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. Reduced-rank 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.