Later-life cognitive impairment is an important health issue; however, little is known about the condition among diverse groups such as immigrants. This study aims to examine whether the healthy immigrant effect exists for verbal fluency, an indicator of cognitive functioning, among anglophone middle-aged and older adults in Canada.
Using from the baseline data of the Canadian Longitudinal Study on Aging (CLSA), multiple linear regression was employed to compare associations among immigrants (recent and long-term) and Canadian-born residents without dementia for two verbal fluency tests, the Controlled Oral Word Association Test (COWAT) and the Animal Fluency (AF) task. Covariates included socioeconomic, physical health, and dietary intake.
Of 8,574 anglophone participants (85.7% Canada-born, 74.8% aged 45–65 years, 81.8% married, 81.9% with a post-secondary degree), long-term immigrants (settled in Canada >20 years) performed significantly better than Canadian-born residents for the COWAT (42.8 vs 40.9) but not the AF task (22.4 vs 22.4). Results of the multivariable adjusted regression analyses showed that long-term immigrants performed better than Canadian-born peers in both the COWAT (B=1.57, 95% CI: 0.80–2.34) and the AF test (B=0.57, 95% CI: 0.19–0.95), but this advantage was not observed among recent immigrants. Other factors associated with low verbal fluency performance included being single, socioeconomically disadvantaged, having hypertension, excess body fat, and consuming low amounts of pulses/nuts or fruit/vegetables.
Long-term immigrants had higher verbal fluency test scores than their Canadian-born counterparts. Immigration status, social, health and nutritional factors are important considerations for possible intervention and prevention strategies for cognitive impairment.
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Availability of data and material: Data are available from the Canadian Longitudinal Study on Aging (https://www.clsa-elcv.ca) for researchers who meet the criteria for access to de-identified CLSA data.
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This research was made possible using the data collected by the Canadian Longitudinal Study on Aging (CLSA). Funding for the Canadian Longitudinal Study on Aging (CLSA) is provided by the Government of Canada through the Canadian Institutes of Health Research (CIHR) under grant reference: LSA 9447 and the Canada Foundation for Innovation. This research has been conducted using the CLSA Baseline Comprehensive Dataset version 4.0, under Application ID 170605. The CLSA is led by Drs. Parminder Raina, Christina Wolfson and Susan Kirkland. The development, testing and validation of the Short Diet Questionnaire (SDQ) were carried out among NuAge study participants as part of the CLSA Phase II validation studies, CIHR 2006–2008. The NuAge study was supported by the CIHR, Grant number M0P-62842, and the Quebec Network for Research on Aging, a network funded by the Fonds de Recherche du Québec-Santé. The opinions expressed in this manuscript are the authors’ own and do not reflect the views of the Canadian Longitudinal Study on Aging.The authors declare that they have no competing interests.
Funding: Part of this study was funded through E.F.T.’s Sandra Rotman endowed chair funds and K.M.D.’s Fulbright Canada Research Chair.
Conflict of interest: We have no conflict of interest to declare.
Ethical Standards: The secondary analysis of CLSA data conducted in this paper was approved by the University of Toronto’s Health Sciences Research Ethics Board (protocol number: 34065).
Disclaimer: The opinions expressed in this manuscript are the author’s own and do not reflect the views of the Canadian Longitudinal Study on Aging.
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Fuller-Thomson, E., Saab, Z., Davison, K.M. et al. Nutrition, Immigration and Health Determinants are Linked to Verbal Fluency among Anglophone Adults in the Canadian Longitudinal Study on Aging (CLSA). J Nutr Health Aging 24, 672–680 (2020). https://doi.org/10.1007/s12603-020-1402-8
- Executive function
- letter fluency
- semantic fluency
- Canadian Longitudinal Study on Aging (CLSA)
- dietary intake