How to age better by learning languages

A surprising article was published a few weeks ago in Nature This says a lot about how little we know about our brains. According to an analysis of blood markers in the general population of Norway, 25% of people over 85 have Alzheimer's. This figure was previously thought to be between 7% and 13%, so the study reveals that the disease is much more common than previously believed and often goes undetected. These data imply that the abnormal and accelerated aging of the brain that we associate with Alzheimer's may not be as rare as we would like to think, especially as life expectancy continues to increase—which in almost every country has been on an upward trend for over a century. That's why it's so important to find ways to delay the loss of brain function, which is typical of this disease. The decline in intellectual abilities that we see with age, both in healthy people and in those who will eventually develop dementia, depends mainly on two factors. The first is how quickly our brains age and degenerate, something we still can't accurately predict or measure. The second is what's called cognitive reserve, which is the intellectual capacity we've acquired over the years and which inevitably declines in the final stages of life. It could be compared to draining a bathtub: the time it takes to run dry depends on how quickly the water flows out (the first factor), but also on how full it was when we pulled the plug (the reserve we had).

That's why one of the factors believed to reduce the risk of Alzheimer's is having a high level of education—in other words, having filled the bathtub to the brim. In fact, the article we cited at the beginning also found that people with lower levels of schooling consistently had higher levels of one of the Alzheimer's markers, called p-tau217. But let's remember that more education alone isn't enough to prevent illness: if the bathtub empties quickly enough, it doesn't matter that it was full to begin with; that's why even great sages have ended up with dementia. Speaking more than one language is neuroprotective.

Another recent study reinforces this idea that exercising the mind can delay the effects of aging, but unexpectedly, not only in the brain, but throughout the entire body. The article, published in the journal Nature Aging A study by a group coordinated by neuroscientist Agustín Ibáñez of the University of San Andrés in Argentina presents data from over 86,000 people in 27 European countries, all considered healthy. Their chronological age was compared to an estimate of their biological age, measured using various general parameters. After adjusting for factors such as age, exposure to pollution—which is known to accelerate aging—and socioeconomic status, the researchers found that the factor most strongly associated with healthy aging—having a biological age equal to or lower than one's chronological age—was speaking more than one language. In fact, the more languages a person mastered, the better their health was, and this extended beyond simply protecting brain function.

Despite the difficulty of quantifying an organism's "real" age—we still lack sufficiently precise biomarkers—this study confirms previous findings, some dating back more than twenty years, which had already observed that speaking two or more languages, beyond its obvious cultural and social advantages, delays the onset of dementia. Furthermore, for the first time, multilingualism is linked to healthier aging of the entire body, not only as a strategy to increase cognitive reserve, which would provide a more general explanation for the protection against neurodegeneration previously observed. However, the study does not differentiate between the effect of learning languages in childhood versus adulthood, nor does it address what happens if one of these languages ceases to be used. Thus, those of us fortunate or unfortunate enough to have grown up in a bilingual environment would not only already have a slightly fuller brain than others, possibly due to all the effort our neurons made while learning to speak, but our aging process would also be improved. This could serve as an argument—if more were needed—against the strategy of states that, to reinforce their nationalist whims, want to impose a linguistic monoculture. Aside from ensuring the survival of minority languages, a sound long-term public health investment would be to encourage the learning of additional languages, perhaps especially during the ages when it is easiest to do so, when the brain is still developing. This would be cheaper and more comprehensive than intervening in other modifiable lifestyle factors, such as diet or exercise. None of this will replace the need to continue investing in research to find treatments that slow aging, but every little helps.