Knowing more than one language could lower the odds of having an older than expected health profile.
The study, published in the journal Nature Aging, found that “speaking two, three or more additional languages” in addition to your mother tongue was “associated with a consistently protective effect that became more pronounced with increasing age”.
Being bilingual revealed only a “modest” advantage, suggesting the more languages you speak the better.
Experts from Spain and South America used survey data from 86,149 people aged between 51 and 90 in 27 European nations.
Their actual ages were compared to their “biological age” based on various lifestyle factors used to assess their cognitive and “functional” abilities.
They also assessed their levels of physical activity and history of medical conditions including heart disease and diabetes.
Their weight, alcohol consumption and sleep quality were also taken into account.
“The authors show that multilingualism is linked to slower ageing, and monolingualism is linked to accelerated ageing.
"In short, knowing more than one language lowers the odds of having an older than expected health profile at a given moment as well as the risk of developing one later,” an independent analysis by authors not linked to the study reads.
Results revealed that those who spoke more than one language were likely to have a smaller “gap” between their real and their biological age.
Meanwhile, those spoke just one language had a higher chance of having an older biological age older than their real age, suggesting that they were ageing badly.
Jason Rothman and Federico Gallo, from the Brain and Bilingual Experience Lab at Lancaster University, wrote in the independent analysis: “Knowing more than one language might not simply enable you to speak with more people or open new cultural horizons — it is possible that it helps you to age more healthily.
“The hypothesis that the mental gymnastics inherent to juggling multiple languages is one lifestyle factor that fosters healthier cognitive ageing.”
Christos Pliatsikas, a cognitive neuroscientist at the University of Reading, said the results could “bring a step change to the field”.
"The effects of multilingualism on ageing have always been controversial, but I don’t think there has been a study of this scale before, which seems to demonstrate them quite decisively," he said.
Previous research has suggested speaking multiple languages can improve cognitive functions such memory and attention, which strengthens brain health as we get older.
But much of these studies have relied on smaller sample sizes and have used unreliable methods to measure ageing, which critics say has produced inconsistent results.
