Effects Of 12-Week Hydrogen-Rich Water Consumption on Body Composition and Metabolic Biomarkers in Adults with Metabolic Syndrome Stratified by Breath Hydrogen Levels: A Randomized Controlled Trial

Abstract

Metabolic syndrome is a cluster of risk factors that increases the likelihood of cardiovascular disease and type 2 diabetes. Hydrogen-rich water (HRW) has been proposed as a nutritional strategy to improve metabolic health, although individual differences in endogenous hydrogen production may influence its effectiveness. In this randomized, double-blind, placebo-controlled trial, 40 adults with metabolic syndrome (mean age 51.2 ± 7.9 years; 27 women) were assigned to consume 1,000 mL/day of HRW or placebo for 12 weeks. Baseline breath hydrogen levels stratified participants into low (< 10 ppm) or high (≥ 10 ppm) hydrogen groups. Anthropometric, body composition, and metabolic biomarkers were assessed at baseline and post-intervention, with change in waist circumference as the primary outcome. HRW supplementation led to significant improvements in body weight, BMI, waist circumference, fat mass, fat-free mass, muscle mass, and total body water compared with placebo (P ≤ 0.05), with large effect sizes observed for reductions in waist circumference. Significant improvements were also noted in fasting glucose, lipid profile, apolipoproteins A and B, and high-sensitivity C-reactive protein (P ≤ 0.05). Treatment effects were generally more pronounced in participants with lower baseline breath hydrogen levels. No major adverse events were reported. These findings indicate that HRW supplementation safely improves multiple components of metabolic syndrome, with greater benefits observed in individuals with lower endogenous hydrogen production, supporting its potential role as a personalized adjunctive intervention.