Hydrogen sulfide: is the name of the gas that emanates from rotten eggs and also from certain sulphurous baths. This colorless and flammable gas was also used in the First World War as a chemical weapon. But now entire congresses are dedicated to studying the properties of this gas, which is produced, albeit slowly, within the human body. Research, in China and elsewhere, has led to surprising conclusions: hydrogen sulphide can extend life, in at least three ways. First, it keeps so-called free radicals, which damage cells, under control. Second, it stimulates the production of an enzyme, SIRT1, which is considered a regulator of life span and produces the same effects as a calorie restriction. Third, it interacts with a gene, Klotho, which stimulates the production of its own anti-oxidants within the human body. Klotho was named after a Greek mythological figure, one of the 'fates' who controlled the length of men's lives.
Some property are analogous to those of resveratrol, an anti-oxidant found in red wine, which GlaxoSmithKline has tried and failed to turn into a medicine. Unlike resveratrol, hydrogen sulfide, as mentioned, is already present in the body. Diets high in onions, garlic, and other plants in the Allium family are rich in compounds that can release or generate hydrogen sulfide.
http://www.bloomberg.com/news/2013-02-18/rotten-egg-gas-seen-offering-promise-of-extending-life.html
