# Effects of concomitant use of hydrogen water and photobiomodulation on Parkinson disease: A pilot study.
> 水素水と光生体調節の併用がパーキンソン病に与える影響：パイロット研究


## Abstract

This pilot study enrolled 18 Parkinson disease (PD) patients at Hoehn and Yahr stages II–III (age range 30–80 years) to evaluate the safety and efficacy of a 2-week daily regimen combining photobiomodulation (PBM) with hydrogen-rich water (H2). The rationale was that PBM enhances mitochondrial function and ATP synthesis but may elevate reactive oxygen species (ROS), while H2 acts as a selective antioxidant capable of neutralizing excess ROS. Unified Parkinson Disease Rating Scale (UPDRS) scores declined significantly within the first week and the improvement persisted through the end of the intervention period. One week after cessation, scores showed a slight rebound yet remained significantly better than baseline. No adverse events were recorded, supporting the safety profile of this combined approach. The authors conclude that a larger randomized trial is needed to confirm these preliminary findings.

### Mechanism

PBM is proposed to upregulate mitochondrial function and ATP production, but concurrently elevates ROS levels; H2 selectively scavenges these excess ROS, thereby providing neuroprotection in dopaminergic pathways relevant to PD.

## Bibliographic

- **Authors**: Hong CT, Hu CJ, Lin HY, Wu D
- **Journal**: Medicine (Baltimore)
- **Year**: 2021 (2021-01-29)
- **PMID**: [33530211](https://pubmed.ncbi.nlm.nih.gov/33530211/)
- **DOI**: [10.1097/MD.0000000000024191](https://doi.org/10.1097/MD.0000000000024191)
- **PMC**: [PMC7850666](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7850666/)
- **Study type**: human case report
- **Delivery route**: mixed routes
- **Effect reported**: positive

## Delivery context

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 33530211. https://h2-papers.org/en/papers/33530211
> **Source**: PubMed PMID [33530211](https://pubmed.ncbi.nlm.nih.gov/33530211/)