Public health researchers looking at U.S. soda
drinking habits warn that many people may be
regularly exposing themselves to a potentially
cancer-causing byproduct of the caramel coloring
used in some types of soda.
Caramel color is a
common ingredient in colas and other dark soft
drinks, and a possible human carcinogen
—4-methylimidazole (4-MEI)— is formed during the
manufacture of some kinds of the coloring. Analysis
of soda consumption data show that between 44 and 58
percent of people over the age of 6 typically have
at least one can of soda per day.
Building on an analysis
of 4-MEI concentrations in 12 different soft drinks
first published by Consumer Reports in 2014,
researchers led by a team at the Johns Hopkins
Center for a Livable Future estimated exposure to
4-MEI from caramel-colored soft drinks and modeled
the potential cancer burden related to routine soft
drink consumption levels in the U.S.
"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,"
says Keeve Nachman, senior author of the study,
director of the Food Production and Public Health
Program at the center, and an assistant professor at
the Johns Hopkins Bloomberg School of Public Health.
"This unnecessary exposure poses a threat to public
health and raises questions about the continued use
of caramel coloring in soda."
While there's currently
no federal limit for 4-MEI in food or beverages,
Consumer Reports petitioned the Food and Drug
Administration to set limits for the potential
carcinogen last year. It also shared the findings
with the California attorney general's office, which
enforces the state's Proposition 65 law aimed at
reducing consumers' exposure to toxic chemicals.
Under this state law, any food or beverage sold in
the state that exposes consumers to more than 29
micrograms of 4-MEI per day requires a
health-warning label.
In 2013 and early 2014,
Consumer Reports partnered with the Center for a
Livable Future to analyze 4-MEI concentrations of
110 soft drink samples purchased from retail stores
in California and the New York metropolitan area.
The analysis found by far the highest concentration
in Malta Goya, a non-alcoholic malt beverage that is
popular in Caribbean nations. Samples of Pepsi One,
Diet Pepsi, and Pepsi also scored above the 29
microgram per can/bottle level in some instances.
Coke, Diet Coke, Coke Zero, and Dr. Pepper scored
well below the 29 microgram threshold in two tests;
Sprite was shown to contain no significant levels of
4-MEI.
The more recent study
pairs those results with population beverage
consumption data from the National Health and
Nutrition Examination Survey in order to estimate
the population risks and cancer burden associated
with 4-MEI exposures through soda. While the 2014
study of the 110 samples of soda brands was not
large enough to recommend one brand over another or
draw conclusions about specific brands, results
indicated that levels of 4-MEI could vary
substantially across samples, even for the same type
of beverage. "For example, for diet colas, certain
samples had higher or more variable levels of the
compound, while other samples had very low
concentrations," says Tyler Smith, lead author of
the study and a program officer with the Center for
a Livable Future.
"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," says Urvashi Rangan, 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. This study
sought to answer a critical question: How much soda
do American consumers drink on average?"
For more information
PLOS ONE
Caramel Color in Soft Drinks and Exposure to
4-Methylimidazole: A Quantitative Risk Assessment
Popular Soda Ingredient Poses Cancer Risk to
Consumers
Marco Dal Negro |