How Hydrogen Works in the Body May Not Be What Scientists Thought
- Authors
- Qinjian Li, Fei Xie, Yang Yi, Pengxiang Zhao, Xin Zhang, Xiaokang Zhang, Xujuan Zhang, Xuemei Ma
- Journal
- BioRxiv
- Year
- 2021
- DOI
- 10.1101/2021.03.13.435216
- Study Type
- Molecular Assay
- Outcome
- Neutral
- Peer Reviewed
- Yes
- Country
- China
- Health Condition
- Oxidative Stress
- Body System
- Cellular
TL;DR
Hydrogen's health benefits are not solely due to its ability to neutralize harmful molecules, but rather its complex interactions with enzymes and other large molecules in the body.
Key Finding
Hydrogen reacts with hydroxyl radicals too slowly to account for its observed biological effects, suggesting its benefits come from other mechanisms such as direct interaction with enzymes.
Summary
Researchers tested whether hydrogen water works by neutralizing harmful molecules called hydroxyl radicals, as previously suggested. Using lab experiments, they found that hydrogen reacts with these radicals too slowly to explain hydrogen's documented health benefits in animals and humans. Instead, they discovered that hydrogen can directly boost the activity of certain enzymes, suggesting it may work through different biological pathways than originally thought.
Practical Takeaway
This laboratory study challenges the leading explanation for how hydrogen water might work in the body, but it does not test hydrogen's actual effects in living systems. The findings suggest researchers need to investigate alternative mechanisms, but more research—including human studies—is needed to understand how hydrogen might benefit health.
Abstract
Since Ohsawa et al. reported a biological antioxidant function of hydrogen in 2007, researchers have now shown it to exert protective effects in a wide range of human and animal disease models. Clinical observations and scientific arguments suggest that a selective scavenging property of H2 cannot adequately explain the beneficial effects of hydrogen. However, there is no experiment challenging the original published data, which suggested that molecular hydrogen dissolved in solution reacts with hydroxyl radicals in cell-free systems. Here we report that a hydrogen-saturated solution (0.6 mM) did not significantly reduce hydroxyl radicals in the Fenton system using 1 mM H2O2. We replicated the same condition as Ohsawa’s study (i.e. 5 μM H2O2), and observed a decrease in •OH radicals in both the H2-rich and N2-rich solutions, which may be caused by a decreased dissolved oxygen concentration. Finally, we determined the effect of hydrogen on a high-valence iron enzyme, horseradish peroxidase (HRP), and found that hydrogen could directly increase HRP activity in a dose-dependent manner. Overall, these results indicate that although H2 and •OH can react, the reaction rate is too low to have physiological function. The target of hydrogen is more complex, and its interaction with enzymes or other macro-molecules deserve more attention and in-depth study.