One such area is in brain aging, where bilingualism or multilingualism has shown to confer some protection on our cognition. Cognition is what we call our process of learning, experiencing, and thinking (Bayne et al., 2019) and is an area language researchers explore to gauge the effects of languages on our thoughts, thinking, and memories. As with many things, cognition is subject to the less pleasant aspects of aging.

Yet, cognitive reserve, a feature of cognition, is one that may be bolstered by one’s use of languages. Cognitive reserve can be described as the buffer between an intangible thinking and a physical brain that can sustain some cognitive function, despite a crumbling of physical mass. Knowing more than one language, as is in the case of bilingualism, can support cognitive reserve into old age and improve performance compared to those who speak one language (Bialystok, 2021). Bilingualism in earlier life stages may even create a cognitive protective effect that endures into old age (Ballarini et al., 2023). This is concluded from results on tasks or activities and/or through brain structure itself.

How do we measure cognition?

Cognitive tests and tools are used to measure different mental activities, like memory

How do we SEE the brain?

Brain activity and structures can be measured through brain scans, like those of functional Magnetic Resonance Imaging, or fMRI

An area of the brain that is of interest for neurological and language researchers alike is the hippocampus. Known for its role in memory, the hippocampus may also receive protection from bilingualism since hippocampal volume may increase with bilingualism (Voits et al., 2022). Though this is delightful news and there is much showing us the vigour of multiple language use, there are still inconsistencies in the research where some studies show little evidence for multi-language-based neuroprotection (Weyman et al., 2020; Gard et al., 2025). In the Gard et al. (2025) study, for example, older adult monolinguals did better than their bilingual counterparts on language tasks, but not on tasks that measured executive function.

What is executive function?

Executive function refers to how we manage our thinking, including its flexibility and control

All research comes with caveats, but ultimately evidence builds for bilingual and multilingual-based cognitive benefits. Some may see the smallness of samples as a limitation, which it very well is, but recent technologies have increased connectivity among research communities, allowing for larger and more diverse participant samples to coalesce. With a sample of over 85,000 participants across 27 countries (albeit European countries), a recent study provides strong support for multilingualism being a protective factor in aging and monolingualism increasing accelerated aging (Amoruso et al., 2025).

Like the foods we eat and the moves we make, language is another facet of our existence that inspires it.

© T. Y. Giri

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References

*Please note: References are not fully formatted.

Amoruso, L., Hernandez, H., Santamaria-Garcia, H., Moguilner, S., Legaz, A., Prado, P., Cuadros, J., Gonzalez, L., Gonzalez-Gomez, R., Migeot, J., Coronel-Oliveros, C., Cruzat, J., Carreiras, M., Medel, V., Maito, M. A., Duran-Aniotz, C., Tagliazucchi, E., Baez, S., García, A. M., & Ibanez, A. (2025). Multilingualism protects against accelerated aging in cross-sectional and longitudinal analyses of 27 European countries. Nature aging, 5(11), 2340–2354. https://doi.org/10.1038/s43587-025-01000-2

Ballarini, T., Kuhn, E., Röske, S., Altenstein, S., Bartels, C., Buchholz, F., Buerger, K., Dechent, P., Dobisch, L., Ewers, M., Fliessbach, K., Freiesleben, S. D., Frommann, I., Gabelin, T., Glanz, W., Görß, D., Haynes, J. D., Incesoy, E. I., Janowitz, D., … Wagner, M. (2023). Linking early-life bilingualism and cognitive advantage in older adulthood. Neurobiology of Aging, 124, 18–28. https://doi.org/10.1016/j.neurobiolaging.2022.12.005

Bayne, T., Brainard, D., Byrne, R. W., Chittka, L., Clayton, N., Heyes, C., Mather, J., Ölveczky, B., Shadlen, M., Suddendorf, T., & Webb, B. (2019). What is cognition? Current Biology, 29(13), R608–R615. https://doi.org/10.1016/j.cub.2019.05.044

Bialystok, E. (2021). Bilingualism: Pathway to Cognitive Reserve. Trends in Cognitive Sciences, 25(5), 355–364. https://doi.org/10.1016/j.tics.2021.02.003

Gard, S., Saad, J., Sheppard, C. L., & Taler, V. (2025). Monolinguals Outperform Bilinguals in Language but Not Executive Function in Aging and Cognitive Impairment. Neuropsychology, 39(8), 781–790. https://doi.org/10.1037/neu0001028

Voits, T., Robson, H., Rothman, J., & Pliatsikas, C. (2022). The effects of bilingualism on hippocampal volume in ageing bilinguals. Brain Structure and Function, 227(3), 979–994. https://doi.org/10.1007/s00429-021-02436-z

Weyman, K. M., Shake, M., & Redifer, J. L. (2020). Extensive Experience with Multiple Languages May Not Buffer Age-Related Declines in Executive Function. Experimental Aging Research, 46(4), 291–310. https://doi.org/10.1080/0361073X.2020.1753402