Gold, the element with the chemical symbol Au, is valued for its luster and resistance to corrosion. When considering its role in human health, the answer to whether it is beneficial depends entirely on the form it takes. The medical and health applications of gold range from inert physical components in the body to potent pharmaceutical agents.
Safety Profile of Elemental Gold
The pure metallic form of gold, such as 24-karat gold, is generally considered chemically inert within the human body. This inertness is a major factor in its long-standing use in medical and dental fields. This property allows it to be used as a food coloring agent (E175) or in decorative flakes, as it is largely unabsorbed by the digestive system.
Small amounts of elemental gold, particularly nanoparticles, can be absorbed in the gastrointestinal tract. It distributes to organs like the liver and kidneys before being excreted through urine. While acute toxicity is low, there is a recognized risk of developing hypersensitivity or allergic reactions to gold ions released from dental restorations or other prolonged contact points.
Gold Compounds in Modern Pharmacology
Gold’s established medicinal use is found not in its metallic form, but in specific chemical formulations called gold salts. These compounds, such as Auranofin or injectable gold sodium thiomalate, are prescribed treatments for certain autoimmune diseases, most notably Rheumatoid Arthritis (RA). These gold salts are classified as Disease-Modifying Antirheumatic Drugs (DMARDs) because they reduce joint inflammation and slow the progression of joint damage.
The therapeutic action involves the gold compound’s ability to modulate the immune response. Gold salts accumulate within immune cells, such as macrophages, where they interfere with processes like antigen presentation and the production of pro-inflammatory signaling molecules called cytokines. These compounds also inhibit enzymes, like thioredoxin reductase, which play a role in oxidative stress and inflammatory pathways.
Because they are chemically active, gold salts can produce significant side effects, requiring careful medical monitoring with blood and urine tests. Common adverse effects for oral Auranofin include gastrointestinal issues like diarrhea, while injectable forms are associated with skin rashes and mouth sores. More serious complications can involve toxicity to the kidneys (proteinuria) and the bone marrow (thrombocytopenia).
Structural and Implant Applications
Beyond its chemical activity as a drug, gold is highly valued in medicine for its physical properties, making it an excellent material for structural components and implants. The metal’s exceptional resistance to corrosion is a primary asset, ensuring that it remains stable when exposed to the body’s moist internal environment over long periods.
In dentistry, gold alloys have been used for centuries in crowns, inlays, and fillings due to their malleability, which allows for precise fitting, and their durability against chewing forces. The metal’s inherent biocompatibility means it causes minimal adverse reaction when placed adjacent to human tissue, a major requirement for any permanent implant. This non-reactive quality extends to other medical devices, where gold is used in components such as endovascular stents and certain micro-implants.
Evaluating Alternative Gold Supplements
The market offers various unregulated products, such as “colloidal gold,” which are often promoted as general wellness or cognitive enhancement supplements. Colloidal gold consists of gold nanoparticles suspended in liquid, distinct from the gold compounds used in prescription medicine. Despite marketing claims, scientific evidence supporting the health benefits of these supplements is currently lacking.
These products are not subject to the same rigorous testing and approval process as pharmaceutical drugs. Over-consumption or prolonged use of gold supplements can lead to a condition called chrysiasis, where gold deposits in the tissues cause a persistent grayish-blue discoloration of the skin and eyes. While research is ongoing into the potential of gold nanoparticles for targeted drug delivery, commercially available colloidal gold products should be viewed with skepticism.