We evaluated the properties and real existence of an electrolyzed-reduced water, which we prepared, and three commercially purchased water goods, that are advertised to have antioxidant activities by the action of ‘active hydrogen,’ on the basis of the results of examinations for inhibitory effects on the oxidative reactions of biomolecules, quantitative analyses of the minerals, and the ESR spectral data in measurement of the scavenging ability for reactive oxygen species. The results suggested that all of the examined aqueous solution systems undoubtedly have antioxidant activities in vitro and that such effects are derived from ordinary molecular hydrogen (hydrogen gas) and/or (a) reductive vanadium ion(s). ‘Active hydrogen’ seems to be absent as an effective component of the antioxidant activities of these aqueous solution systems.
The in vivo effects of drinking a water product, which had been confirmed to have antioxidant activi- ties in vitro, were preliminarily studied by monitoring the blood concentrations of oxidative stress marker substances in the two group subjects who ingested the same quantity of the water product and a tap water solution during the same time. The results indicated that hydrogen gas and reductive vanadium ions as the components responsible for the antioxidant activities in vitro cannot enhance the scavenging ability for re- active oxygen species in vivo after being drunk and absorbed into the human body, although it was sug- gested that an ingestion of a greater quantity of water than usual gives a slight reduction, overall, in the oxi- dative stress.