More not-great news for soda manufacturers, on the heels of last week's study concluding that daily diet soda drinkers have elevated risk of strokes: Consumer nutrition advocate group the Center for Science in the Public Interest has petitioned the Food and Drug Administration to ban use of certain types of "caramel coloring" in colas and various foods.
According to CSPI, the brown coloring at issue is made by reacting sugars with ammonia and sulfites under high pressure and temperatures, and these chemical reactions result in formation of 2-methylimidazole (2-MEI) and 4-methylimidazole (4-MEI), which have been shown in government-conducted studies to cause lung, liver or thyroid cancer or leukemia in lab mice/rats.
Specifically, CSPI cites the conclusion of the National Toxicology Program (a division of the National Institute of Environmental Health Sciences) that there is "clear evidence" that 2-MI and 4-MI (also termed 4-MEI) are animal carcinogens. CSPI further states that chemicals that are animal carcinogens are "considered to pose cancer threats to humans," and reports that University of California, Davis researchers found "significant levels" of 4-MI in five brands of cola.
Federal regulations distinguish among four types of caramel coloring -- two of which are produced with ammonia and two without it, according to CSPI. The group wants the FDA to prohibit the two made with ammonia. These are Caramel IV, or ammonia sulfite process caramel, which CSPI identifies as the type used in colas and other dark soft drinks; and Caramel III, which CSPI reports is produced with ammonia but not sulfites and is sometimes used in beer, soy sauce and other foods.
CSPI's call for banning use of these caramel colorings was joined by "five prominent experts on animal carcinogenesis (including some with current or past affiliations to the National Toxicology Program), who sent a letter to FDA Commissioner Margaret Hamburg stating in part that "the American public should not be exposed to any cancer risk whatsoever as a result of consuming such chemicals, especially when they serve a non-essential, cosmetic purpose."
CSPI also reports that California's Proposition 65, if finalized, would add 4-MI to the state's list of "chemicals known to the state to cause cancer" and would require foods/beverages containing more than specific levels of these chemicals to carry warning labels. The maximum level for 4-MI would be 16 micrograms per person per day from an individual product, and popular brands of cola contain about 200 micrograms of 4-MI per 20-ounce bottle, the group reports.
"Many people, especially teenaged boys, consume more than that each day" and, therefore, if passed, Prop 65 would mean that Coke, Pepsi and other soft drinks would be required to bear a cancer warning label, states CSPI.
The Grocery Manufacturers Association issued a prompt response statement:
"Ensuring the safety of our products -- and maintaining the confidence of consumers -- is the single most important goal of our industry. Product safety is the foundation of consumer trust, and our industry devotes enormous resources to ensure that our products are safe. Our companies continuously review and monitor all emerging science and scientific studies and incorporate these as warranted into our manufacturing practices to help ensure that we are always producing the safest possible product for our consumers.
"4-MEI is found in trace amounts in a wide variety of foods and beverages. There is no evidence that 4-MEI causes cancer or poses any other health risks to humans. In addition, no health regulatory agency around the globe, including the FDA, has said that 4-MEI is a known human carcinogen."