The paper's author Marc Lemaire is from Air Liquide international's Saclay Research Centre in Paris.

Lemaire M ,  Barbier F . Hydrogen: therapeutic potential in wellness and medicine.  2017.

Persistent oxidative stress plays an important role in a variety of pathological processes, and the search for effective and well-tolerated antioxidants continues.  Molecular hydrogen, as a therapeutic antioxidant, can selectively reduce cytotoxic oxygen radicals.  The nonspecific mechanism of hydrogen as a therapeutic antioxidant makes it potentially useful in a wide range of medical applications, as demonstrated by extensive preclinical data and increasing clinical evidence.

This review summarized the disease treatment and health promotion potential of hydrogen, in the fight against aging and maintain healthy and disease treatment, etc., including acute ischemia/reperfusion injury, inflammation and ulcers, metabolic disorders and neurodegenerative diseases and cancer, anticancer, radiation toxicity and the side effects of cisplatin), focuses on the clinical data.  In summary, hydrogen is a potent antioxidant, anti-inflammatory, and cell protector.

Hydrogen, made up of one proton and one electron, is the lightest and most abundant element in the universe.  On Earth, hydrogen does not normally exist on its own, but as a compound with other elements.  The most common sources of hydrogen are hydrocarbons, water, and carbohydrates from which molecular hydrogen can be produced.  More than 50 million tons of hydrogen are produced worldwide each year, making it one of the oldest molecules known to be widely used in many industrial fields.

Most uses of hydrogen are based on its physical properties, such as its very low molecular weight (2.0159 g/mol H2) and very low density (0.084 g/ L at 20°C and 1 ATM), as well as its reductive chemical properties, hydrogen has the potential to be an important energy solution in the future because of its high calorific value and environmentally friendly properties.  When used in fuel cells to generate electricity, only water is produced.

The role and application of molecular hydrogen in medicine has been discovered by accident only in the last decade or so, and many questions remain to be fully clarified. Hydrogen is believed by many to have biodamage-resistant properties and is an essential antioxidant for all cells. The production of reactive oxygen species (ROS) by-products is also associated with oxidative phosphorylation of energy metabolism in aerobic organisms such as humans. Overproduction or endogenous antioxidant capacity ROS damage can lead to accumulation of ROS, it is generally believed that sustained oxidative stress plays an important role in a variety of pathology, including lifestyle related diseases, such as atherosclerosis and diabetes, high blood pressure, chronic inflammation, neurodegenerative diseases, cancer, blood vessel function decline and the aging process. However, prospective controlled clinical trials of antioxidant therapy for the prevention of oxidative stress-related diseases, mainly cardiovascular disease, have failed in the past. Therefore, the search for an effective and well-tolerated antioxidant continues.

Hydrogen is an odorless, tasteless gas that has an ideal effect on oxidative stress in almost all organs. Molecular hydrogen, as a therapeutic antioxidant, plays a therapeutic role by selectively reducing cytotoxic oxygen free radicals. Hydrogen has some properties that suggest it may be one of the most ideal antioxidants for human use. These characteristics include the ability to neutralize hydroxyl radicals (•OH) within living cells such as across the blood-brain barrier, as well as stability and low water solubility (1.9 PPM) at room temperature and good biological tolerance. Table 2 summarizes the superior physical and chemical properties of hydrogen and its therapeutic benefits. Thus, hydrogen may have potential uses in many human diseases known to be associated with oxidative stress, and may play an important role in the prevention of aging and in many healthcare applications.

In addition to its role as an antioxidant, there is evidence that the hydrogen molecule also has anti-inflammatory properties by neutralizing hydroxyl radicals produced during inflammation. There is also evidence that hydrogen acts directly on inflammation by regulating signal transduction in macrophages and by inhibiting lipopolysaccharide/interferon γ -induced nitric oxide production. Thus, hydrogen may also have a therapeutic role in many inflammatory human diseases.

In addition, hydrogen has also been shown to prevent apoptosis, probably also by its ability to reduce or eliminate hydroxyl radicals (•OH) and peroxynitrite (ONOO-). Importantly, a variety of hydrogen use methods have been established, including inhaling the gas, drinking hydrogen injections, eye drops, dialysis, or hydrogen baths.