

Abutalebi expanded his research by including a group of individuals who could communicate using sign language as well as spoken language, and his hypothesis was confirmed once again. Speaking two languages that significantly differ from each other has been shown to preserve grey matter density and to delay the onset of neurodegenerative diseases. However, the results may differ for individuals who speak, e.g., two dialects of Chinese since these languages are similar.

Author: Louisa Amelina, Research Assistant, HSE Laboratory for Economic Journalism