How much gold can you safely eat?
Photo by Mackenzie Keegan.
A New York City food truck is selling a $666 hamburger dubbed the “Douche Burger,” which contains lobster, caviar, truffles, and a beef patty wrapped in six sheets of gold leaf. How much gold leaf can you safely consume?
Theoretically, you could eat your fill of 24-karat gold without falling ill. Pure gold is chemically inert and passes through the human digestive system without being absorbed into the body. Since 24-karat gold is very soft and fragile, most edible gold—whether leaf, flakes, or dust—also contains a little bit of silver, which is also inert. Non-edible gold leaf, which is used for gilding, sometimes contains copper, which can be toxic in high doses. Consuming impure gold preparations such as colloidal gold or gold salts can lead to a change in skin pigmentation and other adverse health effects. Eating too much pure gold might give you a stomachache, just like eating too much of anything else might, but it won’t have any more dire effects unless you’re among the minority of people who are allergic to gold.
The FDA hasn’t evaluated edible gold leaf for safety, but the Centers for Disease Control and Prevention’s Agency for Toxic Substances and Disease Registry doesn’t consider gold a toxic substance. Gold is an approved food additive in the European Union, and an independent European food-safety certification agency, TÜV Rheinland, has deemed 23-karat gold leaf safe for consumption. Gold and silver leaf are also certified kosher.
Europeans have been adding gold leaf to food and liquor (like Danziger Goldwasser) since the Renaissance, and gold leaf can also be found adorning certain Japanese candies and South Asian pastries. Homeopaths have prescribed gold as a treatment for heart disease, arthritis, depression, and other ailments for hundreds of years, but gold’s usefulness as a medicine has not been demonstrated.
Edible gold leaf has no taste, texture, calories, or expiration date. It can cost $120 to $160 per gram. A gram of edible gold would add a dash of glitter to 150 to 200 champagne flutes, or wrap about 4 Douche Burgers.
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Explainer thanks Franz Aliquo of 666 Burger and Tobias Freccia of ediblegold.com.
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L.V. Anderson is a Slate assistant editor. She edits Slate's food and drink sections and writes Brow Beat's recipe column, You're Doing It Wrong. Follow her on Twitter.