Caramel colour (which was among the most used food colours in the
world, according to a 2013 report from market research firms Mintel and
Leatherhead Food Research) is added to many soft drinks and some foods
to turn them brown. However, it does not resemble real caramel. Some
types of this artificial colour contain a potentially carcinogenic
chemical called 4-methylimidazole (4-MeI).
Under California’s Proposition 65 law, any food or beverage sold in
the state that exposes consumers to more than 29 microgram 4-MeI per day
is supposed to carry a health-warning label.
In recent tests by Consumer Reports, each of the 12-ounce samples of
Pepsi One and Malta Goya had more than 29 micrograms per can or bottle.
While this cannot be said to be in violation of California’s Prop 65,
these levels are too high, and California’s attorney general has been
requested to investigate.
“There’s no reason why consumers should be exposed to the risk that
can stem from colouring food brown,” said Urvashi Rangan, toxicologist
and executive director, Food Safety and Sustainability Centre, Consumer
Reports.
She added, “Lower 4-MeI alternatives are available to manufacturers. Ideally, foods should not contain 4-MeI.”
The risks
In 2007, a federal government study concluded that 4-MeI caused cancer
in mice, and the International Agency for Research on Cancer determined
the chemical to be “possibly carcinogenic to humans” in 2011.
There’s no federal limit for levels of 4-MeI in foods and beverages,
but on January 7, 2012, California stated that manufacturers must label a
product sold in the state with a cancer warning if it exposes consumers
to more than 29 micrograms of 4-MeI per day. In this case, the exposure
comes from consumption.
The California Office of Environmental Health Hazard Assessment used
29 micrograms as the cut-off point because that was the level they
determined posed a one in 100,000 risk of cancer (that is, no more than
one excess cancer case per 100,000 people who are exposed to that amount
daily for a lifetime).
Consumer Reports’ experts think even that risk is too high. “It’s
possible to get more than 29 micrograms of 4-MeI in one can of some of
the drinks we tested. And even if your choice of soft drink contains
half that amount, many people have more than one can per day,” stated
Rangan.
“Given that colouring is deliberately added to foods, the amount of
4-MeI in them should pose a negligible risk, which is defined as no more
than one excess cancer case in a million people.” To meet that risk
level, Consumer Reports’ experts say a soft drink would need to contain
about three micrograms or less per can.
Testing
Consumer Reports tested 81 cans and bottles of various popular brands
of soft drinks from five manufacturers between April and September
2013. The products were bought from stores in California and the New
York metropolitan region.
In December 2013, 29 new samples of the brands that initially tested
above 29 micrograms per can or bottle in either location were bought and
tested from the same areas.
Findings
While Consumer Reports’ study was not large enough to recommend one
brand over another, both rounds of testing found that the level of 4-MeI
in the samples of Pepsi One and Malta Goya purchased in both locations
exceeded 29 micrograms per can or bottle.
The products purchased in California did not have a cancer-risk warning label.
During the initial testing, the researchers found that some of the other
brands bought in California had average levels around or below 29
micrograms per can, but the New York area samples of those same brands
tested much higher.
However, in the second test, the levels in the New York samples had
dropped. For example, regular Pepsi from the New York area averaged 174
micrograms in the first test and 32 micrograms in the second.
“The fact that we found lower amounts of 4-MeI in our last round of
tests suggests that some manufacturers were taking steps to reduce
levels, which would be a step in the right direction,” said Rangan.
On average, three brands (Coke, Diet Coke, and Coke Zero) came in
under 5 micrograms per can in the tests, a level Consumer Reports’
experts believed was more acceptable. Sprite, a clear soda that was
tested as a control, showed no significant levels of 4-MeI.