Psychological disorders and dietary patterns by reduced-rank regression

Objective To determine the relationship between dietary patterns identified by reduced-rank regression method and psychological disorders in a large group of Iranian adults. Methods A cross-sectional study was performed on 3363 Iranian adults between 20 and 55 years. Dietary intakes were assessed using a validated dish-based semi-quantitative food frequency questionnaire. Psychological health was examined through validated Iranian version of Hospital Anxiety and Depression Scale and General Health Questionnaires Reducedrank regression was applied to identify dietary patterns based on the ratio of omega-3/omega-6, zinc, magnesium, vitamin B6, and folic acid intake. Logistic regression was used to assess the relationship between dietary patterns and psychological disorders. Results Three major dietary patterns were derived: healthy, fish and poultry, and transitional. After adjustment for potential confounders, healthy was associated with reduced depression (odds ratio (OR) for the highest vs. lowest quintile: 0.35; 95% confidence interval (CI): 0.25-0.50), anxiety (OR: 0.47; CI: 0.30-0.74), and psychological distress (OR: 0.52; CI: 0.36-0.75). Greater adherence to the fish and poultry was related with lower odds of depression (OR: 0.64; CI: 0.47-0.87). Participant in the third quintile of fish and poultry dietary pattern were less likely to be anxious (OR: 0.61; CI: 0.41-0.91). Additionally, we found an inverse significant correlation between adherence to the transitional dietary pattern and odds of depression (OR: 0.36; CI: 0.21-0.62), anxiety (OR: 0.43; CI: 0.21-0.88), and psychological distress (OR: 0.41; CI: 0.23-0.72). Conclusion We found that healthy, fish and poultry, and transitional dietary patterns have inverse significant relationship with odds of psychological disorders, but prospective studies are needed for causal conclusion.