A Canadian study found that immigrants had 30% lower odds of being diagnosed with an anxiety disorder than Canadian-born adults. The study was published in the International Journal of Environmental Research and Public Health.
Anxiety disorders are among the most commonly diagnosed disabilities around the globe. Previous research suggests that the risk for anxiety disorders varies according to demographic, socio-economic, and health-related factors. Interestingly, despite the fact that immigrants face certain hardships and unique disadvantages compared to nonimmigrants, new research has found that immigrants show lower rates of anxiety.
“Our research team is interested in analyzing Canadian Longitudinal Study on Aging data to examine factors which affect mental health,” said Karen Davison, North American Primary Care Research Group Fellow and Health Science Program Chair at Kwantlen Polytechnic University in Surrey, who led the study.
“Given that anxiety disorders have such a high global burden related to disability, we were particularly interested in examining various social, economic, health, and nutrition-related factors and their relationships with the condition. This information could help to improve health practices, programs, and policies for adults.”
Davison and her team conducted a study to explore the relationship between immigrant status and anxiety disorders with a focus on older adults. They further explored nutritional and health-related factors that might mitigate the risk for anxiety disorders among all Canadians.
The researchers analyzed baseline data from the ongoing Canadian Longitudinal Study on Aging, resulting in a sample of 26,991 Canadian residents between the ages of 45-85. The survey measured self-reported lifetime anxiety disorder with the question, “Has a doctor ever told you that you have an anxiety disorder such as a phobia, obsessive-compulsive disorder or a panic disorder?” The study also included various demographic, economic, health, and nutritional measures.
Across the sample, 8.5% of respondents reported being diagnosed with an anxiety disorder at some point in their lifetime. Interestingly, while 9% of Canadian-born respondents reported an anxiety diagnosis, only 6% of immigrants did. When accounting for age and sex, this represented 30% lower odds of being diagnosed with anxiety for immigrants.
The authors offered several explanations for what researchers call the “healthy immigrant effect.” Canada uses a points-based immigration system, which classifies a person’s eligibility to immigrate to Canada according to their skills and qualifications. Those accepted to immigrate generally have a higher education and better work experience, qualities that may lessen their susceptibility to anxiety disorders.
“Another potential explanation … is that potential immigrants with anxiety disorders would find the challenges of relocation too anxiety inducing and would therefore not choose to immigrate,” the authors wrote.
Certain health factors impacted the likelihood of an anxiety disorder diagnosis. Having at least one existing health condition, experiencing chronic pain, being categorized as underweight, having a higher percentage of body fat, or smoking 100 or more cigarettes over one’s lifetime were each associated with increased odds of being diagnosed with anxiety.
Nutritional factors also impacted reports of anxiety. Across the sample, those who consumed two or more fiber sources a day or one or more pastries a day were more likely to be diagnosed with an anxiety disorder. Alternatively, those who consumed 0.5 to 2 sources of pulses and nuts per day or three or more sources of fruit and vegetables per day were less likely to have anxiety. This may be because fruits, vegetables, and nuts contain high levels of zinc, magnesium, and vitamin B, which have been associated with reduced anxiety.
“We believe the main message of this study is that after accounting for many social, economic, health, and nutrition-related factors, a significant relationship was found between fruit and vegetable intakes and having been diagnosed with an anxiety disorder. It is well established that fruit and vegetable intakes are associated with physical health. This study lends to the increasing evidence that shows there are also links with mental health,” Davison told PsyPost.
“In this study we found that lower intakes of calcium rich foods with high vitamin D content are associated with lower odds of anxiety disorders. However, as the number of sources consumed increased, the trends in the odds ratios showed what seemed to be a positive or dose-response type relationship. For future studies we would like to examine supplement sources of calcium and vitamin D which are commonly taken by older adults and their relationship with anxiety disorders. In addition, for future work we plan to examine biomarkers and genomic markers related to calcium and vitamin D which may help us to better understand these relationships.”
“Another finding we would like to highlight is the associations we found with higher percent body fat and anxiety. This relationship may be due to mechanisms related to immune-inflammatory activation. Previous research has shown that individuals with high body fat and mental ill health have increased inflammatory markers, such as C-reactive protein, interleukin-6, and tumour necrosis factor-alpha. The activation of certain immune system cells in response to ongoing chronic inflammation, has been linked with poor mental health. Certainly more research is needed to better understand the possible links between body composition and anxiety,” Davison added.
The authors concluded that their findings offer insight into nutritional, health-rated, and social factors associated with anxiety disorder diagnoses among immigrants and Canadian-born residents of Canada. These insights could help inform treatment for middle age and older adults with anxiety.
The study, “Nutritional Factors, Physical Health and Immigrant Status Are Associated with Anxiety Disorders among Middle-Aged and Older Adults: Findings from Baseline Data of The Canadian Longitudinal Study on Aging (CLSA)”, was authored by Karen M. Davison, Shen (Lamson) Lin, Hongmei Tong, Karen M. Kobayashi, Jose G. Mora-Almanza, and Esme Fuller-Thomson.
