Effects of hydrogen-rich water prepared by alternating-current-electrolysis on antioxidant activity, DNA oxidative injuries, and diabetes-related markers
Asada R, Tazawa K, Sato S, Miwa N. · Medical Gas Research. 2020;10(3):114–121.
Study at a glance
Human
Japanese adults with fasting blood glucose above 6.1 mmol/L and below approximately 7.8 mmol/L who were not taking glucose-lowering medication.
Participants drank 1,500 mL/day of freshly prepared AC-electrolyzed H₂-rich water for eight weeks. · Dissolved H₂ reached 1.55 mg/L after 30 minutes of AC electrolysis; the same preparation had pH 7.7–7.8, dissolved O₂ 14.6 mg/L and ORP −270 mV.
Eight weeks, with measurements at baseline, four weeks and eight weeks.
Urinary 8-OHdG decreased at eight weeks (P=0.028) and fructosamine at four weeks (P=0.008). The 8-OHdG formation-rate change, 1,5-AG changes and eight-week HbA1c change were not statistically significant. The article calls the fasting-glucose change significant while reporting P=0.051, which is above the conventional P<0.05 threshold. No treatment-related abnormality was reported among completers.
Very small uncontrolled open-label study, one dropout, selected borderline-hyperglycemic participants, multiple outcomes and no control for diet, exercise or regression to the mean. The apparatus used a patented commercial method. A Japanese anti-aging research grant partly funded the study; authors declared no conflicts.
What kind of evidence is this?
Human
Open-label single-arm clinical study accompanied by laboratory characterization of the prepared water
Metabolic and lipid health
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
Japanese adults with fasting blood glucose above 6.1 mmol/L and below approximately 7.8 mmol/L who were not taking glucose-lowering medication.
Ten enrolled; one withdrew for clinical reasons and nine completed (five men, four women; age 39–63 years).
Eight weeks, with measurements at baseline, four weeks and eight weeks.
Participants drank 1,500 mL/day of freshly prepared AC-electrolyzed H₂-rich water for eight weeks.
H₂ dissolved in drinking water — not Brown's gas and not inhalation.
Dissolved H₂ reached 1.55 mg/L after 30 minutes of AC electrolysis; the same preparation had pH 7.7–7.8, dissolved O₂ 14.6 mg/L and ORP −270 mV.
Baseline values in the same participants; there was no randomized, blinded or concurrent control group.
Outcomes and reported result
Urinary 8-OHdG measures, fasting glucose, HbA1c, fructosamine, 1,5-anhydro-D-glucitol, routine blood/urine tests and adverse findings.
Urinary 8-OHdG decreased at eight weeks (P=0.028) and fructosamine at four weeks (P=0.008). The 8-OHdG formation-rate change, 1,5-AG changes and eight-week HbA1c change were not statistically significant. The article calls the fasting-glucose change significant while reporting P=0.051, which is above the conventional P<0.05 threshold. No treatment-related abnormality was reported among completers.
The complete free PMC article, methods, figures and disclosure section were checked for water preparation/concentration, participant flow, time points, positive and null findings, the internally problematic P=0.051 wording, safety, funding and conflicts.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Very small uncontrolled open-label study, one dropout, selected borderline-hyperglycemic participants, multiple outcomes and no control for diet, exercise or regression to the mean. The apparatus used a patented commercial method. A Japanese anti-aging research grant partly funded the study; authors declared no conflicts.
Exploratory biomarker observations in nine adults; it does not establish prevention or treatment of diabetes.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 33004708 · DOI: 10.4103/2045-9912.296041
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
10 August 2026
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