Advantame vs Caramel Color IV: which is worse?

What is Advantame?

Advantame is the newest FDA-approved synthetic sweetener, approved in 2014. Like neotame, it is a structural derivative of aspartame but with a vanillin-derived substituent. It is approximately 20,000 times sweeter than sucrose — the most potent sweetener currently approved for food use in the US.

What is Caramel Color IV?

Caramel Color IV (Class IV caramel, E150d) is a food coloring made by heating sugar with both ammonium and sulfite compounds. This production method creates a unique set of reactive byproducts, notably 4-methylimidazole (4-MEI), which has been linked to cancer in animal studies. It is the most widely used caramel coloring in beverages like Coca-Cola and Pepsi.

Documented risks

Advantame: Advantame is the newest approved high-intensity sweetener with the least post-approval safety data. The FDA approval was based on extensive pre-market animal studies showing no significant toxicity, carcinogenicity, reproductive toxicity, or neurotoxicity at relevant doses. EFSA approved it for EU use in 2014, finding no safety concerns based on the submitted data. Like other synthetic sweeteners, advantame has not been studied for long-term effects in large human populations post-approval. The same gut microbiome and glucose tolerance concerns raised for other sweeteners (aspartame, sucralose, acesulfame K) have not been specifically studied for advantame, though the class-wide concerns are relevant. Given its 2014 approval date, independent long-term safety studies are still limited.

Caramel Color IV: The primary concern with Caramel Color IV is 4-methylimidazole (4-MEI), a byproduct of the ammonia-sulfite caramel production process. The National Toxicology Program (NTP) found that 4-MEI caused lung cancer in male and female mice at high doses in 2-year bioassay studies, leading to California listing 4-MEI as a known carcinogen under Proposition 65 in 2011. The Prop 65 safe harbor level is 29 micrograms 4-MEI per day (the level that would cause 1 additional cancer per 100,000 people over a 70-year lifetime). CSPI testing in 2011-2012 found Coca-Cola and Pepsi sold in California contained 4-MEI levels that, at typical consumption rates, would exceed this threshold — triggering voluntary reformulation by both companies to reduce 4-MEI in their US products. The FDA reviewed 4-MEI and concluded that typical exposure levels 'are not a safety concern.' EFSA's evaluation found the NTP findings concerning but noted the margin of safety at typical European exposure levels. The cancer mechanism in mice involves high doses that may not extrapolate to typical human cola consumption.