Dementia and Bilingualism: Can learning a second language thwart onset dementia?
According to a survey conducted by the language learning app, Memrise, 57 percent of users reported a “boost brain health” in bilingualism, or second language learning, but this study might be more than simply a motivation to promote use of its programme. Research suggests that bilingualism can delay the onset of dementia symptoms by strengthening cognitive reserve and enhancing brain resilience. This may be because learning a second language is difficult, challenging the brain and mind to work harder, creating new neural pathways when others begin to fade with age or damage.
A 2020 study on bilingualism protecting against dementia suggests that bilingualism may contribute to cognitive reserve (the resilience of the brain and mind to maintaining or regaining cognitive function despite ageing and damage of the brain, essentially acting as a buffer against cognitive decline) and neuroplasticity (the ability of the brain to form and reorganise the structure or function of the nervous system or synaptic connections upon the learning of or following an injury), and this may allow individuals to resist the cognitive decline of the disease progression associated with dementia. This study, through a meta-analysis of the data, discovered that the symptoms of dementia are halted by up to five years, on average, in those who fluently speak more than one language. However, the study did not substantially show that bilingualism deters dementia in its entirety; only that it helps to delay symptoms.
John Grundy, an assistant professor of psychology at Iowa State University, who published the above study with John Anderson (Centre for Addiction and Mental Health, Toronto, Canada) and Kornelia Hawrylewicz (Department of Psychology at York University, Toronto, Canada), said: “Bilinguals and monolinguals eventually show the same number of Alzheimer’s disease cases, but bilinguals tend to be able to stave off those symptoms for longer. That’s fascinating to me. Maybe the most surprising thing about the study is the consistency of the effect. It’s a very robust finding.”
Grundy also notes that, though bilingualism does not prevent or reverse dementia, it is a form of cognitive reserve that strengthens and reorganises the brain’s circuits which helps to fight off the initial symptoms of dementia until later in life. This study states that bilingual individuals rely on the posterior and subcortical regions of the brain for more efficient processing of information than monolingual individuals, of whom depend on the brain’s more demanding frontal circuits as they age, thus exacerbates the onset of dementia.
This research echoes the earlier 2007 study on bilingualism as a protection against the onset of symptomsof dementia which examines the effect of lifelong bilingualism on maintaining cognitive function and in delaying the onset of symptoms of dementia in old age. This study consisted of 184 patients diagnosed with dementia, 51% of whom were bilingual, and it determined that bilingual individuals showed symptoms of dementia four years later than monolingual individuals.
This research demonstrates that individuals who utilise their brains more through furthering their language with bilingualism tend to have lower rates of dementia and memory problems later in life regardless of outside factors such as gender, education levels, or occupation. This knowledge of languages can be of great benefit because it helps to keep the brain in good working order; bilingualism helps to open the mind in a very fundamental way, and the process exercises your brain, challenging you to concentrate, boosting key problem-solving skills.
A 2021 study on second language learning promoting neuroplasticity in ageing supports the suggestion that there are some indications of cognitive benefits associated with foreign language learning in later life, especially for executive functions. This study expresses an understanding on how maintaining cognitive abilities is essential in older adults, and it links bilingualism to higher cognitive reserve, better performance in executive control, and delay in dementia onset. It also suggests bilingualism supports changes in brain structure and function relative to monolinguals, and thus, learning seems a promising avenue for cognitive enhancement in older adults.
And it is not too late to reap the benefits of learning a second language. Caitlin Ware, a research engineer at Broca Hospital in Paris who studies bilingualism and brain health, suggests that the age at which we learn another language appears to be less important than how often we speak it. “The cognitive benefit is from having to inhibit your mother tongue, which your brain is forced to do if you’re trying to recall the right words in another language. So if the second language is used a lot, you’re getting that cognitive training.”
Grundy also echoes this: “The good thing is it’s never too late, and there are protective benefits of bilingualism and other factors, even at later ages in life. Anything that shocks your system, not just bilingualism, but anything that is a change in your routine is a good thing. Start writing with your left hand, take a different path home, anything that challenges your brain in a way that allows you to become more efficient over time leads to multiple networks and pathways to get to the same outcomes.”
Overall, the benefits of bilingualism, or second language learning, on dementia may include:
• Brain Resilience — Research suggest that bilingual brains are more resistant and resilient to the damage caused by dementia, meaning it can compensate for brain damage more effectively.
• Cognitive Reserve — Research suggest that bilingualism, or second language learning, is considered a form of cognitive stimulation which strengthens connections in the brain and reorganises the brain’s circuits. This increased cognitive reserve allows the brain and mind to better cope with ageing and damage caused by diseases like dementia, potentially delaying the onset of its symptoms.
• Delayed Onset of Symptoms — Research suggest that bilingual individuals may experience a delay of several years in the onset of dementia compared to monolingual individuals. Most studies indicate a delay of up to four to five years.
It is important to note that there is no guaranteed prevention and the connection between dementia and bilingualism remains a controversial debate, and the results from these studies may have inconsistencies, yet most tend to suggest that second language learning is associated with improvement in cognitive reserve, working memory, and increased functional connectivity. However, even when not considering the possible link to dementia or the delay of dementia symptoms, second language learning in itself can improve cognitive functions, such as attention and memory, which make it a worthwhile hobby to engage in.
Further Reading and Resources
• Alzheimer’s Society: Bilingualism and dementia
A helpful overview discussing how speaking more than one language may affect dementia risk and cognitive reserve.
• John Grundy’s 2020 Meta-analysis (Journal of Neurolinguistics)
For readers who would like to explore the research in more depth.
A profile of Dr. Bialystok’s groundbreaking research and its implications for ageing and dementia.
• Frontiers in Psychology – “The Impact of Bilingualism on Brain Reserve and Cognitive Reserve”
An open-access article exploring how bilingualism supports brain function and resistance to dementia.
• Memrise blog: Language learning and brain health
A lighter take on how learning a new language supports cognitive function (with appropriate scepticism, as noted in your article).
