Brain with language symbols

Decoding Bilingualism: Does Speaking Two Languages Really Protect Your Brain?

Avery Sinclair in Health & Wellness November 2025 • 4 min read.

"Exploring the Myths and Realities of Bilingualism and Cognitive Decline"

In an increasingly globalized world, bilingualism is becoming more common. But beyond the practical advantages, does speaking more than one language offer cognitive benefits? The idea that bilingualism might protect against cognitive decline has gained traction, sparking considerable interest and research.

Dementia is a growing global health concern, and any potential strategies for prevention or delay are valuable. Education and lifestyle factors have been identified as key components in maintaining cognitive health. The question is, does bilingualism truly stand out as a protective factor, or are other elements at play?

This article explores the findings of a recent study, 'The Relationship of Bilingualism to Cognitive Decline: The Australian Longitudinal Study of Ageing,' to demystify the connection between bilingualism and brain health. We'll break down the study's methods, results, and conclusions to provide a clear understanding of what the science really says.

The Australian Longitudinal Study of Ageing: Unpacking the Research

The Australian Longitudinal Study of Ageing (ALSA) tracked 2087 participants over the age of 65 for more than 20 years. The study aimed to clarify the relationship between bilingualism and cognitive decline, examining whether any protective effects could be attributed to improved executive function—the brain's ability to manage complex cognitive tasks.

Researchers compared various factors between bilingual and non-bilingual participants, including demographics, health, and social characteristics. They used linear mixed models to analyze how bilingualism affected scores on the Mini-Mental State Examination (MMSE), a common test for cognitive function, over time. The study also looked at the impact of bilingualism on baseline MMSE scores, controlling for potential confounding variables such as education and pre-existing health conditions.

The study revealed several key findings:

Bilingual participants initially had lower baseline MMSE scores compared to their monolingual counterparts.
This difference was largely explained by variations in education levels and scores on the National Adult Reading Test (NART).
There was no significant difference in the rate of MMSE score decline over time between bilingual and non-bilingual participants.
Bilingualism did not show a protective effect against cognitive decline in this cohort.

Ultimately, the study concluded that education, rather than bilingualism alone, was a stronger predictor of MMSE scores. The potential cognitive benefits of bilingualism appear to be complex and closely tied to factors such as educational attainment and specific patterns of language use.

The Bigger Picture: Rethinking Bilingualism and Brain Health

While this particular study didn't find a direct protective effect of bilingualism on cognitive decline, it's essential to remember that research in this area is ongoing and complex. The way individuals acquire and use multiple languages, their educational background, and cultural context all play a role. It seems that the cognitive benefits of bilingualism are not simply about knowing two languages, but rather about the depth and nature of that knowledge and its integration into daily life.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1002/gps.4778, Alternate LINK

Title: The Relationship Of Bilingualism To Cognitive Decline: The Australian Longitudinal Study Of Ageing

Subject: Psychiatry and Mental health

Journal: International Journal of Geriatric Psychiatry

Publisher: Wiley

Authors: Naaheed Mukadam, Fatima Jichi, David Green, Gill Livingston

Published: 2017-08-31

Everything You Need To Know

What methodology did the Australian Longitudinal Study of Ageing employ to investigate the relationship between bilingualism and cognitive decline?

The Australian Longitudinal Study of Ageing tracked 2087 participants over the age of 65 for more than 20 years. The study compared various factors between bilingual and non-bilingual participants, including demographics, health, and social characteristics. They analyzed how bilingualism affected scores on the Mini-Mental State Examination (MMSE) over time. It also looked at the impact of bilingualism on baseline MMSE scores, controlling for potential confounding variables such as education and pre-existing health conditions. The study used linear mixed models to analyze the data.

What were the primary findings of the Australian Longitudinal Study of Ageing regarding the impact of bilingualism on cognitive decline, as measured by the Mini-Mental State Examination (MMSE)?

The study's findings indicated that bilingual participants initially had lower baseline Mini-Mental State Examination (MMSE) scores compared to monolingual participants. Crucially, this difference was largely explained by variations in education levels and scores on the National Adult Reading Test (NART). The study also revealed that there was no significant difference in the rate of MMSE score decline over time between bilingual and non-bilingual participants. Therefore, bilingualism did not exhibit a protective effect against cognitive decline within the Australian Longitudinal Study of Ageing cohort.

If the Australian Longitudinal Study of Ageing didn't find a protective effect from bilingualism, what other factors were highlighted as potentially more influential in cognitive health?

While the Australian Longitudinal Study of Ageing did not find a direct protective effect, it's vital to recognize the complexity of research in this area. Factors such as how individuals acquire and use languages, educational background, and cultural context significantly influence the cognitive implications of bilingualism. The benefits aren't solely about knowing two languages, but the depth and how it integrates into daily life. The study emphasized that education was a stronger predictor of cognitive performance, measured by the Mini-Mental State Examination (MMSE) scores, than bilingualism alone.

What is the Mini-Mental State Examination (MMSE) and how was it utilized within the context of the Australian Longitudinal Study of Ageing to assess cognitive function?

The Mini-Mental State Examination (MMSE) is a widely used test to assess cognitive function. The Australian Longitudinal Study of Ageing used the MMSE to track cognitive performance of participants over time, comparing changes in scores between bilingual and monolingual individuals. While the study found that bilingual participants had lower baseline MMSE scores, it attributed these differences to factors like education rather than bilingualism itself, and did not find any difference in the rate of decline.

What is the National Adult Reading Test (NART) and how did the Australian Longitudinal Study of Ageing utilize it to control for potential confounding variables in their analysis of bilingualism and cognitive decline?

The National Adult Reading Test (NART) is a test used to estimate premorbid intellectual ability. The Australian Longitudinal Study of Ageing used NART scores to account for differences in cognitive reserve or general cognitive ability between participants. The study found that differences in NART scores, along with educational levels, helped explain the lower baseline Mini-Mental State Examination (MMSE) scores observed in bilingual individuals, suggesting that these factors may have influenced the initial cognitive assessments.