With the goal of finding out the harm in caramel-colored soft drinks, researchers at the Johns Hopkins Center for a Livable Future analyzed soda consumption data to learn more about exposure to a potentially carcinogenic byproduct of some types of caramel color.
The results published in PLOS One as Caramel Color In Soft Drinks And Exposure To 4-Methylimidazole: A Quantitative Risk Assessment reveal that between 44 and 58 percent of people have at least one can of soda per day and sometimes more. This consumption potentially exposes them to what is referred to as 4-MEI or 4-methylimidazole which is a possible human carcinogen that is formed during the manufacture of some caramel colors.
The study was built on an analysis of 4-MEI concentrations in 11 soft drinks whose findings were first published by Consumer Reports in 2014. A that time, 110 soft drink samples were purchased from retail stores in California and New York. The study paired those results with population beverage consumption data from the National Health and Nutrition Examination Survey so they could estimate the population risks and cancer burden associated with 4-MEI exposures through soda.
This study of 110 soda brand samples wasnt large enough to recommend one brand over another or draw conclusions about specific brands, but it did reveal that levels of 4-MEI could vary substantially across the samples and even the same type of beverage. Certain samples of diet colas, for example, had higher or more variable levels of the compound while other samples had very low concentrations.
There were also sharply contrasting levels of 4-MEI in some soft drinks that were purchased in the New York metropolitan area. And some of the soft drink products sold in California had lower levels of 4-MEI than ones sold outside of the state. It appears that regulations such as Californias Proposition 65 may be effective at reducing exposure to 4-MEI from soft drinks, and that beverages can be manufactured in ways that produce less 4-MEI, said Keeve Nachman, PhD, senior author of the study and director of the Food Production and Public Health Program at the Center for a Livable Future and an assistant professor at the Johns Hopkins Bloomberg School of Public Health. An FDA intervention, such as determining maximum levels for 4-MEI in beverages, could be a valuable approach to reducing excess cancer risk attributable to 4-MEI exposure in the U.S. population. Soft drink consumers are being exposed to an avoidable and unnecessary cancer risk from an ingredient that is being added to these beverages simply for aesthetic purposes. This unnecessary exposure poses a threat to public health and raises questions about the continued use of caramel coloring in soda.
This new analysis underscores our belief that people consume significant amounts of soda that unnecessarily elevate their risk of cancer over the course of a lifetime, added Urvashi Rangan, PhD, executive director for Consumer Reports' Food Safety and Sustainability Center. We believe beverage makers and the government should take the steps needed to protect public health. California has already taken an important step by setting a threshold for prompting Prop 65 labeling based on daily 4-MEI exposure from a food or beverage, such as a soda.