Randomized, double‐blind, multicenter trial of hydrogen water for Parkinson's disease

Oxidative stress might be involved in Parkinson’s disease (PD) progression. Molecular hydrogen (H2) water has been shown to reduce oxidative stress and dopaminergic neuronal cell loss in a PD model. A previous randomized, doubleblind study showed that drinking 1,000 mL of H2 water per day for 48 weeks significantly improved the total Unified Parkinson’s Disease Rating Scale (UPDRS) scores of patients with PD and treated with levodopa. We conducted a longer and larger scale H2 water trial that also included patients who were not treated with levodopa. A placebo-controlled, randomized, double-blind, parallel-group (1:1) clinical trial was performed in 14 hospitals (trial registration UMIN000010014). The inclusion criteria, ethical considerations, randomization, blinding, procedures, statistical analyses, and characteristics of the 178 enrolled Japanese participants with PD (93 women and 85 men; an error in this number exists in the previous report) were described previously. At the baseline visit, the groups were well matched (Supplementary Table 1). The reasons for discontinuation of the study were disease progression, adverse events, unwillingness to proceed, and failure to comply with the protocol (Supplementary Table 2 and Supplementary Figure 1). There were no significant differences in the change in the total UPDRS score from baseline to the 72nd week between the H2-water group (1.6 ± 14.0 [mean ± standard deviation]) and the placebo water group (0.8 ± 9.6; t test, P = .939; analysis of variance, P = .538; Table 1). There were no significant differences in changes in the scores on parts II and III of the UPDRS, the individual parts of the UPDRS, the Hoehn and Yahr stage, and the Parkinson’s Disease Questionnaire-39 *Corresponding author: Dr. Asako Yoritaka, Department of Neurology, Juntendo University Koshigaya Hospital. Fukuroyama 560, Koshigayashi, Saitama, Japan, 343-0032; ayori@juntendo.ac.jp