Associations of Dietary Inflammatory and Antioxidant Indices with Mental Health Indicators Among University Students: A Cross-Sectional Study

<b>Background/Objectives:</b> Protecting students' mental health during university is essential for their future quality of life. Therefore, diet should be emphasized as a complementary and preventive strategy in supporting and maintaining mental health. This study aimed to examine the association between dietary inflammatory and antioxidant indices and mental health indicators (depression, anxiety, stress, and well-being) in university students. <b>Methods:</b> This cross-sectional study included 907 university students. We collected dietary data using a 24 h recall. Based on this data, we used 33 food parameters to calculate the Dietary Inflammatory Index (DII) and 6 antioxidant nutrients to calculate the Dietary Antioxidant Index (DAI). We evaluated mental health using the Depression, Anxiety, and Stress Scales-21 (DASS-21), and assessed well-being using the World Health Organization Five Well-Being Index (WHO-5). <b>Results:</b> Overall, 62.4% of participants reported symptoms of depression, 56.2% anxiety, and 40.7% stress. Anxiety and stress levels were significantly higher among females compared to males (<i>p</i> < 0.001 and <i>p</i> = 0.005, respectively). In fully adjusted models, depression scores were significantly higher in the highest DII tertile compared to the lowest (B = 1.74; 95% CI: 0.24-3.26), while well-being was lower (B = -0.82; 95% CI: -1.65 to -0.00). For DAI, participants in tertile 2 had significantly lower anxiety (B = -1.38; 95% CI: -2.63 to -0.14), depression (B = -1.69; 95% CI: -3.19 to -0.19), and stress (B = -1.70; 95% CI: -3.22 to -0.18) scores compared to tertile 1. No significant association was found between DAI and well-being. <b>Conclusions:</b> In this study, university students' pro-inflammatory diets were associated with poorer mental health profiles. Enhancing the diet's anti-inflammatory potential may be a promising strategy to support mental health in this population.