BACKGROUND: Recent evidence suggests that diet composition is a key biological factor related to the development of depressive disorders. The present study was conducted to investigate the animal and plant protein intake and their replacement in association with depression, anxiety, and stress in Iranian adults. METHOD: In this cross-sectional study, the dietary intake of 7169 subjects were assessed using a validated food frequency questionnaire. The depression, anxiety, and stress Scale - 21 (DASS-21) questionnaire was used to psychological disorders. Logistic regression was used to obtain odds ratios for depression, anxiety, and stress across quintiles of animal and plant protein. RESULTS: The participants' age range was 20-69 years. Individuals with the highest animal protein consumption had a lower chance for developing depression compared to those with the lowest intakes (OR = 0.73, 95%CI: 0.59-0.90
P CONCLUSION: Animal protein intake might lower the odds of depression and anxiety particularly. Future prospective investigations are proposed to confirm these findings.