An apple a day: Protective associations between nutrition and the mental health of immigrants in Canada.

Purpose: Mental illness represents a major public health burden among Canada's large immigrant population. A burgeoning cross-sectional, longitudinal, and experimental evidence base implicates nutrition in mental health. Healthier diets (e.g., those rich in certain micro-nutrients) may benefit cognitive, social, and emotional functioning through attenuated inflammation and other bio-psychological pathways. The present study examined associations between nutrition and three markers of mental health among immigrants to Canada.

Methods: Employing cross-sectional data from immigrant respondents (n = 37,071) to a nationally representative population-based survey (the Canadian Community Health Survey: CCHS 2011-2014), we modelled associations of daily fruit and vegetable consumption with three mental health outcomes: anxiety and/or mood disorder diagnosis, being distressed (assessed via the 6-item Kessler Psychological Distress Scale), and having good self-rated overall mental health. Multivariable logistic regression analyses were employed, adjusting for various socio-demographic and lifestyle-related variables.

Results: Higher consumption of fruit and vegetables demonstrated significant, protective associations with odds of having a mood and/or anxiety disorder, being distressed, and self-rated good mental health. Such patterns of association were similar regardless of ethno-cultural minority status and recency of immigration. Moreover, the protective associations of nutrition and mental health were independent of socio-demographic, health, and lifestyle factors.

Conclusions: Results suggested evidence of protective associations between healthy nutritional intake and mental illness among a large-scale sample of immigrants in Canada. Importantly, the protective associations of healthier diets with immigrants' mental health were independent of various markers of healthy lifestyles (e.g., general health status, physical activity, alcohol use). Healthy dietary intake may, therefore, be worth consideration in efforts to prevent mental illness among immigrants.