Dear Straight Dope:
I recently read the article concerning fish scales in women's lipstick. I am in the food garnishment business and get many questions about the use of food garnishes made of 24K gold. We have used gold in some products for the luster and look--for example, painted on cookies or sprinkled on cakes. Martha Stewart promotes the product and uses it in many of her decorative demonstrations. But is it safe to eat? I have been told by the FDA and companies that sell the product that 24K gold is fully edible--it isn't absorbed into your bloodstream and doesn't enter the system. There are even silver products for sale, but my sources don't say whether they're edible, and it's difficult to get a direct answer from the FDA. I don't want to use a product unless it has been deemed completely safe and fit for human consumption. I am very interested in the straight dope on glossy-shiny pearl essence for food garnishment.
SDStaff Ken replies:
Relax (if that’s possible in the catering business). The gold you use is harmless. According to my sources, gold does not react with anything. It’s unaffected by moisture, oxygen, or ordinary acids but is attacked by the halogens. Aqua regia (a mixture of nitric and hydrochloric acids that liberates chlorine) is so named for its ability to dissolve gold, the “king” of metals. If your stomach has aqua regia floating around in it, eating gold would be the least of your worries–the hole in your stomach lining would be a higher priority, I’m guessing. Gold has no nutritive value, fats or carbs, so the body does with it what it does with all other non-foods–passes it out as quickly as possible. (Insert optional golden toilet bowl joke here.) Same story with silver, but it’s a little more reactive than gold. Normal stomach acids can act on it, and in a substantial amount (we’re talking two tablespoons or more), can cause nausea and/or vomiting. To be on the safe side, then, I’d say go for the gold.
Send questions to Cecil via firstname.lastname@example.org.
STAFF REPORTS ARE WRITTEN BY THE STRAIGHT DOPE SCIENCE ADVISORY BOARD, CECIL'S ONLINE AUXILIARY. THOUGH THE SDSAB DOES ITS BEST, THESE COLUMNS ARE EDITED BY ED ZOTTI, NOT CECIL, SO ACCURACYWISE YOU'D BETTER KEEP YOUR FINGERS CROSSED.