Gold is usually associated with jewellery or investment, but the precious metal has many other important uses in modern life, from smartphones and computers to spacecraft, medicine and even food. It does not corrode or rust easily, conducts electricity effectively, and can be formed into very thin sheets or fine wires. These properties make it useful across technology, medicine and industry.
In food, gold is used in a form known as edible gold, usually 22 to 24 carats and very thin. It decorates expensive items such as sushi, sweets, chocolate, cakes and ice cream. The European Union approves gold as a food additive under the code E175. However, there is no evidence that eating gold provides special nutritional benefits. Metallic gold is not significantly absorbed by the human digestive system because of its low solubility. Its main purpose in food is beauty and luxury. In South Asia, gold or silver leaf, commonly called varak or wark, has long been used to decorate sweets. A 2023 study published in Particle and Fibre Toxicology fed gold to rats for 90 days and found no direct damage to the liver, spleen or intestines, though some changes were observed in gut microbiota and the immune system.
Smartphones and computers also contain gold. Although the amount in each device is very small, it is important. Gold is used in circuit boards, connectors, switches and other electrical connections in computers, tablets and similar devices. Because it conducts electricity easily and resists rust and corrosion, it helps keep electrical connections working for a long time. The total use of gold in electronics is significant because so many technology products are made worldwide. There are also systems for collecting and reusing gold from old mobile phones, computers and other electronic waste.
Gold also plays an important role in space technology. It reflects light and heat radiation well and retains its brightness for a long time. The James Webb Space Telescope’s mirrors are coated with a very thin layer of gold, which is especially effective at reflecting infrared light. This helps the telescope collect data on distant stars, galaxies and cosmic objects. Gold is also used in astronaut helmets: the transparent part covering the eyes and face is coated with a thin gold layer that acts like sunglasses and protects astronauts from intense solar rays. Various spacecraft components and electrical connections also use gold because of its conductivity and corrosion resistance.
In medicine, gold has been used for a long time. Some gold compounds, or gold salts, were once used to treat rheumatoid arthritis, though their use has declined significantly because more effective drugs are now available. Research continues into new uses, including tiny gold nanoparticles for diagnosing diseases, delivering drugs to specific areas of the body, and detecting and treating cancer. Gold nanoparticles are also used in some rapid diagnostic test kits, where they help create the coloured lines that show results. Gold and gold alloys have long been used in dentistry to repair or reconstruct teeth because they resist decay and last a long time, although high cost and alternative materials have reduced their use.
Gold is also important to national economies. Central banks around the world store large amounts of gold as reserves alongside foreign currencies. At one time, a large portion of central bank reserves consisted of gold, and the value of some currencies was linked to gold reserves. Many countries still hold part of their foreign exchange reserves in gold. According to the World Gold Council, the United States has the largest gold reserves, about 8,133 tonnes. IMF data show that the central banks of the United States, Germany, Italy and France collectively held about 16,400 tonnes of gold in 2024, and more than 70 percent of these countries’ foreign reserves are made up of gold. China has also been increasing its gold reserves. According to the World Gold Council, China’s gold reserves were about 2,279 tonnes at the end of 2024, and the country bought about 19 more tonnes in the first six months of 2025. The United States did not buy any new gold during that period. Earlier, in 2023, China bought about 88 tonnes of gold. These areas show how widespread gold’s importance is in modern economics, technology, medicine and space exploration, far beyond its familiar roles in jewellery and investment.
