In 2007 "Nature Medicine", the famous medical journal, published article "Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals" where was said that molecular hydrogen has therapeutic effect on human body.
It removes harmful free radicals from the body by converting them into the regular water. Hydrogen readily gives up electrons to hydroxyl radicals, which stabilizes them and stops them in their tracks. It also reduces the toxicity of peroxynitrite, another destructive oxidant, and further boosts the body's defenses by increasing production of natural antioxidants such as glutathione, superoxide dismutase, and catalase.
SECOND, H2 has beneficial effects on cell signaling and gene expression. It suppresses TNF-alpha and other proteins involved in inflammation and turns on mechanisms that protects against cell death. But because Hydrogen is selective, it does not scavenge essential redox signaling radicals that play a key role as cellular messengers.THIRD, recent studies show that hydrogen water increases the production of a hormone called ghrelin. Secreted in the stomach, ghrelin is best known for stimulating appetite, but it also boosts growth hormone release and has protective effects in the brain, vascular system, liver, and elsewhere.
FORTH, Hydrogen “nano” molecules are able to diffuse through cellular membranes, enter the mitochondria and nucleus of cells, cross the blood-brain barrier, and exert their positive effects in tissues and organs throughout the body.
Therefore, it’s not surprising that benefits of Hydrogen therapy have been demonstrated in animal models and/or human studies in a wide range of conditions, including traumatic brain and spinal cord injuries, Parkinson's, Alzheimer's, strokes, heart attacks, vascular disease, diabetes, liver and kidney disorders, autoimmune conditions, and lung problems.