“A study that tracked hundreds of Scottish people for decades is the strongest evidence yet that speaking an extra language slows the mental decline that accompanies ageing. The benefits hold regardless of your IQ and even if you learn your second tongue as an adult.”  New Scientist

   https://www.newscientist.com/article/dn25671-learn-a-second-language-to-slow-ageing-brains-decline/

"Bilingualism delays onset of dementia"

"Researchers said the extra effort involved in using more than one language appeared to boost blood supply to the brain and ensure nerve connections remained healthy – two factors thought to help fight off dementia.

“We are pretty dazzled by the results,” Professor Ellen Bialystok of Toronto’s York University said in a statement."   New Scientist

   https://www.newscientist.com/article/dn10954-bilingualism-delays-onset-of-dementia/

"Bilingual brain boost: Two tongues, two minds.

Speaking a second language can change everything from problem-solving skills to personality – almost as if you are two people."    New Scientist

    https://www.newscientist.com/article/mg21428631-800-bilingual-brain-boost-two-tongues-two-minds/

“..learning a foreign-language may represent a potentially helpful cognitive intervention for promoting healthy aging.”

   https://www.frontiersin.org/articles/10.3389/fnins.2019.00423/full

“Enhanced cognitive performance after foreign language learning would indicate that learning a foreign language could enlarge cognitive reserve and thus promote healthy cognitive ageing in older adults."

   https://bmcgeriatr.biomedcentral.com/articles/10.1186/s12877-021-02051-x