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If becoming fluent in a second language is on your bucket list, a recent study co-authored by John Grundy, assistant professor of psychology at Iowa State University, may compel you to immediately register for an introductory language course.

In May 2020, Grundy and co-authors John Anderson, Centre for Addiction and Mental Health, Toronto, Canada, and Kornelia Hawrylewicz, Department of Psychology at York University, Toronto, Canada, published “Does Bilingualism Protect Against Dementia? A Meta-analysis” in Psychonomic Bulletin and Review. In the study, the team investigates whether bilingualism delays the onset of Alzheimer’s disease. In short, the answer is yes.

Data analysis

Grundy and his team meticulously reviewed more than 20 existing studies, controlling for factors like socioeconomic status, intelligence, education and geographic location, to determine whether the onset of Alzheimer’s disease symptoms is slower to develop in bilingual individuals versus people who speak only one language, or monolinguals.

Through a meta-analysis of the data, the researchers discovered that the symptoms of Alzheimer’s disease are halted by up to five years, on average, in people who fluently speak more than one language. The study did not substantially show that bilingualism deters Alzheimer’s disease incidence rates; only that it helps to delay symptoms.

“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,” Grundy said. “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.”

In the study, Grundy notes that bilingualism does not prevent or reverse Alzheimer’s disease. Instead, it’s a form of cognitive reserve, like a demanding career or exercise, that strengthens and reorganizes the brain’s circuits, helping to fight off the initial symptoms of dementia until later in life. The authors state that bilinguals rely on the posterior and subcortical regions of the brain for more efficient processing of information than monolinguals, who depend on the brain’s more demanding frontal circuits as they age, thus exacerbating the onset of dementia.

Help for health care

Strained health care systems spurred Grundy’s motivation to pursue this study. The World Health Organization reports that dementia affects more than 50 million people worldwide with nearly 10 million new cases diagnosed each year. Alzheimer’s disease is the most common form of dementia and accounts for up to 70% of cases.

“Alzheimer’s disease places a significant burden on the health care system. It’s extraordinarily expensive,” Grundy said. “The importance of doing the study was inspired by how we can inform people of ways to remove a little of the burden from the health care system.”

He believes bilingualism may be part of the answer. Learning a second language is difficult and makes the brain work harder. Using multiple languages challenges the mind, creating new neural pathways when others begin to fade with age.

“Think about taking a new path home,” Grundy said. “The first time you take that path it’s going to be difficult to remember it, and maybe that’s true the second and third time. But eventually, it gets easier, and you then have multiple pathways to get to the same outcome. You can think about bilingualism like that as well.”

Never too late

So, is there hope for monolinguals climbing the steep hill of middle age to still combat the onset of dementia? Grundy thinks so.

“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,” Grundy said. “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.”