Dimethylpolysiloxane vs Acesulfame Potassium: which is worse?

What is Dimethylpolysiloxane?

Dimethylpolysiloxane (PDMS, polydimethylsiloxane) is a silicone-based polymer used as an antifoaming agent in food and beverages. It prevents the formation of foam during food manufacturing and cooking. It is the same base material used in silicone cookware, medical devices, and contact lenses.

What is Acesulfame Potassium?

Acesulfame potassium (Ace-K) is a calorie-free synthetic sweetener approximately 200 times sweeter than sucrose. It contains a potassium atom bonded to an oxathiazinone dioxide ring structure. It is heat-stable and non-metabolized, passing through the body unchanged. Often blended with sucralose or aspartame to mask bitter aftertaste.

Documented risks

Dimethylpolysiloxane: Dimethylpolysiloxane is generally considered non-toxic. It is not absorbed by the gut and passes through the digestive system unchanged. The FDA permits it at up to 10 ppm in cooking oils. EFSA's evaluation found no evidence of toxicity at permitted food use levels. There are no established cancer or reproductive toxicity concerns with PDMS at food use concentrations. The compound is the same base polymer used in many safe medical applications including contact lenses and breast implants (though the medical grade is different purity). The main environmental concern is PDMS persistence in the environment, as it is not readily biodegradable. Primary consumer concern is psychological rather than toxicological: the fact that it is used in both McDonald's frying oil and Silly Putty (which also contains PDMS) generates public attention, but the chemistries are actually different grades of the same polymer family.

Acesulfame Potassium: The safety database for Ace-K is considered less comprehensive than that for other sweeteners. Critics have argued that the original FDA approval studies from the 1970s-1980s were insufficient in quality and length to definitively establish long-term safety. The Center for Science in the Public Interest (CSPI) has petitioned for additional testing. Two rat studies found statistically significant increases in lung tumors (in male rats) and mammary tumors at high doses. Regulatory agencies have argued these doses far exceeded typical human exposure and attributed the tumor findings to other factors. However, the question of whether Ace-K's approval studies meet modern standards has been raised by independent researchers. A 2021 study in Cell found that Ace-K and other non-nutritive sweeteners altered gut microbiome composition and affected glucose tolerance in some human participants. Ace-K specifically was associated with changes in gut bacteria that correlated with glycemic effects. Neurological concerns: some animal studies suggest Ace-K may affect brain neurotransmitter systems. A 2013 study in PLoS ONE found that Ace-K consumption in pregnant mice altered offspring postnatal taste preference and increased weight gain, suggesting potential transgenerational effects. These findings were at doses exceeding typical human intake. Endocrine disruption potential has been raised in some in vitro studies, but comprehensive human data are lacking.