In "Caramel Color: The Health Risk That May Be in Your Soda," we reported on the results from our tests of 110 samples of soft drinks, which showed that they contained varying levels of a possible human carcinogen called 4-MeI. This chemical is a by-product of the production of some types of caramel color. Here’s more background information on this food coloring to help you make the best choice for your health.
1. How harmful can caramel coloring be? Isn’t it just made from sugar?
Forget about images of bubbling sugar turning golden brown in a pan on your stove. The artificial caramel colors that are added to foods and beverages are highly processed products sold as powders and liquids. The types of caramel colors used in sodas generally are made by heating corn syrup along with ammonia and sulfite compounds. The presence of ammonia compounds during the manufacturing process causes a chemical reaction that creates 4-MeI.
2. Why should I worry about 4-MeI if it only has been shown to cause cancer in mice and not in people?
Animal studies are used in part because it is simply not ethical to give people a substance suspected to be a carcinogen and see what happens. Rodents are generally similar to humans in response to carcinogens, and in many cases substances that are known to cause cancer in people were initially shown to cause cancer in rodents or other lab animals. Government research has clearly shown that 4-MeI causes cancer in mice, according to John Bucher, Ph.D., associate director of the National Toxicology Program, which published the results of that work in 2007.
3. Wouldn't I have to drink thousands of cans of soda every day to reach the amount of 4-MeI given to mice in the study?
The argument that animal studies are irrelevant because they use doses much higher than what people would consume is misleading. "The fact is, when something is shown to be carcinogenic in animal studies at any level, it's a wake-up call," says Urvashi Rangan, Ph.D., executive director of the Consumer Safety and Sustainability group at Consumer Reports. There are many reasons why toxicology studies designed to detect a cancer risk are typically conducted at high doses, including the lifespan of the animal and the number of animals that can reasonably be used in a study. And researchers must extrapolate the results in order to determine the risks posed by a dose that people would likely be exposed to in real life. "The nature of the relationship between the escalating doses of a chemical and the risk of cancer seen at higher doses can be used to make predictions about risks at lower, more realistic doses," says Keeve Nachman, Ph.D., director of the Food Production and Public Health Program at Johns Hopkins Center for a Livable Future, which partnered with Consumer Reports in testing the 4-MeI content in sodas. In the government research, mice were given varying doses of 4-MeI and the scientists found that as the dose went up, the risk of tumors increased.
4. What other foods and beverages might contain 4-MeI?
There are actually four classes of caramel coloring, two of which can contain 4-MeI. Those types may be found in a variety of products, including beer, breads and other baked goods, dark sauces such as soy or barbecue sauce, pancake syrups, soups, and even pet foods. But we don't know how much 4-MeI those foods contain.
5. How much soda do Americans drink anyway?
A lot. Carbonated soft drinks are second only to tap water as the most popular beverage in the U.S., with 64 percent of Americans drinking soda at least six times a week, according to 2013 data from Kantar, a market-analysis group. The latest data on sales of colas and other soda released by Euromonitor International shows that on average, Americans bought more soda than residents of 80 other countries—almost 44 gallons, or about 466 12-ounce cans, per person in 2012.
6. Does caramel color do anything except make foods and drinks darker?
Caramel coloring generally has no effect on flavor. It's primary purpose is to add color to a food or drink. In fact, both PepsiCo and Coca-Cola marketed clear colas—Crystal Pepsi and Tab Clear—in the 1990s.
7. Does Consumer Reports recommend one brand of soft drink over another as a result of its tests?
Our sample size was not big enough for us to draw conclusions about brands or to recommend one over another. That being said, we found levels of 4-MeI in some of our samples that our experts believe pose too high a risk, particularly if you consume other foods with caramel coloring.
8. Do I have to worry if I drink only one or two cans of soda with caramel color a week?
It's hard to say. Consider how many other foods and drinks with caramel color that you may have in your diet during the course of an average day. The less caramel color with 4-MeI that you consume, the lower your risk.