Breath hydrogen produced by ingestion of commercial hydrogen water and milk.
Shimouchi A, Nose K, Yamaguchi M, Ishiguro H, Kondo T. · 2009.
What kind of evidence is this?
Human
Small uncontrolled pharmacokinetic comparison
Other molecular hydrogen research
H₂-rich water
Acute dose-related breath-hydrogen signal.
Human pharmacokinetic surrogate outcome.
Methods at a glance
Five adults without specified disease.
5 participants.
Acute breath-hydrogen monitoring after ingestion.
Ingestion of commercial hydrogen water, distilled water and milk on separate test conditions.
H₂ dissolved in drinking water.
Dose-response water volumes are reported in the article; breath exposure was measured rather than systemic dose.
Not applicable.
No oxygen was co-delivered.
Distilled water and milk reference conditions.
Outcomes and reported result
End-alveolar breath-hydrogen concentration and time course.
Hydrogen water produced a rapid, dose-related breath-hydrogen peak around 10–15 minutes that returned toward baseline sooner than after milk.
The full article was checked for methods, intervention details, outcomes, positive and null findings, funding and conflicts. This record does not imply medical efficacy.
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
Five-person pharmacokinetic experiment with no health outcome; breath hydrogen does not establish therapeutic efficacy.
Healthy adults under this acute ingestion test only.
ROBINS-I — preliminary
Serious concerns
Very small uncontrolled experiment, unclear order effects and a surrogate exposure measure only.
Selection and allocation checked · Confounding and co-interventions remain possible · Missing observations checked where reported · Outcome measurement varies by endpoint · Selective reporting cannot be excluded
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: 19652760 · DOI: 10.4137/bmi.s2209
A free full article is available through PubMed Central.
Official PubMed Central full article and PubMed bibliographic record; source identity, methods, intervention, results, funding and conflicts checked 10 August 2026.
2026-08-10