The influence of dietary patterns and stressful life events on psychological problems in a large sample of Iranian industrial employees: Structural equations modeling approach

Background: Psychological problems affect many employees and their job performance. Although, the association of diet and stress, as modifiable risk factors, with psychological problems have been investigated separately, however their simultaneous impacts have not been studied. The present study aimed at reinvestigating the association of major dietary patterns and stressful life events with intensity of psychological problems in a large sample of Iranian industrial employees. Methods: In a cross-sectional study, 3063 employees in an industrial unit in Isfahan, Iran were investigated. Psychological problems profile as a latent construct was extracted from three common psychological problems; depression, anxiety and psychological distress. Depression and anxiety were measured by Persian validated version of Hospital Anxiety and Depression Scale (HADS) and psychological distress by the 12 items General Health Questionnaires (GHQ). Major dietary patterns were derived from a validated short form of semi-quantitative Food Frequency Questionnaire (FFQ) using explanatory factor analysis. Stressful life events dimensions were extracted based on factor analysis, from self-perceived frequency and intensity of Stressful Life Events (SLE) questionnaire. Associations of the obtained factors were investigated in a latent structural modeling framework. Results: Three dietary patterns i.e. western, traditional and healthy and two stressors dimensions including personal life and socioeconomics were extracted. Greater adherence to healthy diet was protectively associated with psychological problems profile scores (beta=-0.54; 95% CI:-0.74,-0.34). Adherence to western (beta= 0.23; 95% CI: 0.02, 0.45) and Iranian traditional (beta= 0.48; 95% CI: 0.28, 0.68) dietary patterns were positively associated with higher psychological problems scores in employees. But after adjustment for life stressors only adherence to a healthy diet remained significantly associated with psychological problems profile (beta=-0.43; 95% CI:-0.59,-0.27). Also, personal life stressors (beta= 0.81; 95% CI: 0.63, 0.99) and socioeconomics stressors (beta= 0.12; 95% CI: 0.08, 0.16) had significantly direct association with psychological problems profile scores. Limitations: Variables assessment by self-reported questionnaires, not affording causality because of cross sectional design, not adjusting the nutrients intake in association analyses, relatively small sample size of women. Conclusions: Life stressors particularly personal stressors have negative direct association with psychological health of employees. Adherence to a healthy diet can be related to improvement of psychological health in employees. The results can be useful in occupational health planning in order to improve mental health and job productivity.