5 Minutes
As lifespans lengthen worldwide, researchers are racing to identify everyday habits that help preserve thinking skills into old age. New large-scale evidence suggests that knowing and using more than one language may do more than enrich travel and culture — it could also slow aspects of brain ageing.
Why multilingualism could act like daily brain training
When people switch between languages, their brains constantly choose the correct words while suppressing alternatives. That juggling doesn’t happen in a vacuum: it recruits attention, inhibition, memory and task-switching systems collectively known as executive control. Over decades, this recurrent cognitive work may strengthen neural networks and build what scientists call cognitive reserve — the brain’s ability to tolerate age-related changes and pathology without showing symptoms.
Put simply: selecting one language and holding others back is a mental workout. And like physical exercise, the benefits may accumulate with frequency and intensity.
What the new study found
Researchers analyzed data from more than 86,000 healthy adults aged 51 to 90 across 27 European countries. Using a machine-learning model, they estimated a person’s apparent age based on functional measures — memory performance, daily functioning, education, mobility and chronic health issues such as cardiovascular disease or hearing loss.
The difference between predicted age and chronological age produced a "biobehavioural age gap": negative values indicate someone appears younger than their years; positive values indicate they appear older. The team correlated that gap with each country’s level of multilingual exposure, measured as the share of people speaking zero, one, two, three or more additional languages.
Results were striking. Residents of highly multilingual countries — examples include Luxembourg, the Netherlands, Finland and Malta — were less likely to show accelerated ageing on the composite measure. Conversely, people in mostly monolingual countries such as the UK, Hungary and Romania tended to appear biologically older. Importantly, knowing one extra language made a meaningful difference, and speaking several languages showed a stronger, dose-dependent effect.
Who benefits most?
The protective pattern was clearest among adults in their late 70s and 80s. For this older cohort, bilingualism or multilingualism seemed to grant a noticeable resilience against age-related decline. The researchers adjusted for dozens of national variables — air quality, migration, gender inequality and political climate among them — and the multilingual advantage persisted, suggesting language experience itself contributes something unique.
How language use might change the brain
The study did not image brains directly, but other research offers plausible mechanisms. Managing multiple languages engages frontal networks responsible for inhibition and task switching, and it appears to affect the hippocampus, a structure vital for forming new memories. Some labs have reported larger hippocampal volumes in lifelong bilinguals, which is significant because hippocampal shrinkage is associated with memory loss and neurodegenerative diseases such as Alzheimer’s.
Repeated cognitive engagement from language switching could therefore bolster both the structural integrity and functional efficiency of these systems — contributing to cognitive reserve and slowing trajectories of decline.
Public-health implications and caveats
If multilingualism does protect the ageing brain, the finding has broad implications. Promoting language learning and maintaining use of more than one language across the lifespan could be an inexpensive, culturally adaptable public-health strategy to delay cognitive decline. Language-rich environments — schools, communities, workplaces — could function as informal cognitive interventions.
However, the research has limitations. Observational studies cannot prove causation. People who grow up multilingual often differ in education, social networks, and early-life experiences; while the study controlled for many country-level factors, unmeasured individual differences may still play a role. The machine-learning "predicted age" is a composite indicator, useful for population studies but not a diagnosis for individuals.
What researchers want to do next
Future work should combine longitudinal brain imaging with detailed measures of language use — not just how many languages someone knows, but how frequently and in which contexts they switch. Randomized interventions that teach a new language later in life could test whether acquiring a second language produces measurable cognitive or neural benefits. Such trials would help move the field from correlations to actionable recommendations.
Expert Insight
Dr. Maria Alvarez, a cognitive neuroscientist at the (fictional) Centre for Lifespan Brain Health, comments: "The idea that language experience shapes brain resilience is compelling because it ties a commonplace activity to measurable neural outcomes. Even modest gains in cognitive reserve across a population could translate into significant public-health benefits — fewer years with dementia, more years of independence. Still, we need controlled trials to understand how late-life learning compares with lifelong bilingualism."
In the meantime, the evidence supports a simple message: using more than one language appears to be a low-cost, high-value way to keep the mind active. Whether through formal classes, conversation groups or everyday use, language practice may be one of the most accessible tools we have to promote cognitive resilience as people age.
Source: sciencealert
Comments
bioNix
Interesting dataset, but is country-level multilingual exposure a valid proxy for individual practice? ML predicted-age is neat but not clinical, tbh. Need longitudinal MRI + randomized language training to prove causation
atomwave
wow didn't expect that... extra languages might slow brain ageing? super hopeful! but what about SES and education confounds, and actual usage frequency? still, sign me up for a class lol
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