The hidden carcinogen in Soda

We all know that soda packs lots of addictive sugar. Few of us know that soda has another ingredient that’s worth knowing about.

Some caramel-colored sodas could contain a potential carcinogen, suggests a new study from Johns Hopkins University.

Caramel color is a dark brown food additive. It helps give drinks such as cola their special hue. The one you think as ‘natural’ (ha ha!) It’s made by heating and caramelizing sugars. Sounds simple, right?

The problem is this: some types of caramel color are made using chemicals such as ammonium hydroxide to push along the caramelization process. During the  chemical reactions, something called 4-methylimidazole (4-MEI) can form.

 Studies of lab mice and rats suggest that 4-MEI can cause cancer, and the International Agency for Research on Cancer classifies it as “possibly carcinogenic to humans.”

Researchers tested 12 sodas purchased in California and New York for 4-MEI content. They found a wide range, from 9.5 micrograms per liter to up to 915 micrograms per liter. The sodas with the highest 4-MEI levels were Malta Goya and the New York samples of Pepsi, Diet Pepsi, and Pepsi One.

Researchers estimated that consumption of the studied drinks could contribute to anywhere from 78 to 5,011 extra cancer cases in the U.S.

In some cases, drinks sold in California had lower levels of 4-MEI. California’s Proposition 65 law lists 4-MEI as a carcinogen and requires manufacturers to include a warning label on products with more than 29 micrograms of the chemical. It seems that the manufacturers used a different formula for products sold in California in order to comply with the state’s regulations, says study author Keeve Nachman, Ph.D., MHS.

So is there good news? Both PepsiCo and Goya have released statements saying that they’ve reduced levels of 4-MEI in their products since these researchers took their samples. They say that all products now meet the California standards.

Still, it’s possible that there’s no truly safe level of intake of 4-MEI, says Nachman. If you’re concerned about exposure to the potential carcinogen, it’s smart to read labels and choose products that don’t contain caramel color.

Ideally, the Food and Drug Administration (FDA) will step in and regulate this chemical. “What we think makes the most sense is for the FDA to set a tolerance level for the formation of 4-MEI for the caramel color that’s used in beverages,” says Nachman.

Possible risks of caramel color don’t come with much benefit. “One other dimension to this whole thing is it’s not like the caramel color itself really serves an important function,” says Nachman. “Caramel color is just for changing the color of the beverage. It doesn’t play a role in flavor or preservation.”