Consumption of water containing a high concentration of molecular hydrogen reduces oxidative stress and disease activity in patients with rheumatoid arthritis: an open-label pilot study
Ishibashi T et al. · Med Gas Res. 2012;2(1):27.
Study at a glance
Human
Adults with rheumatoid arthritis continuing their usual therapy
530 mL/day high-H₂ water for 4 weeks, followed by 4 weeks without it, then another 4-week treatment period · 4–5 ppm dissolved H₂ at preparation, described as supersaturated water.
Two 4-week treatment periods separated by a 4-week washout
8-OHdG and DAS28 decreased during treatment, but mean DAS28 also continued to decrease during the washout period. The report emphasizes a five-person early-RA subgroup.
Open-label, uncontrolled 20-person pilot; ongoing usual therapy, regression to the mean and the continued improvement during washout make causal attribution uncertain. The five-person subgroup is especially fragile.
What kind of evidence is this?
Human
Open-label uncontrolled pilot with two treatment periods
Immune and inflammatory conditions
H₂-rich water
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Adults with rheumatoid arthritis continuing their usual therapy
20 participants
Two 4-week treatment periods separated by a 4-week washout
530 mL/day high-H₂ water for 4 weeks, followed by 4 weeks without it, then another 4-week treatment period
H₂ dissolved in water — H₂ only, not Brown’s gas.
4–5 ppm dissolved H₂ at preparation, described as supersaturated water.
No placebo or concurrent untreated comparator
Outcomes and reported result
Urinary 8-OHdG and rheumatoid-arthritis disease activity score DAS28-CRP
8-OHdG and DAS28 decreased during treatment, but mean DAS28 also continued to decrease during the washout period. The report emphasizes a five-person early-RA subgroup.
Methods and main results checked in the free full text; independent appraisal and complete commercial-support extraction remain incomplete.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Open-label, uncontrolled 20-person pilot; ongoing usual therapy, regression to the mean and the continued improvement during washout make causal attribution uncertain. The five-person subgroup is especially fragile.
Adults with rheumatoid arthritis under continued background care in this pilot.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 23031079 · DOI: 10.1186/2045-9912-2-27
Open-access article.
Free full text on PMC; identifiers cross-checked in PubMed.
10 August 2026
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