Evidence for bilingualism as a cognitive reserve factor in biomarker-confirmed Alzheimer’s disease
INTRODUCTION: Bilingualism is a proposed cognitive reserve factor that delays symptom onset in Alzheimer's disease (AD), though current evidence lacks biomarker confirmation. This retrospective study examined bilingualism's association with symptom onset across AD clinical stages, including biomarker-confirmed cases. METHODS: Participants from the Sant Pau Memory Unit spanning amnestic mild cognitive impairment (MCI), amnestic dementia, and biomarker-confirmed AD were analyzed, with balanced representation of active and passive Spanish-Catalan bilinguals. Linear regression models evaluated associations between bilingualism and reported age at symptom onset, controlling for education, sex, and disease severity. RESULTS: s < .05). Higher education was associated with earlier onset, likely representing healthcare seeking behavior. DISCUSSION: Bilingualism protects against earlier symptom manifestation in MCI and AD, supporting bilingualism as a contributor to cognitive reserve.
Authors
- Miguel Santos‐Santos (ORCID: https://orcid.org/0000-0003-1567-617X)
- Stephanie M. Grasso (ORCID: https://orcid.org/0000-0001-5287-3012)
- Isabel Barroeta (ORCID: https://orcid.org/0000-0003-2764-7923)
- Nuole Zhu (ORCID: https://orcid.org/0000-0002-0015-9455)
- Alexandre Bejanin (ORCID: https://orcid.org/0000-0002-9958-0951)
- Wenfu Bao (ORCID: https://orcid.org/0000-0001-9519-9670)
- Javier Arranz (ORCID: https://orcid.org/0000-0003-0891-1215)
- Jesús García-Castro
- Elena Vera-Campuzano (ORCID: https://orcid.org/0000-0003-1189-0160)
- Isabel Sala
- Lídia Vaqué-Alcázar
- Sara Rubio-Guerra
- Judit Selma-González
- María Carmona-Iragui
- Sonia Karin Marques-Kiderle
- Lucia Maure-Blesa
- Natalia Casart Munoz
- Ignacio Illan-Gala
- Marco Calabria
- Juan Fortea
- Olivia Belbin
- Inigo Rodriguez-Baz
- Daniel Alcolea
- Laura Videla
- Alberto Lleo
Institutions
- Universitat Autònoma de Barcelona (ES)
- Universitat Oberta de Catalunya (ES)
- Hospital de Sant Pau (ES)
- Biomedical Research Networking Center on Neurodegenerative Diseases (ES)
- The University of Texas at Austin (US)
Publication Details
- Journal
- medRxiv
- Published
- 2026-04-02
- DOI
- https://doi.org/10.64898/2026.03.31.26349879
- Primary Topic
- Dementia and Cognitive Impairment Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Alzheimer's Association
- European Commission
- National Institutes of Health
- Instituto de Salud Carlos III
- National Institute on Aging