While non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease worldwide, its treatment remains elusive. Since metabolic impairment plays a major role in NAFLD pathogenesis, any pharmaceuticals, such as molecular hydrogen (H₂), that advance lipid and glucose metabolism could be appropriate to tackle this complex condition. The aim of this study was to analyze the effects of 28-day hydrogen-rich water intake on liver fat deposition, body composition and lab chemistry profiles in overweight patients suffering from mild-to-moderate NAFLD.

Twelve overweight outpatients with NAFLD (age 56.2 ± 10.0 years; body mass index 37.7 ± 5.3 kg/m²; 7 women and 5 men) voluntarily participated in this double-blind, placebo-controlled, crossover trial. All patients were allocated to receive either 1 L per day of hydrogen-rich water (HRW) or placebo water for 28 days. The study was registered at ClinicalTrials.gov (ID NCT03625362).

Dual-echo MRI revealed that HRW significantly reduced liver fat accumulation in individual liver regions-of-interest at 28-day follow-up, as compared to placebo administration (P < 0.05). Baseline liver fat content was reduced from 284.0 ± 118.1 mM to 256.5 ± 108.3 mM after hydrogen treatment at 28-day follow-up (percent change 2.9%; 95% CI from 0.5 to 5.5). Serum aspartate transaminase levels dropped by 10.0% (95% CI; from −23.2 to 3.4) after hydrogen treatment at 28-day follow-up. No significant differences were observed between treatment groups in either weight or body composition among participants.

Although preliminary, the results of this trial perhaps nominate HRW as an adjuvant treatment for mild-to-moderate NAFLD. These observations provide a rationale for further clinical trials to establish safety and efficacy of molecular hydrogen in NAFLD.