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Popular Soda Additive Unnecessarily Exposes Consumers to Potential Carcinogen

Jan 27, 2014

A common color additive found in several popular soft drinks and sodas may be linked to an increased risk of developing cancer among soda consumers. This is according to a new report led by researchers at the Johns Hopkins Center for a Livable Future (CLF) and Consumer Reports which examined the use of 4-methylimidazole (4-MEl), a potential carcinogenic chemical byproduct of certain types of caramel color used in various soft drinks and sodas. The researchers found that among the 12 brands of sodas and soft drinks tested, varying levels of 4-MEI were found in all samples that listed caramel color as an ingredient. The results are featured online at Consumer Reports.

"We found residues of 4-MEI, a chemical shown to be carcinogenic in mice, across a number of different soda brands," said Keeve Nachman, PhD, MHS, study investigator and director of the Food Production and Public Health Program with the CLF. "While the study was not large enough to be able to recommend one brand over another, we did see striking differences in 4-MEI levels among the products tested, which could suggest that long-term consumption of certain products may carry a greater cancer risk than others." The study found the highest levels of 4-MEI in the products Malta Goya and Pepsi One, where consumption of a single daily serving would result in a 4-MEI intake of more than 300 micrograms and 39 micrograms of 4-MEI per day, respectively.

Current federal laws do not limit the amount of 4-MeI allowed in foods or beverages, but the state of California requires a warning label be present on products exposing consumers to more than 29 micrograms of 4-MEI per day. While the study's researchers could not conclude that any of the products tested should have required a warning label, they were concerned with the high levels they found. Caramel coloring is a color additive that may contain carcinogens which previous studies have linked to certain types of cancer.

Researchers collected and tested 81 cans and bottles of popular brands of soft drinks from April -September 2013 purchased in California and the New York tri-state area. Additional samples were purchased and tested in December 2013. Tests were conducted on sodas from five manufacturers including Pepsi, Coca-Cola, the Dr Pepper Snapple Group and Goya. Researchers found that when listed as an ingredient, caramel coloring could be an indication of 4-MEI. This has led researchers to recommend individuals limit their consumption of beverages containing caramel coloring.

"A few companies have already reduced 4-MEI in soda and the FDA [Food and Drug Administration] should compel their competitors to follow suit," added Tyler Smith, study investigator of the report and a program officer with the CLF. "Like Europe already does, the FDA should also require companies to specify the type of caramel color on product labels so the public can make informed choices."

Johns Hopkins Center for a Livable Future media contact: Natalie Wood-Wright at 443-287-2771 or