PepsiCo - which was named in the study for comparatively high levels of 4-MEI - says all its US products meet stricter Californian standards, accusing the study of containing outdated information.
Meanwhile, the FDA official position maintains there is no immediate or short-term danger from 4-MEI in food and drink.
Published in the journal PLOS One this week, Keeve Nachman (an assistant professor at John Hopkins Bloomberg School of Public Health) and colleagues took a 2014 analysis of 4-MEI concentrations across 11 soft drinks (including several Pepsi varieties); estimated exposure to 4-MEI from caramel-colored soft drinks; and then modelled the potential cancer burden.
“Based on 4-MEI concentrations observed in beverage samples from this study, it appears that 4-MEI exposures associated with average rates of soft drink consumption pose excess cancer risks exceeding one case per 1,000,000 exposed individuals, which is a common acceptable risk goal used by some US federal regulatory agencies,” wrote Nachman in the study.
“Specifically, consumption of Malta Goya, Pepsi, Diet Pepsi and Pepsi One resulted in 4-MEI exposures with associated risks exceeding one excess case per 10,000 exposed individuals, suggesting that the risk can greatly exceed this threshold.”
But PepsiCo responded to the figures, telling BeverageDaily.com that “The study contains outdated information. The 4MEI figures reported in this study do not reflect what is currently available in the U.S. marketplace."
California’s Proposition 65 includes 4-MEI as a carcinogen, and the legislation requires beverage companies to display a health warning if 4-MEI exceeds a certain level. Consequently, the study found some Californian beverages had lower levels of 4-MEI than those in other states.
PepsiCo continues: “Today all Pepsi products in the United States meet California’s Prop 65 requirements.”
The FDA (US Food and Drug Administration) official positions says ‘there is no reason to believe that there is any immediate or short-term danger presented by 4-MEI at the levels expected in food from the use of caramel coloring.’ Although it is reviewing safety data, it says it is not currently recommending consumers change their diets because of concerns about 4-MEI.
The American Beverage Association (ABA) also insists caramel coloring is safe.
“Leading regulatory and public health organizations around the world have repeatedly confirmed its safety,” said Christopher Gindlesperger, senior director for public affairs.
“In fact, the FDA has noted that there is no reason at all for any health concerns and that as a consumer you ‘would have to drink more than a thousand cans of soda in a day to match the doses administered in studies that showed links to cancer in rodents.'”
However, the study's senior author Keeve Nachman, from John Hopkins Bloomberg School of Public Health, told this website: "We stand by the results of our study."
BeverageDaily.com also contacted Goya Foods for comment; you can read the company's full response here.
Story updated with study author's response, February 26 2015.