Vitamin C, vitamin E, β-carotene and risk of Parkinson's disease: a systematic review and dose-response meta-analysis of observational studies

Objective: This study aimed to explore the relationship between the intake of vitamin C, vitamin E and beta-carotene, and the risk of Parkinson's disease (PD). Methods: Web of Science, Embase, PubMed, Cochrane library, CNKI, and WanFang databases were searched from inception to 29 August 2022 for observational studies reporting the odds ratios (ORs) or relative risks (RRs) or hazard ratios (HRs) and 95% confidence intervals (CIs) of PD by Vitamin C/Vitamin E/beta-carotene intake. Random-effects models, publication bias assessment, subgroup, sensitivity and dose-response analyses were performed, using.Stata version 12.0. Results: A total of 13 studies were included. There was no significant association between high-dose vitamin C intake and the risk of PD compared with low-dose vitamin C intake (RR = 0.98, 95%CI:0.89,1.08). Compared with low-dose intake, high-dose intake of vitamin E can prevent the risk of PD (RR = 0.87, 95%CI:0.77,0.99). Compared with lower beta-carotene intake, there was a borderline non-significant correlation between higher intake and PD risk (RR = 0.91, 95% CI:0.82,1.01), and high dose beta-carotene intake was found to be associated with a lower risk of PD in women (RR = 0.78, 95%CI:0.64,0.96). Conclusion: This study shows that vitamin E intake can reduce the risk of PD and play a preventive role.