Speaking Two Languages Could Delay Dementia

Bilingual individuals developed dementia symptoms later than those speaking one language

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) ¿Cómo estás? How are you? If those sentences are equally familiar to you, you may be bilingual. And that could mean good things for your aging brain.

A recent study found that people who spoke two languages tended to develop dementia later than those who spoke only one language.

But two was the limit — speaking more than two languages did not offer any additional benefit.

It did not matter if the people in the study could read or write. Even illiterate individuals seemed to benefit from speaking multiple languages.

Also, it was not clear whether it mattered which languages someone spoke.

"Embrace opportunities to learn a new language."

This study, led by Suvarna Alladi, DM, of the Department of Neurology at Nizam's Institute of Medical Sciences in Hyderabad, India, looked at whether being bilingual affected a person's risk of dementia.

The researchers reviewed the medical records of 648 patients who had diagnosed dementia. Among these patients, 391 were bilingual.

The researchers compared when each patient's dementia symptoms began.

They also considered how many languages each patient spoke, their level of education, their occupations and other characteristics that differed among the patients.

The researchers discovered that patients who spoke at least two languages developed dementia an average 4.5 years later than the patients who spoke only one language.

The later onset of dementia among bilingual speakers was true for those with Alzheimer's disease as well as other types of dementia.

Even among patients who could not read or write (were illiterate), dementia symptoms occurred later, on average, if they spoke two languages instead of one.

However, patients who spoke more than two languages did not have their symptoms delayed compared to those who spoke only two languages.

Therefore, the apparent benefit of speaking multiple languages appeared to stop with speaking two languages. Speaking more languages did not hurt or help.

The results in this study did not vary even when the researchers took into account differences among the patients' education, occupations, sex and hometown density (living in an urban area versus a rural area).

"This is the largest study so far documenting a delayed onset of dementia in bilingual patients and the first one to show it separately in different dementia subtypes," the researchers wrote.

"It is the first study reporting a bilingual advantage in those who are illiterate, suggesting that education is not a sufficient explanation for the observed difference," they wrote.

This particular study involved patients living in India, so the researchers suggested more research would be needed to investigate patients in other countries.

This study was published November 6 in the journal Neurology. The research was funded by the Department of Science and Technology at the Cognitive Science Research Initiative within the Government of India.

Other than other research funding from the Government of India, no potential conflicts of interest for the authors were reported.

Review Date: 
November 6, 2013
Last Updated:
December 30, 2013