Brain ageing does not proceed at the same rate for everyone. Some people retain lucidity and memory well into old age, whilst others show signs of decline as early as age 50. The difference, according to a new study published in Nature Ageing, may also depend on something surprisingly everyday: how many languages we habitually speak.
The research, conducted amongst more than 86,000 individuals in 27 European countries, is the largest ever conducted on the topic and introduces for the first time a quantitative method for measuring the impact of multilingualism on biological ageing. The results indicate that those who regularly use more than one language are 54 per cent less likely to experience accelerated ageing than those who speak only one.
The international team of researchers developed the“biobehavioural age gaps” indicators (BAGs), which calculate the difference between registry age and biological age by considering the interaction between protective factors-such as physical function, preserved cognitive ability, and educational level-and risk factors, including cardiovascular disease, hypertension, and sensory deficits.
The effect grows with the number of languages
Epidemiological data reveal a progressive relationship. Those who speak only their native language have a 2.11-fold increased risk of accelerated ageing. In contrast, speaking at least one foreign language in addition to one’s own reduces this risk. The effect intensifies with the number of languages.
Particularly significant is that the protective effect remains constant across all age groups analyzed-from 51 to 90 years-and tends to increase with advancing years for those who speak two or more foreign languages.
The importance of real use
“What we found is that living in multilingual societies is delaying the cognitive and functional decline that typically comes with ageing,” Lucía Amoruso, a psychologist at the Basque Centre on Cognition in Spain and co-author of the study, explained to National Geographic.
The researcher also pointed out that the protective effect is about “real language use in everyday life” in “real contexts,” rather than just school knowledge. It is the continuous exercise the brain undertakes in managing multiple language systems-selecting the appropriate words, inhibiting those of the other language, switching from one grammar to another-that strengthens neural networks and builds what neuroscientists call “cognitive reserve.”
Scientific rigour and controls
Researchers have verified that multilingualism protects our brains regardless of our macro-environmental context.
The practical implications are encouraging. As
The benefits of multilingualism extend beyond protecting against cognitive ageing. People who are bilingual or multilingual show, on average, greater flexibility in executive functions, such as multitasking and decision making, as well as more developed creativity, better ability to concentrate, and greater resilience to stress.
Then there is an aspect that is often underestimated: language as social glue. As we age, social networks tend to shrink, increasing the risk of isolation, a factor in turn associated with cognitive and emotional decline. Speaking multiple languages makes it easier to connect with different communities and cultures, providing opportunities for interaction that help keep social life active.
A public health perspective
Whether it is picking up a language studied in youth, conversing with neighbours from other cultures, or simply living in linguistically diverse environments, the opportunities to keep one’s language repertoire active are many. And, unlike other prevention strategies, this one has the advantage of enriching social and cultural life as well as protecting cognitive health.
As Amoruso notes, what matters is immersion in authentic contexts rather than grammatical perfection. An approach that makes multilingualism one of the most democratic and sustainable tools for promoting healthy aging in contemporary societies.
