A study published in the PLOS one journal has highlighted that increased consumption of soda and other soft drinks containing a chemical called 4-methylimidazole raises the risk of cancer. The chemical (also referred to as 4-MEI) is produced during the manufacture of caramel coloring, routinely added to many widely consumed beverages.
California labeling law currently requires that soft drinks must contain a warning label if they contain 4-Mei to pose a cancer risk of more than 1 case in every 100,000 exposed people. In 2011 4-MEI was listed as a carcinogen under the Safe Drinking Water and Toxic Enforcement of 1986, referred to as Proposition 65.
The samples tested for this study consisted of 110 samples of soda brands varying widely in 4-MEI concentrations.
The researchers cautioned against routine exposure to 4-MEI which result in exposure greater than 29 mcg a day. That particular level is associated with triggering new case of cancer in every 100,000 people consuming the drink.
Not enough data was available to recommend one drink over the other and 4-MEI levels varied substantially across samples, even for the same type of beverage.
The National Health and Nutrition Examination Survey (NHANES) was used to estimate consumers’ exposure to the 4-MEI based on consumption data. The sodas were differentiated into 5 different categories. It was determined that the proportion of the population consuming each type of soft drink varied, with “colas being the most popular and root beer and pepper colas being the least popular. Adolescents and young adults were the main consumers, consuming an average of 550-1,070 milliliters each day.
“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”, said Keeve Nachman, PhD, senior author of the study and director of the food production and public health program at the Johns Hopkins Center for a Livable Future. “This unnecessary exposure poses a threat to public health and raises questions about the continued use of caramel coloring in soda.”
Caramel color in soft drinks and exposure to 4-methylimidazole: a quantitative risk assessment, Tyler Smith, et al., PLOS One, doi:10.1371/journal.pone.0118138, published online 18 February 2015.