Learning another language may be a way to avoid dementia, according to a new study.

In a study examining the link between language and the brain-destroying disease, neurologists found that people who spoke two languages developed dementia 4 1/2 years later than those who spoke just one language. This finding held up even in illiterate people, the Los Angeles Times reported.

"Bilingualism combines a lot of different mental activities," Thomas Bak, neurologist and co-author of the study, said in a statement. "You have to switch sounds, concepts, grammatical structures, cultural concepts. It stimulates your brain all the time."

Brain stimulation may help protect from the onset of dementia.

The researcher's findings are the first to report an advantage of speaking two languages in people who are unable to read, "suggesting that a person's level of education is not a sufficient explanation for this difference," Dr. Suvarna Alladi, researcher at Nizam's Institute of Medical Sciences in Hyderabad, India, said in a statement.

For the study, researchers reviewed medical records of 648 people with dementia in the city of Hyderabad; 391 of them were bilingual. The average age of the participants was 66.

Researchers found people who were bilingual developed their first symptoms of dementia, such as memory loss and confusion, at an average age of 65.6 - five years later than the average of 61.1 for people who spoke just one language, the Los Angeles Times reported.

The differences were seen in several types of dementia, including Alzheimer's disease, vascular dementia, associated with poor blood flow to the brain, and frontotemporal dementia, which is caused by degeneration of the brain's frontal or temporal lobes.

Alladi said location was key when it came to this study; most residents of the city often spoke two or three languages.

"Since bilingualism is more of a norm in India, bilingualism is not a characteristic of any particular socioeconomic, geographic or religious group," she said in a statement.

The researchers found that a person didn't get additional advantage by speaking three or more languages.

The study is the largest to date to document the delay of dementia in bilingual people

"These results offer strong evidence for the protective effect of bilingualism against dementia in a population very different from those studied so far in terms of its ethnicity, culture and patterns of language use," Alladi said in a statement.