While you may not have heard of 4MeI (4-Methylimidazole), you have almost certainly been eating and drinking it. A component of caramel coloring, 4MeI is the most common food-coloring chemical in the world. Most notably, it helps gives cola its signature brownish color. Over the years, a number of public health advocates and consumer groups have expressed concern about 4MeI’s safety because animal studies have repeatedly shown it causes cancer (that is, it’s carcinogenic).
Animal studies are usually not sufficient to designate a chemical as a human carcinogen and thus ban it or phase it out. But the animal data on 4MeI is compelling and based on these the International Agency for Research on Cancer—the world’s most authoritative body on carcinogens–designates 4MeI as a “possible human carcinogen.” That’s the strongest designation allowed without human studies.
Evidence in people is typically the critical part of earning the label “carcinogen.” Yet there are no human studies of 4MeI–it bears repeating, the most common food-coloring chemical in the world.
Carcinogens in a Can? (Or Bag, Box, Bottle….)
Scientists at Consumer Reports recently determined a safety threshold of 3 micrograms of 4MeI per serving. All popular cola brands, iced teas and other brown soft drinks–regular and diet—go over that amount in a single can. Some drinks exceed it by as much as 100 times. Besides soft drinks, food manufacturers use 4MeI in coffee, bread, snack food, beer and soy sauce.
Cigarette smoking, obesity and sedentary lifestyle are the major causes of cancer. Still, cancer risks from other sources should be more transparent, especially those in what we eat and drink. Furthermore, manufacturers and regulatory agencies should enact stricter guidelines to test safety and better mechanisms to appropriately communicate risks to consumers.
February 7 editing correction: “probable human carcinogen” changed to “possible human carcinogen.”