# Dietary Phytochemicals and Depressive Symptoms in Young Adults: Evidence from Undergraduate Students in Türkiye

## TL;DR

This study found that eating more phytochemical-rich foods, like fruits and vegetables, is linked to fewer depressive symptoms in Turkish undergraduate students.

## Contribution

The study introduces the Dietary Phytochemical Index as a novel tool to assess mental health outcomes in young adults.

## Key findings

- Higher Dietary Phytochemical Index scores were associated with significantly lower depression scores.
- The inverse association remained significant after adjusting for gender, income, and academic department.
- A linear trend in depression scores was observed across increasing Dietary Phytochemical Index quartiles.

## Abstract

Background/Objectives: Depression is a prevalent mental health problem among undergraduate students, and dietary patterns may play a role in its prevention. Phytochemical-rich diets have been proposed to be potential protective factors against depression due to their antioxidant, anti-inflammatory, and neuroprotective properties. This study aimed to investigate the association between the Dietary Phytochemical Index (DPI) and depressive symptoms among undergraduate students in Türkiye. Methods: A descriptive, cross-sectional study was conducted among 789 undergraduate students at Erciyes University between May 2024–May 2025. Dietary data were collected using a 101-item Food Frequency Questionnaire, and the DPI was calculated as the percentage of total daily energy derived from phytochemical-rich foods. Depressive symptoms were assessed via the Burns Depression Checklist (BDC). Statistical analyses included correlation and logistic regression models adjusted for gender, income, and academic department. Results: Participants with higher DPI scores exerted significantly lower BDC total and sub-dimension scores, including activities and personal relationships, physical symptoms, and suicidal urges (all p < 0.05). The inverse association between DPI and total depression score remained significant across all adjusted models (p < 0.001), and a significant linear trend was observed across DPI quartiles (p-trend < 0.001). Conclusions: Higher dietary phytochemical intake was associated with lower depressive symptom levels among undergraduate students. These results suggest that phytochemical-rich dietary patterns, characterized by increased consumption of fruits, vegetables, whole grains, legumes, and nuts, may contribute to improved psychological well-being. Promoting the intake of phytochemical-dense foods could be a practical nutritional strategy for supporting mental health in young adults.