The sustainable development goals(SDG) of the UNO would be difficult to achieve without prevention of metabolic diseases and other non-communicable diseases (NCDs). Western diet and lifestyle, which are major risk factors of NCDs, are known to cause oxidative stress and decrease in production of molecular hydrogen in the intestines which leads to a decline in endogenous antioxidant status in the body, leading to increase in systemic inflammation. Many experts consider molecular hydrogen as a potential nutrient, which may be administered as gas in the body. There are gaps in the knowledge about the role molecular hydrogen plays, in the treatment of metabolic diseases and other NCDs This review aims to discuss the role of hydrogen in the pathogenesis and prevention of NCDs. Molecular hydrogen (H2) has been studied extensively as a therapeutic gas, with an estimated 2000 publications to date, exploring its potential therapeutic use in 170 disease models across every organ in the mammalian body. Hydrogen therapy can be administered through several methods, such as H2 inhalation, dissolving H2 gas in water to make hydrogen-rich water (HRW) for oral consumption or topical application, or hydrogen-rich saline. The exact mechanism of action of molecular hydrogen is not known but it is in itself a potential antioxidant that can also inhibit hydroxyl and nitrosyl radicals in the cells and tissues. Hydrogen is known to cause a marked decline in oxidative stress, and inflammation that are crucial in the pathogenesis of NCDs. Hydrogen therapy has been found protective against NCDs, including, metabolic diseases, cardiovascular diseases (CVDs), neurodegenerative diseases, chronic kidney disease, cancer and chronic lung diseases.

There is evidence that behavioral risk factors such as western type diet, and life style can predispose to oxidative stress, deficiency in antioxidant status, hyperglycemia, dyslipidemia and increase in inflammation in tissues of various organs: beta cells of the pancreas, LDL receptors in the hepatocytes, endothelium, neurons, osteocytes and gut. Further studies indicate that diets rich in antioxidant flavonoids, omega-3 fatty acids and fiber in foods were inversely associated whereas western-type foods were positively associated with risk of mortality due to cardiovascular diseases (CVDs). One important cause for beneficial effects of diet may be certain foods and nutrients such as vegetables, fruits and whole grains that are rich in fiber and flavonoids, known to produce liters og molecular hydrogen in the gut. It seems that, high-fiber diets, prebiotic and probiotics can produce greater hydrogen, which acts as an antioxidant and may inhibit free radical generation. Recent studies indicate that molecular hydrogen can inhibit hydroxyl and nitrosyl radicals and can directly act as antioxidant in the cells and tissues, which can cause marked decline in oxidative stress and inflammation leading to significant decline in CVDs and metabolic diseases. Clinical and experimental studies indicate that hydrogen therapy such as hydrogen rich water can provide benefits in the management of CVDs and metabolic diseases. Larger studies are necessary to verify the role of hydrogen administration in CVDs.