Molecular Hydrogen as an Emerging Therapeutic Medical Gas for Neurodegenerative and Other Diseases

Abstract

Effects of molecular hydrogen on various diseases have been documented for 63 disease models and human diseases in the past four and a half years. Most studies have been performed on rodents including two models of Parkinson’s disease and three models of Alzheimer’s disease. Prominent effects are observed especially in oxidative stress-mediated diseases including neonatal cerebral hypoxia; Parkinson’s disease; ischemia/reperfusion of spinal cord, heart, lung, liver, kidney, and intestine; transplantation of lung, heart, kidney, and intestine. Six human diseases have been studied to date: diabetes mellitus type 2, metabolic syndrome, hemodialysis, inflammatory and mitochondrial myopathies, brain stem infarction, and radiation-induced adverse effects. Two enigmas, however, remain to be solved. First, no dose-response effect is observed. Rodents and humans are able to take a small amount of hydrogen by drinking hydrogen-rich water, but marked effects are observed. Second, intestinal bacteria in humans and rodents produce a large amount of hydrogen, but an addition of a small amount of hydrogen exhibits marked effects. Further studies are required to elucidate molecular bases of prominent hydrogen effects and to determine the optimal frequency, amount, and method of hydrogen administration for each human disease.

Study details

Article type

Review

Disease / injury model

Multiple disease models including Parkinson's disease, Alzheimer's disease, ischemia/reperfusion injury, diabetes, metabolic syndrome, and others.

Dose comparison

The review discusses the lack of a dose-response effect, noting that both low and high doses of hydrogen can be effective, and that hydrogen-rich water can be as effective as inhalation, despite much lower total hydrogen exposure.

Dose-dependent effect

No

Outcome

Positive

Findings

Molecular hydrogen has shown beneficial effects in 63 disease models and human diseases, especially those mediated by oxidative stress, including neurodegenerative diseases, ischemia/reperfusion injuries, and metabolic disorders. Notably, no adverse effects have been reported, and hydrogen appears effective even at low doses, though no clear dose-response relationship is observed.