Learning and using more than one language — i.e. being bilingual or multilingual — may help keep your brain younger and healthier, according to recent studies and decades of research. In 2025, a large study including over 80,000 adults found that those speaking multiple languages showed slower brain ageing compared to those who spoke only one. RNZ
What Happens in the Brain When You Speak Multiple Languages
- Enhanced brain connectivity & neuroplasticity: Using more than one language appears to strengthen communication between different parts of the brain — making neural connections more efficient and improving overall cognitive flexibility
- Better executive function (attention, task switching, memory): Research shows that bilingual people often perform better on tasks requiring attention control, switching between tasks, and managing multiple mental processes — skills linked to the brain’s “executive functions.”
- Stronger cognitive reserve — more resilience to ageing: Habitual use of multiple languages may build a “cognitive reserve,” helping the brain compensate for age-related changes and delaying cognitive decline.
Evidence: Slower Ageing & Delayed Cognitive Decline
- A 2025 international study of 80,000+ adults found that multilingual individuals had slower biological ageing compared to monolinguals.
- Multiple studies have found that bilingual or multilingual people may experience a delay in the onset of dementia or Alzheimer’s symptoms by several years — sometimes 4–5 years — compared to monolinguals.
- Neuroimaging studies suggest that lifelong bilingualism correlates with preservation of brain structure (e.g. grey-matter integrity) and better maintenance of neural functioning with age.
Why Speaking More Than One Language Helps: The “Mental Workout” Theory
The benefits likely arise because managing two or more languages forces your brain to constantly work — selecting the right language, inhibiting the other(s), switching contexts, recalling vocabulary, and juggling grammar rules. This mental juggling acts like a workout for various cognitive faculties: memory, attention, flexibility, and executive control.
Over time, this “workout” helps build stronger neural networks (neuroplasticity) and a more resilient brain — akin to how regular physical exercise strengthens muscles and endurance.
What This Means for You & Everyone — The Real-World Impact
- A potentially lower risk of dementia or delayed onset: If you speak more than one language — or learn one now — you may build cognitive resilience that helps you stay mentally sharp as you age.
- Mental agility throughout life: Bilingualism may enhance multitasking, problem solving, focus, and memory — useful skills for daily life, work, learning, and relationships.
- Easy to adopt & lifelong benefit: Unlike some interventions requiring special equipment or medicines, learning a new language is accessible — and benefits can accumulate over years or decades.
Things to Keep in Mind — It’s Not a Guaranteed “Fountain of Youth”
- Not all studies agree. Some prospective long-term studies did not find a reduced dementia incidence among bilinguals.
- Benefits may depend on how well and how often you use the languages; passive knowledge (e.g. school classes but no use) may not have the same effect.
- Other factors — education, social engagement, lifestyle, physical health — also matter a lot for brain ageing. Bilingualism helps, but it’s not a silver bullet.
Should You Start Learning a New Language Now? — I’d Say Yes
Given the weight of evidence, learning a second (or third) language seems like a smart investment in your long-term brain health. Even if the cognitive boost is modest, the potential to slow age-related decline, sharpen your mind, and add life-long flexibility makes it worthwhile.
