Monolingual Aging Penalty: Learn Another Language!

I posted a few months ago about this study in Catalonia I'm tracking related to dementia and bilingualism. Another study dropped in Nature Aging last week in the same vein, claiming "Multilingualism protects against accelerated aging." Here's the layman's summary:

• Researchers studied over 86,000 people across 27 European countries to see how different factors affect aging. They created “biobehavioral age gaps” to measure whether people are aging faster or slower than expected.
• Positive factors like good education, cognition, and functional ability were linked to slower aging, while risks like cardiometabolic issues, sensory impairments, and being female were linked to faster aging.
• Speaking multiple languages (multilingualism) appeared protective: it reduced the risk of accelerated aging, even when accounting for social, physical, and country-level differences, while monolingual people had higher risk.
  • The effect is more pronounced with each additional language.

My understanding is that researchers pegged participants at a predicted age given a combination of factors (see positive/risks in bullet 2). If your actual age is higher, you are aging slower than expected. If your actual age is lower, you are aging faster than expected.

So then for multilingualism: people who speak multiple languages tend to have a biobehavioral age that is younger than their actual age, meaning their bodies and minds show signs of slower aging. In contrast, people who speak only one language tend to have a biobehavioral age that is older than their actual age, showing faster aging.

Correlation != causation and blah blah blah...go pick up some flashcards...