Health Effects of Electrolyzed Hydrogen Water for the Metabolic Syndrome and Pre-Metabolic Syndrome: A 3-Month Randomized Controlled Trial and Subsequent Analyses
Moribe R, Minami M, Hirota R, et al. · Antioxidants. 2024;13(2):145.
What kind of evidence is this?
Human
Randomized double-blind filtered-water-controlled parallel trial with subsequent subgroup analyses
Metabolic and lipid health
H₂-rich water
Not reported in this record.
Not reported in this record.
Methods at a glance
Adults aged at least 30 years in Susaki City with metabolic syndrome or pre-metabolic syndrome.
200 randomized; 181 analyzed: EHW n=91 and filtered water n=90.
3 months.
Participants drank 350 mL of freshly produced electrolyzed hydrogen water morning, afternoon and evening (1,050 mL/day) from an installed TRIM ION HYPER device.
H₂ dissolved in electrolyzed drinking water — H₂ only as the therapeutic gas, not Brown's gas.
The article does not report a numeric dissolved-H₂ concentration or measurements at drinking time.
Not applicable — drinking water, not gas inhalation.
No O₂ was co-delivered as an intervention.
Filtered water produced by outwardly identical devices installed at participants' homes.
Outcomes and reported result
Primary change in waist circumference; body composition, blood pressure, glucose, lipids, inflammatory and oxidative-stress markers, physical-activity subgroups and adverse events.
The prespecified overall analysis was null for waist circumference (-1.27 versus -1.05 cm; p=0.65) and every reported secondary endpoint. A post hoc high-physical-activity subgroup (15 versus 12 participants) favored EHW for waist change; other subgroup findings were inconsistent. No adverse events were observed.
The complete MDPI and PMC articles, participant flow, primary and secondary tables, subgroup analyses, adverse events and company participation were checked; all null overall outcomes are represented.
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
The randomized overall analysis was entirely null. Groups differed at baseline in waist circumference, total cholesterol and triglycerides; 19 randomized participants were excluded; many small post hoc subgroups were tested. The study was a joint project of Susaki City, Kochi University and manufacturer Nihon Trim, which supplied, allocated and installed the devices; one author had a company affiliation.
Adults with metabolic or pre-metabolic syndrome matching this Japanese municipal cohort; the subgroup findings do not establish an overall treatment effect.
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: 38397743 · DOI: 10.3390/antiox13020145
Open-access full articles on MDPI and PMC.
MDPI publisher and PMC full articles plus PubMed record; full-text and article-status check completed 8 August 2026.
2026-08-10