Diet Quality is Associated with Prodromal Parkinson's Disease Features in Chinese Adults

Background: The prodromal phase of Parkinson's disease (PD) is a critical window for prevention by modifying lifestyle factors. However, there is limited knowledge on how diet quality is associated with prodromal PD symptoms in Asian populations. Objective: To examine the association between overall diet quality and prodromal PD features. Methods: A total of 71,640 Chinese participants who were free of PD were included in this cross-sectional study. Diet quality was assessed using the modified Alternative Healthy Eating Index (mAHEI) and alternate Mediterranean Diet (aMED). Five prodromal features including probable rapid eye movement sleep behavior disorder (pRBD), hyposmia, excessive daytime sleepiness, constipation, and depressive symptom were measured using validated questionnaires. Logistic regression was used to calculate the odds ratio (OR) for having a combination of prodromal PD symptoms (1 and 2+ symptoms vs. 0 symptoms), adjusting for age, sex, lifestyle factors, total energy intake, and other potential confounders. Results: In the multivariable-adjusted model, the OR for having 2+ versus 0 prodromal PD features was 0.64 (95% confidence interval [CI]: 0.49, 0.85) comparing the highest versus the lowest mAHEI diet quality quartiles with a significant inverse trend (P-trend = 0.003). For individual prodromal PD features, better diet quality, as assessed by the mAHEI, was associated with lower odds of having excessive daytime sleepiness and constipation (P-trend < 0.05 for both). We observed a marginally significant association between aMED and prodromal PD features (adjusted OR comparing the extreme quartiles = 0.74; 95% CI: 0.55, 0.98; P-trend = 0.09). Conclusion: Better diet quality, as assessed by the mAHEI and the aMED, was associated with lower probability of having prodromal PD features in Chinese adults.