Dietary quality and the odds of parkinson’s disease: insights from comprehensive diet quality index and adjusted plant-based diet index

This study evaluated the link between two dietary indicators— the Comprehensive Diet Quality Index (CDQI) and the Adjusted Plant-Based Diet Index (APDI)—and Parkinson’s disease (PD) risk in an Iranian community. Between 2020 and 2021, 105 newly diagnosed PD patients and 215 controls (54–81 years) were enrolled in Arak, Iran, using a case-control approach. A validated semi-quantitative food frequency questionnaire was applied to determine dietary intake, and dietary quality was evaluated through APDI and CDQI scores. To calculate odds ratios (ORs) and 95% confidence intervals (CIs), logistic regression models were utilized, accounting for possible confounders. A higher CDQI total score was inversely related to the odds of PD (adjusted OR = 0.915, 95% CI: 0.878–0.954). A stronger protective effect was observed for the CDQI plant-based foods score (adjusted OR = 0.757, 95% CI: 0.695–0.824). In contrast, a notable positive relationship was found between the CDQI animal-based foods score and the odds of PD in the adjusted model (adjusted OR = 1.364, 95% CI: 1.215–1.533). The APDI score and PD were not significantly correlated (P > 0.05).