Not quite the same as the tasty caramel we get when we melt sugar, caramel color—seen on the ingredient labels of many popular soft-drinks—is an artificial coloring agent recently brought into the public spotlight for its suggested negative health effects. In response to safety concerns voiced by third-party, unbiased organizations, the food industry has defended their manufacturing practices. Here, we break down the science in an effort to encourage better-informed dietary decisions.
Caramel Color 101
Caramel color production always starts with a carbohydrate source and high heat. Subsequent modifications, however, alter their chemistry, physical properties, and, importantly, their effects in the human body. The resulting compound is classified into one of four categories, depending on method of production.
- Class I: No ammonium or sulfites. Used in high-proof alcohols.
- Class II: Sulfites added, no ammonium. Used in some cognac, sherry and vinegars.
- Class III: Ammonium compounds added, no sulfites. Used in some beers, sauces, and candy.
- Class IV: Ammonium and sulfites added. Used in soft-drinks.
Concern over Caramel Color Health Effects
Recent concerns have been directed to caramel colors prepared with ammonia (class III and IV caramels). Processing carbohydrates with ammonia under high temperatures can produce a toxic byproduct, 4-methylimidazole (4-MeI), that has been linked to convulsions and an increased incidence of cancer in animal testing.
High doses of 4-MeI (360mg/kg) were found to have convulsive effects in rabbits, mice, and chicks. In 2007, a National Toxicology Program (NTP) study discovered that high doses of 4-MeI were clearly correlated to carcinogenicity in mice and female rats. In the study, both male and female mice “had a significant increase” in the incidence of lung-cancer, with males showing slightly greater tolerance than the females. In the rat study, females saw an increase in the leukemia rates as well as negative consequences for the lungs, heart, pancreas, and thyroid. Males did not experience a statistically significant increase in cancer rates, but did have abnormal inflammation of the prostate and hypertrophy (enlargement) of the pituitary gland. Other side effects, including “hyperactivity, excitability, and impaired gait” were noticed in female rats at “some or all dosage levels in a dose-dependent way.”
It should be noted that effects seen in animals do not definitively demonstrate that humans will respond in similar ways, but it does lend probability and legitimacy to possible health concerns.
Regulatory Oversight & the Food Industry
While caramel coloring is claimed to be safe by several international regulatory agencies, including the European Food Safety Authority (EFSA) and the US Food and Drug Administration (FDA), upper limit standards for ammonia-processed caramel colors exist, indicating concern over the health effects of 4-MeI. Furthermore, California became the first state to add 4-MeI to its list of “probable carcinogens” in 2011. In accordance with Proposition 65, manufacturer’s whose foods contained greater than 29ug—the “No Significant Risk Level”—were required to show the cancer risk warning label on appropriate products. State health officials estimated that exposure to 30ug/daily corresponded approximately to a 1:100,000 risk of developing cancer.
In response to California’s decisions—one that seeks to prevent exposure to unnecessary, controversial chemicals in everyday products—the food industry has publicly objected and called the National Toxicology Program findings into question. It has been suggested that manufacturers simply want to avoid the extra hassle of printing warning labels.
A January 2014 report out of Consumer Reports found that after testing as many as 81 soft-drinks from five different manufacturers in California and New York, samples of Pepsi One and Malta Goya contained 4-MeI levels in excess of 29ug/can. Samples taken from CA didn’t bear the state-mandated health warning label. Scientists from the National Toxicology Program and the Center for Science in the Public Interest (CSPI) urged the FDA to ban the use of ammonia-processed caramel colorings and, for the time being, accurately label foods that contain class III or IV colors. Three drink brands—Coke, Diet Coke, and Coke Zero—contained small amounts (less then 5ug) of the potential carcinogen, according to Consumer Reports.
Interestingly, after Pepsi had been informed of these findings, the soft-drink giant resorted to technicalities as its defense. Citing government consumption data, they claimed that individuals who drink diet soda typically drink 100 milliliters/day—less than one-third of the usual 12 oz. can. Then, there’s no fault in avoiding cancer-risk labels on products containing upwards of 29ug of 4-MeI, they argued. Goya, the other soft-drink manufacturer whose drinks were found to contain high levels of the compound, failed to respond to requests.
A Little Perspective
To put things into perspective, the CSPI claims that “ten teaspoons of obesity-causing sugars in a non-diet can of soda presents a greater health risk than the ammonia sulfite process caramel.” However, this coloring agent may still contribute to cancer development and should be avoided when possible. The FDA is currently conducting additional safety tests to ascertain the effects of 4-MeI before issuing a decision regarding its widespread use.
- Header Image: atalou (Flickr)
- Caramel Coloring: the Health Risk That May Be In Your Soda - Consumer Reports
- FDA Urged to Prohibit Carcinogenic "Caramel Coloring" - Center for Science in the Public Interest
- Caramel Coloring under European Law - Euro-Lex
- California Proposition 65 - Office of Environmental Health Hazard Assessment
- Toxicology and Carcinogenesis of 4-Methylimidazole in Animals - National Toxicology Program
- Caramel Coloring - DDW
- Petition to Bar the Use of Caramel Colorings Produced With Ammonia and Containing the Carcinogens 2-Methylimidazole and 4-Methylimidazole - Center for Science in the Public Interest