Background: Several dietary components have been shown to be neuroprotective against risk of neurodegeneration. However, limited observational studies have examined the role of overall diet quality on risk of Parkinson's disease.
Objectives: We examined the associations between diet quality and risk of Parkinson's disease in a prospective cohort study and meta-analysis.
Methods: Included in the cohort study were 3,653 participants (1,519 men and 2,134 women; mean age: 81.5 years) in the Geisinger Rural Aging Study longitudinal cohort in Pennsylvania. Diet quality was assessed using a validated dietary screening tool containing 25 food- and behavior-specific questions in 2009. Potential Parkinson's cases were identified using electronic health records based on ICD9 (332.*), ICD10 (G20), and Parkinson-related treatments. Hazard ratios (HRs) and 95% confidence intervals (CIs) across diet quality tertiles were calculated using Cox proportional hazards models after adjusting for potential confounders. We further performed a meta-analysis by pooling our study with four published papers on this topic. Random-effects model was utilized to calculate the pooled risk ratios and 95% CIs.
Results: During a mean of 6.94 years of follow-up, 47 incident Parkinson's cases were documented. Having high diet quality at baseline was associated with lower Parkinson's disease risk (adjusted HR for the highest vs the lowest diet quality tertile = 0.39; 95% CI: 0.17, 0.89; p-trend = 0.02). The meta-analysis including 140,617 individuals also showed that adherence to high diet quality or a healthy dietary pattern was associated with lower risk of Parkinson's disease (pooled risk ratio = 0.64; 95% CI: 0.49, 0.83).
Conclusion: Having high diet quality or a healthy dietary pattern was associated with lower future risk of Parkinson's disease.
Keywords: Diet quality; Parkinson’s disease; meta-analysis; prospective study.