Peripheral endothelial function can be improved by daily consumption of water containing over 7 ppm of dissolved hydrogen: A randomized controlled trial.

Abstract

This randomized controlled trial enrolled 68 healthy volunteers assigned equally to either a high-concentration hydrogen water group (7 ppm H2; 3.5 mg per 500 mL) or a nitrogen-water placebo group. Peripheral vascular endothelial function was assessed using the reactive hyperemia index (Ln_RHI) measured by peripheral arterial tonometry (PAT) at baseline, 1 hour, 24 hours after the first intake, and following 14 days of daily consumption. The hydrogen water group demonstrated a statistically significant 22.2% increase in Ln_RHI at 24 hours post-ingestion and a 25.4% increase after two weeks of daily intake, both significantly greater than placebo. These findings indicate that sustained consumption of high-concentration hydrogen water is associated with measurable improvements in small artery and arteriole endothelial function, with potential implications for cardiovascular health.

Mechanism

Consumption of hydrogen-rich water at concentrations exceeding 7 ppm was associated with enhanced endothelial responsiveness in peripheral small arteries and arterioles, as reflected by increased Ln_RHI values. The mechanism is presumed to involve reduction of oxidative stress, thereby improving endothelial vasodilatory capacity.