Hydrogenology editorial study record

Hydrogen-rich water for improvements of mood, anxiety, and autonomic nerve function in daily life

Mizuno K et al. · Med Gas Res. 2017;7(4):247–255.

HumanH₂-rich waterPublished 2017

Study record, not medical adviceThis page reports one source and Hydrogenology’s source-text extraction. It does not establish that molecular hydrogen is effective, safe or appropriate for any person. Human, animal and laboratory evidence must not be treated as equivalent.

Source and classification

What kind of evidence is this?

Evidence stream

Human

Reported design

Randomized double-blind placebo-controlled two-period crossover study

Research topic

Sleep and mood research

Administration classification

H₂-rich water

Study result signal

Not reported in this record.

Outcome type

Not reported in this record.

Reported in the source

Methods at a glance

Population or model

Healthy adult volunteers aged 20–49 years

Sample

31 randomized; 26 analyzed

Duration

4 weeks per condition with a 4-week washout

Intervention

Hydrogen-rich water, 300 mL twice daily

Hydrogen form

H₂ dissolved in water — H₂ only, not Brown’s gas.

H₂ specification

0.8–1.2 ppm dissolved H₂ in 300 mL aluminum pouches.

H₂ flow

Not applicable — oral water, not gas inhalation.

O₂ delivered with H₂

No O₂ was co-delivered as part of the intervention.

Comparator

Identically packaged placebo mineral water without H₂

Reported, not endorsed

Outcomes and reported result

Outcomes measured

Fatigue, mood, anxiety, depression, sleep questionnaires, autonomic measures, cognitive testing and blood markers

Reported result

Change ratios for K6 mood/anxiety score and resting sympathetic activity were lower after H₂ water. Many other questionnaire and biological outcomes did not show clear between-condition differences.

Results-extraction completeness

Dose, methods, main results, registration, funding and conflicts checked in the free full text; independent appraisal remains incomplete.

A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.

Interpretation limits

Cautions and applicability

Design and reporting cautions

Small healthy-volunteer crossover study, five exclusions from analysis, many outcomes and subjective scales. The corresponding author received funding from the water supplier Melodian Corporation.

Applies directly to

Healthy adults under the reported four-week drinking protocol; not people with a diagnosed mood or sleep disorder.

Preliminary appraisal framework

Not reported in this record.

Preliminary risk-of-bias status

Not reported in this record.

Appraisal rationale

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.

Provenance

Sources and record status

Identifiers

PMID: 29497485 · DOI: 10.4103/2045-9912.222448

Publisher access

Open-access full text is available through PMC.

Extraction basis

Open-access PMC full text and PubMed bibliographic record.

Record revision

2026-08-10

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