Active bilingualism associated with better neuropsychological function and biomarker profiles in Alzheimer's disease compared to passive bilingualism.

This cohort study evaluated neuropsychological functioning and biofluid markers of brain health in Spanish-Catalan bilinguals with Alzheimer's disease. The population consisted of 280 active bilinguals and 287 passive bilinguals. The primary comparison focused on the impact of active versus passive bilingualism on cognitive performance and biological markers.

Active bilinguals outperformed passive bilinguals across neuropsychological domains, including attention/executive functions, language, and visuospatial/visuomotor functioning. Additionally, active bilinguals exhibited significant differences compared to passive bilinguals regarding cerebrospinal fluid and plasma biomarkers of amyloid burden and neuroinflammation. No adverse events, discontinuations, or specific safety data were reported in the study.

The study highlights the importance of capturing bilingualism in aging cohorts to understand how lifestyle factors shape neurodegenerative disease expression. However, biological mechanisms through which bilingualism exerts protective effects remain poorly understood. Consequently, these results should be interpreted as observational associations rather than definitive causal protections.

Clinicians should recognize the potential value of bilingualism in aging populations while acknowledging that the specific pathways for neuroprotection are not yet fully elucidated. Further research is needed to clarify these mechanisms before drawing firm conclusions about clinical interventions.