Associations between dietary patterns and depression and anxiety in middle-aged adults: A large cross-sectional analysis among Iranian manufacturing employees

Abstract

Background: Workers have to spend a substantial proportion of their income on foods and despite the high prevalence of stress among them, little is known about the association of dietary patterns and mental health disorders in this group. We examined whether dietary patterns are associated with depression and anxiety risk in the Iranian workers of steel mill company. Materials and Methods: We conducted a cross-sectional study among 3060 workers (2803 males and 260 females) in 2015. Dietary intake was assessed using a validated semiquantitative food frequency questionnaire during the preceding year, and depression and anxiety were evaluated using a Persian-validated Hospital Anxiety and Depression Scale. Major dietary patterns were determined using exploratory factor analysis and the risk of depression and anxiety was assessed across the tertiles of dietary patterns using logistic regression. Results: Three dietary patterns were identified: healthy (loaded by fruit, vegetables and skim dairy products), Western (loaded by processed foods, butter and sweets), and Iranian traditional diet (loaded by refined grains, red meat, poultry and legumes). After adjustment for various confounders, individuals in the highest tertile of healthy diet had lower risk of depression (odds ratio [OR]: 0.47; 95% confidence interval [CI]: 0.32, 0.68) and anxiety (OR: 0.71; 95% CI: 0.52, 0.99) compared with those in the first tertile, whilst greater adherence to the Iranian traditional diet was associated with increased risk of depression (OR: 1.82; 95% CI: 1.24, 2.67) and anxiety (OR: 1.50; 95% CI: 1.08, 2.09). The Western-style diet was marginally associated with increased risk of depression, but not anxiety. Conclusion: Overall, we found healthy diet might be associated with decreased risk of depression and anxiety, but the Iranian traditional diet might be associated with increased risk of depression and anxiety. Therefore, to improve public health, Iranian traditional diet should be adjusted according to the healthy diet recommendations.