The Spanish-English bilingual experience and cognitive change in Hispanics/Latinos from the Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging

INTRODUCTION: Studies suggest bilingualism may delay behavioral manifestations of adverse cognitive aging including Alzheimer's dementia. METHODS: Three thousand nine hundred sixty-three participants (unweighted mean population age ≈56 years) at Hispanic Community Health Study/Study of Latinos baseline (2008-2011) self-reported their and their parents' birth outside the United States, Spanish as their first language, and used Spanish for baseline and comparable cognitive testing 7 years later (2015-2018). Spanish/English language proficiency and patterns of use were self-rated from 1 = only Spanish to 4 = English > Spanish. Cognitive testing included test-specific and global composite score(s) of verbal learning, memory, word fluency, and Digit Symbol Substitution (DSS). Survey linear regression models examined associations between baseline bilingualism scores and cognition. RESULTS: Higher second-language (English) proficiency and use were associated with higher global cognition, fluency, and DSS at follow-up and better than predicted change in fluency. DISCUSSION: The bilingual experience was more consistently related to 7-year level versus change in cognition for Hispanics/Latinos.