Speaking multiple languages could slow down brain ageing, a study suggests

A study presented in Barcelona suggests that people who speak multiple languages have brains that appear younger than their actual age, with the effect being stronger in those who learnt foreign languages from an early age, according to The Guardian.

According to the research, those who speak two languages have brains roughly six years younger than those of single-language speakers. The difference rises to around seven years for those who speak three languages, and reaches approximately 13 years for those who speak four.

Why brain connections matter

The brain is made up of billions of interconnected nerve cells. As we age, these connections gradually deteriorate, which can lead to memory decline and slower thinking.

Previous research had already shown that, at a population level, European countries where knowledge of foreign languages is higher tend to show slower brain ageing. This time, researchers looked more closely at the effects of multilingualism at the individual level.

Who took part in the study

Researchers from Spain, Chile, Argentina, and Ireland examined individuals from the Basque Country, a region with a high degree of multilingualism. Participants spoke Spanish, Basque, French, and/or English.

To determine neurological age, the team used magnetoencephalography, a method of measuring brain activity, applied to 728 people of varying ages and levels of foreign language proficiency. The data were processed using artificial intelligence to calculate the normal level of brain connectivity expected at each age.

Comparing the results

The results were subsequently verified on a second, independent group of 144 people, divided equally according to the number of languages spoken — one, two, three, or four.

Dr. Lucia Amoruso, from the Basque Centre on Cognition, Brain and Language in San Sebastián, explained that the results depend not only on the number of languages spoken, but also on the level of proficiency and the age at which they were learnt: "In short, people who spoke more languages had brains that appeared younger than would be expected for their chronological age. The effect was not solely related to the number of languages spoken. A higher level of linguistic proficiency and learning a second language at an early age were also associated with a delay in brain ageing. This suggests that multilingual experience matters as a gradual process: it is not simply a matter of being bilingual or not, but about the depth and duration of linguistic experience."

Results that call for caution

The researchers took into account participants' age, sex, and level of education, but noted that they cannot rule out the influence of other factors on brain health, such as lifestyle or engagement in social activities.

Prof. Christina Dalla, a neuroscience specialist at the National and Kapodistrian University of Athens, commented: "This study suggests that learning a second, third, or even fourth language could help the brain stay younger for longer, and the earlier we start, the better. There are many reasons to learn a foreign language at any age — social, cultural, and for brain health — so we should support language learning both at school and throughout life, even if it is challenging."

Other possible explanations

Eef Hogervorst, professor of biological psychology at Loughborough University, urged caution in interpretation. Whilst the evidence points to a link between multilingualism and greater brain resilience, she noted that multilingual individuals may also tend to have healthier lifestyles or access to other activities that are beneficial for the brain, such as reading, continuous learning, or playing a musical instrument.