Oral hydrogen water prevents chronic allograft nephropathy in rats
Cardinal JS, Zhan J, Wang Y, Sugimoto R, Tsung A, McCurry KR, Billiar TR, Nakao A. · Kidney International. 2010;77(2):101–109.
What kind of evidence is this?
Preclinical
Controlled orthotopic kidney-transplant experiment with syngeneic and allogeneic rat groups
Kidney and urinary health
H₂-rich water
Not reported in this record.
Not reported in this record.
Methods at a glance
Male Lewis donor kidneys transplanted into Lewis syngeneic or bilaterally nephrectomized Brown Norway allogeneic recipients; allograft recipients received short-course tacrolimus.
Initial groups were isograft plus regular water n=8, isograft plus H₂ water n=8, allograft plus regular water n=18 and allograft plus H₂ water n=17. Survival analyses used n=5, n=5, n=13 and n=12 respectively; other assays used smaller stated subsets.
From transplantation through day 60 tissue/function assessments or survival follow-up to death or day 150.
From transplantation day 0, recipients drank hydrogen-rich water ad libitum; 500 mL batches were placed in glass drinking vessels twice daily. Allograft recipients also received tacrolimus 0.5 mg/kg intramuscularly on days 0–6.
H₂ dissolved in drinking water — H₂ only, not Brown's gas.
Water was produced by dissolving H₂ at 0.4 MPa, stored in aluminum bags and reported above 0.6 mmol/L when supplied to the drinking vessels.
Not applicable — drinking water, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
Transplant recipients drinking degassed regular water, with parallel syngeneic and allogeneic transplant groups.
Outcomes and reported result
Proteinuria, creatinine clearance, body weight, graft failure and survival, histology and fibrosis, inflammatory-cell infiltration, oxidative-damage markers, cytokine/adhesion-molecule expression and MAP-kinase signaling.
Hydrogen-rich water was associated with better allograft function, less chronic allograft injury, oxidative damage, inflammation and MAP-kinase activation, and longer survival: median survival exceeded 150 days versus 78 days with regular water. The study also reports that repeated long-term administration did not produce baseline circulating H₂ accumulation.
The complete open-archive publisher article, transplant and co-treatment protocols, initial and analysis-specific group sizes, water preparation and concentration, functional, survival, histological and molecular results, funding and conflict statement were checked.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Preclinical transplant model with different immunosuppression between syngeneic and allogeneic arms, assay-specific subsets, multiple outcomes and attrition reflected in smaller survival cohorts. Daily water consumption and ingested H₂ dose per rat were not reported. US federal grants and a Hydrogen Research Foundation award funded the study; all authors declared no competing interests.
Rat kidney transplantation with short-course tacrolimus; it does not establish efficacy, safety or dosing in human transplant recipients.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 19907413 · DOI: 10.1038/ki.2009.421
Open-archive complete publisher article.
Complete Kidney International/ScienceDirect open-archive article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10