Caramel colour, a common ingredient in colas and other dark soft drinks, has turned out to be carcinogenic, according to recent studies. 44 to 58 % of people over 6 years of age usually have at least one can of soda every day, even more, therefore exposing themselves to 4-methylimidazole or 4-MEI, which is a  human carcinogen that’s formed as a consequence of the manufacturing procedure of some kinds of caramel colour.

The researchers at the University Bloomberg School of Public Health published the study online in the notorious journal PLoS One.

“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 esthetic purposes,”

Prof. Keeve Nachman, senior author of this study and also director of the food production and public health program at the Centre for a Livable Future (CLF) of the University said.

A 2014 study of 110 samples of soda brands tried to look into the same matters, but it was not large enough so as to be capable of  recommending one brand instead of another or to draw conclusions regarding specific brands. However results indicated clearly that levels of 4-MEI could very well vary substantially among samples, even for samples representing the same type of beverage.

The samples used in the study mostly came from California and New York, regarding to which researchers noted that soft drinks in California tend to have lower levels of 4-MEI than the samples sold outside the state of California. This is because food and drink manufacturers are compelled by the California state law to post warning labels on any products that expose consumers to more than a specific amount of 4-MEI each day.

There’s currently no federal limit regarding 4-MEI in neither food nor beverages despite the fact that the US Food and Drug Administration has been petitioned to set limits for this potential carcinogen ingredient last year.

California has already taken an important step towards the 4-MEI regimentation by setting a threshold for prompting Proposition 65 labelling based on daily 4-MEI exposure. Moreover intervention by the FDA, such as establishing maximum levels for 4-MEI in beverages, may represent a valuable approach towards reducing cancer risk.