New research from Edinburgh University has provided more evidence to suggest that learning an additional language could help delay the onset of dementia.

Five hours a day

Thomas Bak, a neuroscientist at the university, found that even attempting to learn a second language for as little as five hours a week could have positive effects.

Bak discovered that those who did practice a second language for at least five hours a week were able to delay the onset of frontotemporal dementia by six years, Alzheimer’s by 3.2 years and stroke-related dementia by 3.7 years.

When compared with the findings of drugs that aim to delay the onset of dementia, it seems a second language had a greater effect in halting the onset of the condition.

“Compared with anything that drugs can do, these are very long periods,” Bak said.

The Brain’s extra reserve tank

Bak’s research is not the first to look into the effects of bilingualism and its ability to delay the onset of dementia.

In 2011, Ellen Bialystok, a psychologist at York University in Toronto, undertook a similar experiment to that of Bak’s. She studied 102 bilingual and 109 bilingual subjects all who were likely to develop Alzheimer’s later in life.

She discovered that on average, bilingual patients were diagnosed with Alzheimer’s 4.3 years later compared to those with only one language. Furthermore, the reported onset of symptoms occurred 5.1 years later compared to the monolingual patients.

As to why this was the case, Bialystok referred to bilingualism as an extra “reserve tank” for the brain:

“It is rather like a reserve tank in a car. When you run out of fuel, you can keep going for longer because there is a bit more in the safety tank,” she said.

“We know that this system deteriorates with age but we have found that at every stage of life it functions better in bilinguals. They perform at a higher level. It won't stop them getting Alzheimer's disease, but they can cope with the disease for longer."

Other research

Another famous study was conducted by psychologist Judith Kroll from Penn State University. She studied the cognitive abilities of those who could speak more than one language compared to those who were monolingual.

By testing the patients on various mental tasks, such as editing out irrelevant information, she found the bilingual patients always outperformed the monolingual ones.

"We would probably refer to most of these cognitive advantages as multi-tasking," she said.

"Bilinguals seem to be better at this type of perspective-taking."

Kroll’s findings conflict with earlier beliefs that speaking more than one language may, in fact, have a damaging effect on the brain due to the possibility of causing it unnecessary confusion. Combined with other findings like that of Bialystok and Bak, this theory is now commonly believed to be false.

"The received wisdom was that bilingualism created confusion, especially in children. The belief was that people who could speak two or more languages had difficulty using either. The bottom line is that bilingualism is good for you,” said Kroll.