Associations of multilingualism and language proficiency with cognitive functioning: epidemiological evidence from the SwissDEM study in community dwelling older adults and long-term care residents

Background We explored whether number of languages spoken and language proficiency are associated with cognitive performance among older adults living in the community and in long-term care (LTC) in Switzerland. Methods Among study participants, 664 lived in the community in the Canton of Zurich (Mean age = 72.97 years; SD = 6.08), 386 lived in the community in Ticino (Mean age = 76.24 years; SD = 6.66), and 176 resided in LTC in Ticino (Mean age = 87.61 years; SD = 6.45). We recorded sociodemographic variables, number of languages spoken, language proficiency, and assessed overall cognitive performance, immediate and delayed memory, and verbal fluency with standardized tests. We used adjusted regression models. Results A higher number of spoken languages was positively associated with overall cognitive performance, verbal fluency and immediate and delayed memory performance in community-dwelling older adults in the Cantons of Ticino and Zurich, (all p values ≤ 0.012;), but not in in older adults living in LTC homes (all p values ≥ 0.35). Higher language proficiency was associated with better memory performance among individuals living in the community in Ticino (p value = 0.003), and to better performance in verbal fluency and memory tasks in Zurich (p values ≤ 0 .002). Among LTC residents, proficiency levels were not associated with cognitive performance. Conclusions Multilingualism and greater language proficiency were associated with better cognitive functioning in community-dwelling but not in institutionalized older adults. Multilingualism may contribute to cognitive reserve, as well as protect and delay cognitive decline in late life.