Human consumption of gold

Metallic gold is used by the alchemists to prepare a liquid that they affirm will restore youth when drunk." -Agricola, De natura fossillium, 1546.

In what ways is gold consumed? About 75% of the gold produced in the world's mines goes to jewelry production. This is one meaning of the term "consumption".  More surprising are the many ways in which gold actually finds its way into the human body.

Gold crowns are still the best. Although rapidly being replaced with less-expensive alternatives, dental amalgams containing high percentages of gold are still desirable as crowns. Gold is a soft metal, and its use in a crown lessens the stress put on the opposing tooth in the act of chewing. Modern porcelain crowns are much more brittle than gold, and are not likely to last the decades that gold crowns can.

Gold also has medical uses. An isotope of gold, 198-Au, which has a half-life of 2.7 days, is used in treating some cancers and other diseases, and also as a tracer within the human body. A compound containing gold known as disodium aurothiomalate, is used in an injection as a treatment for arthritis. Auranofin, a complex organic molecule, is used in the treatment of some cases of rheumatoid arthritis.

Serve gold at your next party. Gold in the form of extremely fine leaf (a few atoms in thickness) has been added to certain liqueurs from Eastern Europe, such as Goldwasser. This gives the liquid a sparkle in the glass, as the fine bits of gold catch the light as they float suspended. Pure gold leaf has a long tradition in cuisine both in Europe and the Far East. Exotic dishes are given the ultimate exotic presentation, wrapped in 99.9% pure gold leaf so unbelievably thin, that the gold itself is edible.

Although consumption of gold is essentially harmless in small amounts, there is a gold toxicity that is known from its use in treating arthritis. Skin rash is the most common result of excessive consumption of gold for medicinal purposes. Gastrointestinal distress can from time to time result from excessive ingestion of gold compounds.

A commonly used antidote is Dimercaprol, HSCH2CHSHCH2OH, also called BAL (British Anti-Lewisite). BAL forms a stable complex with gold, rendering it physiologically ineffective and easy to eliminate from the body. Certain people develop a mild rash from wearing gold jewelry, although this phenomenon is not entirely understood today. This dermatitis may be caused by residual radioactivity in the minor alloys in the jewelry.

Gold can be harmful in other ways. Of course, the most harmful aspects of gold to humans have nothing to do with actual gold consumption. More dangerous is that wide range of disorders, known collectively as "gold fever" (see Bogart, Humphrey, "The Treasure of the Sierra Madre.").