Speaking multiple languages slows down brain aging

Although medical advances are causing an increase in average life expectancy, the human brain begins to perform worse with age. At the neuronal level, aging manifests itself through anatomical changes in the grey and white matter in specific brain regions, while at the cognitive level, short- and long-term memory deteriorates, information-processing speed decreases, and control over linguistic, visuospatial, and executive skills declines. 

However, the speed of aging varies, depending upon a person’s cognitive reserve – the brain’s ability to maintain optimal performance while coping with age-related changes. This reserve is built up over the course of life, as the brain strengthens various neural networks in response to different stimuli. 

According to previous studies, the more complex these neural networks are, the greater a person’s cognitive reserve and thus capacity to cope with aging. While it is already well-known that cognitive reserve is influenced by various factors, such as physical activity, nutrition, level of education, career path, or socio-economic status, a new study led by the HSE University in Russia and Northumbria University in the UK has found for the first time that bilingualism is another strongly beneficial factor for cognitive reserve, and could help slow down and mitigate the course of age-related changes in the brain.

By conducting an experiment that measured the speed of cognitive functioning of 63 healthy older adults (aged 60 or above), the scientists found that the more fluent the participants were in a second language, the faster they were in solving the tasks they were presented with.

“Unlike other factors that shape cognitive reserve, bilingualism is unique in that it is constantly present in our lives. We can take up and give up physical exercise, go on one diet or another, or change jobs, but language remains with us all the time. We communicate, watch movies, and read books, and the language centers are constantly working in our mind,” explained study lead author Federico Gallo, a Junior Research Fellow at HSE. 

“We witnessed an interesting phenomenon in this experiment: with a high level of language proficiency, the correlation between successful conflict resolution and other components of cognitive reserve disappeared. This suggests that bilingualism’s benefits on cognitive reserve might be stronger than those of other known factors.”

According to Dr. Gallo and his colleagues, proficiency in two or more languages improves brain functioning not only in healthy people, but also in those with various neurodegenerative diseases. Moreover, bilingualism seems to improve not only the executive functioning of the brain, but also episodic, working, and semantic memory, together with overall intelligence.

“There are no really effective drugs available today to prevent or slow down brain ageing. It takes enormous financial resources to develop pharmaceutical treatments. Therefore, finding and researching alternative, non-drug ways to slow down cognitive ageing should become a priority in science. In the long term, we plan to study how the benefits of bilingualism on ageing may vary with different language pairs,” Dr. Gallo concluded.

The study is published in the journal Frontiers in Psychology.

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By Andrei Ionescu, Earth.com Staff Writer