Authors Tyler Phillips (Research Psychologist & Research and Content Consultant) and Dr Etienne van der Walt (Neurologist and CEO & founder of Neurozone®)
Bilingualism and Brain Resilience
Research has shown that bilingual people tend to develop dementia 4 to 5 years later than monolingual people. This suggests that knowing and using more than one language may help the brain stay resilient against age-related decline. A recent study sought to understand how this may happen by examining brain scans of bilingual and monolingual older adults.
The Study Design
The study involved 364 older Canadians, with an average age of 68–74. Participants were categorized into four groups based on their cognitive health:
- Cognitively unimpaired (control group)
- Subjective cognitive decline (self-reported memory issues but normal objective test scores)
- Mild cognitive impairment (measurable cognitive decline, but not yet Alzheimer’s)
- Alzheimer’s disease diagnosis
Each group was further divided into monolingual and bilingual participants. To ensure a fair comparison between groups, researchers matched individuals by age, sex, education level, and scores on memory and cognitive function tests. Brain scans (MRIs) were then analyzed, focusing on regions involved in language control and Alzheimer’s progression.
The Key Finding: It’s All in the Hippocampus
The results revealed that bilingual participants had significantly larger hippocampal volumes than monolingual individuals in the same cognitive category. The hippocampus, a critical structure for learning and memory, is one of the first regions affected by Alzheimer’s.
However, bilinguals did not have larger hippocampi than the cognitively healthy control group. Instead, monolinguals with or at risk for Alzheimer’s showed more shrinkage in this brain region. This suggests that bilingualism doesn’t necessarily enhance brain size—it helps preserve the hippocampus, keeping it stronger for longer.
Interestingly, researchers did not observe significant differences in the overall size of language-related brain areas. This indicates that the protective effect of bilingualism may not come directly from language processing itself but from the broader cognitive demands associated with managing multiple languages.
Mental Stimulation Is Key
Speaking more than one language may help keep the brain engaged in several ways, such as through:
- Memory activation – Switching between languages requires recalling different words and grammatical structures, keeping memory sharp.
- Continuous learning – Bilinguals encounter new vocabulary in more than one language, which might mean greater semantic learning for them than monolinguals.
- Perspective shifts – Since language shapes how we perceive the world, bilinguals may naturally engage in more varied ways of thinking than monolinguals.
This ongoing mental stimulation may be the key to protecting the hippocampus. Other cognitive activities have also been shown to slow Alzheimer’s progression, reinforcing the idea that an active brain is a resilient brain.
The Takeaway: Keep Learning, Keep Engaging Memory
If you’re monolingual, this doesn’t mean you need to rush to learn a second language to protect against dementia. While learning a new language can be beneficial, the real takeaway is that continuous learning and mental engagement are crucial for brain health.
Neurozone® offers several ways to keep your brain active, learn, and shift perspectives, such as the High-Performance Course and Microlearning Journey. We have shown that the microlearning journey significantly boosts psychological resilience, so it may also help maintain brain health on a structural level.
Whether through learning a new language, studying how your brain-body system works, or exploring new topics that intrigue you, a key to aging resiliently is to keep your mind engaged. The more you challenge your brain, the better prepared it may be to stay strong for years to come.