Grundy and colleagues find meaningful results in bilingual study

John Grundy and his colleagues hope to share the positive effects of bilingualism on delaying dementia symptoms.

Rory Mcdermott

Learning another language can be difficult, but the rewards are plentiful for those who take on the challenge. New meta-analysis results support an often disputed topic 一 bilingualism effects on the development of dementia.

“Bilinguals tend to show symptoms of the disease much later than monolinguals — about four to six years later,” John Grundy, assistant professor of psychology at Iowa State, said. “So there’s something about the bilingual experience that rewires the brain and allows bilinguals to withstand the neural pathology in the brain for longer periods of time than monolinguals.”


Grundy and his colleagues are interested in the field of cognitive reserve, which relates to the brain’s ability to fight off damage or declining functionality. Specifically, they focused on bilingualism’s relationship with dementia, which became a hot topic among psychologists.

“Eventually, if you live long enough, most of us are going to show some signs of cognitive decline,” he said. “There aren’t very many pharmaceutical options in order to help us with that decline.”

Grundy also said recent studies led to contradicting views on bilingualism’s ability to prevent dementia. However, their results don’t differ from other research, they simply paint a different picture.

Bilingualism pushes symptoms back, but doesn’t prevent 

Grundy said these issues came from the misconception that bilingualism can prevent dementia. This result, although desirable, is inaccurate; instead, bilingualism can push back symptoms of dementia by many years.

“My colleague and I decided to go ahead and review a better analysis including both types — incidence rates and age of acquisition of dementia,” Grundy said. “We found very, very strong evidence that [age of acquisition] is an extremely robust effect.”


First, the researchers found these results exist across populations with different socioeconomic standing, cultures and backgrounds.

Second, the findings point to a direct course of action: promoting bilingualism to all people. Grundy noted how bilingualism benefits all fields, including sociolinguistics, cultural studies and business.

“This is of interest not only to cognitive neuroscience that’s studying aging, but also of interest to the general population,” said John Anderson, co-investigator of Grundy’s, from the Centre of Addiction and Mental Health in Toronto.

More research ahead 

Further work is yet to be done in a field with much left to discover. Anderson cited many ways this research can continue to be performed, focusing on details within subgroups.

“What would be interesting is to take a more nuanced perspective and say…what kind of bilinguals or what kind of bilingualism, rather, leads to the maximization of that effect?” Anderson said.

Potential research ideas include the frequency of using each language, the age of language acquisition and if switching between languages regularly contributes to the effect.

Grundy and Anderson’s findings prove fascinating for current and future bilinguals and those considering adding a language to their repertoire. The two hope to promote this cause after the meaningful conclusion to a detailed project.

“I wasn’t absolutely certain that we would find the effect, and I tried to be objective…and say, whatever the results are, the results are,” Anderson said.

As for the success, Anderson said, “It’s actually quite gratifying.”