Learning a second language could help stave off dementia for many years, scientists have revealed.
It’s long been established that bilingual people develop dementia an average of 5.4 years later than those that can only speak their first language, regardless of other factors such as job and education.
But the reason why this skill serves such a significant benefit has long puzzled experts.
Now MRI imaging studies have given scientists a better idea of what is happening in the brain of those who speak more than one language.
Findings showed that the benefits are due to the fact speaking another tongue increases the size of the brain, Natalie Phillips at McGill University in Montreal, told New Scientist.
She explained that research has shown a person with a greater brain reserve or size can sustain more damage before reaching a threshold which triggers dementia.
People who are bilingual have more cells in language areas of the brain and an increased volume in areas associated with learning and emotion.
Speaking another language has also been shown to increase the efficiency and adaptability of the brain. So if the brain does shrink as a result of dementia, the organ can use different pathways to access the same information, Phillips said.
It’s thought that bilingual people develop dementia 5.4 years later than those that can only speak their first language, regardless of their education, occupation, sex or immigration status
It’s thought the constant switching between languages strengthens aspects of cognitive reserve known as executive functions, which are responsible for decision-making, planning and attention.
In September, Phillips’ team showed a link between being bilingual and brain maintenance — which is what keeps the brain healthy when faced with the consequences of disease.
The 2024 study looked at both bilingual and monolingual people who had early or late stage Alzheimer’s. Researchers also looked at people who felt their memory was getting worse but did not have dementia.
MRI scans showed bilingual dementia patients had far less decline in activity in the hippocampus — a part of the brain that helps with learning and memory — compared to one-language participants.
However, researchers noted there was no difference in the size of this brain region, suggesting knowing two languages helps to reinforce the memory centre of the brain rather than it increasing in size.
‘It doesn’t prevent dementia, it holds back the flood,’ said Ellen Bialystok at York University in Toronto.
‘When bilingual people eventually show cognitive problems, they decline faster, but it starts later. Imagine what families could do with that extra time.’
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss
Around 900,000 Brits are currently thought to have the memory-robbing disorder. But University College London scientists estimate this will rise to 1.7million within two decades as people live longer. It marks a 40 per cent uptick on the previous forecast in 2017
However, studies show that only 10 per cent of Brits can speak more than one language. Yet experts say it’s never too late.
In fact, learning a new language in adulthood still provides a boost to brain health, according to Victoria Marian, who studies multilingualism at Northwestern University in Evanston, Illinois.
The longer you can speak a second language for, the more your brain will be stimulated, experts say.
There are currently around 982,000 people with dementia in the UK, according to The Alzheimer’s Society.
This number is expected to rise to 1.4 million by 2040.
However, about 40 per cent of dementia cases are thought to be preventable, according to the NHS.
Experts say making lifestyle changes such as losing weight, doing more exercise or giving up smoking, could ward off the condition.
