Liver Hydrolysate Preserves Muscle Mass and Potentially Attenuates Exercise-induced Oxidative Stress in Humans-A Randomized, Double-blind, Placebo-controlled Study-

Background　Liver hydrolysate（LH）is obtained via an enzymatic degradation of livers. LH has an anti-fatigue effect. However, it remained unclear whether LH affected muscle mass and exercise-induced oxidative stress in humans. The purpose of this study was to investigate the effects of LH on body composition and exercise -induced oxidative stress in humans. Methods　A randomized, double-blind, placebo-controlled study was designed to investigate the effect of LH in Japanese women and men aged 19-21 years. Participants included 16 Japanese subjects recruited from visitors to Chubu University, where the 4-week study was conducted. Participants were randomly assigned to receive either 0 mg/day LH （placebo group）or 600 mg/day LH（LH group）by a controller. We evaluated the efficacy of LH in humans by measuring changes in body composition, maximal oxygen uptake（V4O2max）, levels of reactive oxidative metabolites（d-ROMs）, and biological antioxidant power（BAP）levels during rest and exercise. Results　After 4 weeks, the change in muscle mass was significantly higher in the LH group than in the placebo group. The change in body fat was significantly lower in the LH group than in the placebo group. V4O2max values did not differ between the two groups. d-ROM levels in the rest and end tests were significantly lower in the LH group than in the placebo group. BAP levels did not differ significantly between the groups in the rest and end tests. We calculated changes in d-ROM response to the incremental exercise test from pre- to post-supplementation, i.e., a negative value indicated d-ROM levels decreased after 4 weeks of LH supplementation. The change tended to be lower in the LH group compared to the placebo group. Conclusion　LH may be a useful method for improving human exercise performance. （UMIN 000034290）