Caramel colour, used in colas, contains potentially-carcinogenic 4-MeI

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.