Association Between Dietary Animal Protein and Depression in a General Population

Background/Objectives: Because of conflicting evidence about the effects of protein sources on mental health, this study aimed to investigate whether animal or plant protein intake is associated with depression. Methods: Among 17,125 adults (7287 men and 9838 women) from nationally representative survey data, the primary measure of depression was determined with the Patient Health Questionnaire-9. A 24-h recall method was employed for dietary assessment. The associations between tertile ranges of animal or plant protein and depression were analyzed with weighted logistic models, adjusted for potential confounders. Results: Despite no association among men, women in the uppermost tertile of animal protein intake demonstrated a 36% lower likelihood of having depression [95% confidence interval 0.48–0.86]. Additionally, participants older than 65 years presented a significant trend toward lower likelihoods of depression associated with animal protein intake. Conclusions: This large cross-sectional study of the general population revealed that, regarding one of the common psychological disorders—depression—animal protein intake might have a beneficial association.