The US Centre for Science in the Public interest (CSPI) have claimed that the caramel food colouring typically used in cola drinks could cause cancer.
Pure caramel is made from melted sugar, and the brown colouring is made by reacting these sugars with the chemical ammonia and sulphites under high pressures and temperatures. This reaction creates two substances known as 2-MI and 4-MI which have previously been linked by the US Government to lung, liver and thyroid cancers in tests. America’s National Toxicology Program states that these two substances are animal carcinogens and do pose risks to humans.
There are four types of caramel food colourings used in foods, two of which are produced with ammonia. The Executive Director of CSPI, Michael F. Jacobson has petitioned to remove the two carcinogenic colourings from the food supply, which has support from the National Toxicology Program. The CSPI has admitted that the risk associated with the carcinogenic chemicals is still very low, but the levels of 4-MI found in samples of colas could contribute towards deaths caused by cancers. However it should be noted that the typical ten teaspoons of sugar found inside just one can of typical cola provide a greater health risk.