Chemical Cuisine Rating

Avoid

Purpose: Artificial Sweetener

Health Concerns: Cancer, Hormone Disruption, Risks to Pregnant People

Found in: "Diet," "no sugar added," "sugar-free," and other products, including soft drinks, drink mixes, baked goods, gelatin desserts, frozen desserts, yogurt, candy, chewing gum, packaged (tabletop) sweeteners

This artificial sweetener is widely used around the world. It is about 200 times sweeter than sugar. In the United States, for several years acesulfame K (also called ace-K; the K is the chemical symbol for potassium) was permitted only in foods like sugar-free baked goods, chewing gum, and gelatin desserts. In July 1998, the FDA allowed this chemical in soft drinks, thereby greatly increasing its use and consumer exposure. It is often used together with sucralose or aspartame.

The safety tests of ace-K were conducted in the 1970s and were of mediocre quality. Key rat tests used animals afflicted by disease; a mouse study was several months too brief and did not expose animals during gestation. Two rat studies suggested that the additive might cause cancer. It was for those reasons that in 1996 the Center for Science in the Public Interest urged the FDA to require better testing before permitting ace-K in soft drinks. In addition, large doses of acetoacetamide, a breakdown product of ace-K, have been shown to affect the thyroid in rats, rabbits, and dogs. 

A small study of 20 lactating women, 14 of whom reported using artificial sweeteners generally, and nine of whom reported using acesulfame K, found that ace-K was the most commonly found artificial sweetener in breast milk. The breast milk of 13 of the women—including some who reported no intake of artificial sweeteners--contained acesulfame K. Pregnant and nursing women may want to make a special effort to avoid ace-K and other artificial sweeteners.

FDA should require manufacturers to conduct high-quality, modern-day studies of acesulfame potassium or withdraw its approval of it.

See our comprehensive Chemical Cuisine ratings of more than 150 food ingredients and additives.