Does Speaking Several Languages ​​protect Against Alzheimer’s?

Alzheimer’s is one of the most devastating and insidious neurodegenerative diseases, affecting memory, language and other essential cognitive functions. As the population ages, the number of cases continues to increase, which has led scientists to look for factors that can delay their onset or mitigate their effects. One of the most studied aspects in recent years is the possible role of bilingualism in protecting against cognitive decline.

Speaking more than one language requires constant mental effort: the brain must switch between languages, control interference, and manage multiple communication systems. This cognitive demand has led to the hypothesis that bilingualism could strengthen cognitive reserve, that is, the brain’s ability to compensate for damage caused by diseases such as Alzheimer’s.

Recent studies have analyzed the relationship between bilingualism and neurodegeneration, finding that people who speak two or more languages ​​could present slower deterioration in certain areas of the brain, compared to monolinguals. However, the question remains open: does it really protect against Alzheimer’s or simply delay its effects?

In this article, we will explore what science says about this relationship, What brain changes have been identified in bilingual people with Alzheimer’s and the extent to which learning and using multiple languages ​​can contribute to brain health in the long term.

What is Alzheimer’s and how does it affect the brain?

Alzheimer’s is a progressive neurodegenerative disease that is considered the most common cause of dementia in older adults. It is characterized by the gradual deterioration of memory, language, and other cognitive functions, eventually affecting a person’s ability to carry out daily activities.

At the brain and neuronal level, Alzheimer’s is associated with the abnormal accumulation of two proteins: beta-amyloid plaques and tau tangles. Beta-amyloid plaques are deposited between neurons, disrupting communication between them, while tau tangles form inside nerve cells, affecting their stability and causing their degeneration. Over time, these alterations lead to neuronal death and a reduction in brain volume.

One of the first areas affected is the hippocampus, a key structure in memory formation and learning. Its deterioration causes memory problems characteristic of the disease. As Alzheimer’s progresses, damage spreads to other regions of the brain responsible for logical thinking, decision making, and emotional regulation. This explains symptoms such as confusion, personality changes, and difficulty communicating.

In advanced stages, patients lose the ability to recognize their loved ones and require constant assistance. Although there is no cure, some strategies can help slow the progression of the disease. Among them, maintaining a cognitively active life has gained great interest in research, highlighting the possible role of bilingualism as a protective factor against brain deterioration.

The theory of cognitive reserve and bilingualism

The concept of cognitive reserve refers to the brain’s ability to resist deterioration caused by neurodegenerative diseases, injuries or aging. It is based on the idea that certain experiences throughout life can strengthen the structure and functioning of the brain, allowing it to compensate for damage and maintain better cognitive performance for longer.

Various factors contribute to this reserve, such as a high level of education, participation in intellectually stimulating activities, physical exercise, and social interaction. In this context, bilingualism has aroused great interest, since Learning and using two languages ​​requires constant mental effort.

Bilingual people must switch from one language to another depending on the context, and suppress the irrelevant language in each situation, which implies greater use of cognitive functions such as attention, executive control and working memory. This activity strengthens neural connections and could make the brain more resistant to deterioration.

Previous studies have suggested that bilingual people develop dementia symptoms later than monolinguals, despite presenting similar neurological signs in the brain. This would indicate that bilingualism does not prevent Alzheimer’s, but it could delay its onset or reduce its impact on daily life.

Since Alzheimer’s affects key regions for memory and language processing, such as the hippocampus and prefrontal cortex, it has been hypothesized that bilingualism may act as a protective factor. However, the scientific evidence needs to be examined more closely to better understand its impact on disease development.

The scientific evidence: Coulter’s study and its findings

To investigate whether bilingualism can protect against Alzheimer’s, researcher Kristina Coulter and her team analyzed neuroimaging data from two large databases: the Comprehensive Assessment of Neurodegeneration and Dementia Study (COMPASS-ND) and the Consortium for the Early Identification of Alzheimer’s Disease-Quebec (CIMA-Q). His study, published in the journal Bilingualism: Language and Cognition, examined brain differences between monolingual and bilingual people diagnosed with Alzheimer’s or at risk of developing dementia.

The researchers collected data from 531 participants and divided them into two groups: monolinguals (they spoke only one language) and bilinguals (they spoke two or more languages). Using MRI scans, they compared the gray matter volume and brain structure of both groups. The results showed that monolingual Alzheimer’s patients had a significant reduction in the volume of the hippocampus, one of the areas most affected by the disease and key to memory. On the other hand, bilingual Alzheimer’s patients did not present this deterioration to the same magnitude, suggesting that speaking several languages ​​could contribute to brain reserve and help maintain brain structure for longer.

However, the study found no significant differences in the thickness of the cerebral cortex in language areas, indicating that bilingualism does not specifically protect these regions. The authors concluded that bilingualism appears to offer a form of brain maintenance in Alzheimer’s, although it does not necessarily act as a shield against the disease.

These findings support the idea that speaking more than one language could help delay the effects of Alzheimer’s, although more research is still needed to fully understand this phenomenon and its clinical implications.

Is it definitive that bilingualism protects against Alzheimer’s?

Studies like the one described suggest that bilingualism could play an important role in protecting the brain against the impact of Alzheimer’s, by helping to preserve key structures such as the hippocampus. However, it has not been shown to prevent the disease or specifically protect language areas. In other words, bilingual people can also develop Alzheimer’s, but they might experience slower cognitive decline compared to those who only speak one language.

These findings support cognitive reserve theory, which maintains that the brain can develop strategies to compensate for neuronal damage. Learning and using several languages ​​requires constant management of attention and working memory, strengthening neural networks that can delay the appearance of clinical symptoms. However, Alzheimer’s is a complex disease, influenced by multiple factors such as genetics, age, lifestyle and general health.

It is important to highlight that, Although bilingualism appears to have cognitive benefits, it should not be considered an exclusive strategy to prevent dementia. Keeping the brain active through education, physical activity, social interaction, and continuous learning also contributes to long-term brain health.

As a small conclusion, speaking more than one language can be a factor that helps reduce the impact of Alzheimer’s, but it is not a guarantee against the disease. More research is needed to better understand its role and how it combines with other protective factors of the brain.