Dimethylpolysiloxane vs Xanthan Gum: 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 Xanthan Gum?

Xanthan gum is a polysaccharide produced by fermentation of sugars by the bacterium Xanthomonas campestris. It is a white to off-white powder that dissolves in cold or hot water to form a viscous gel. It is widely used as a thickener and stabilizer and is a key ingredient in gluten-free baking.

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.

Xanthan Gum: Generally recognized as safe by both FDA and EFSA. At high doses, xanthan gum can have laxative effects due to its fermentable fiber content, producing gas and bloating in some individuals. A 2011 case report in the journal Pediatrics raised concerns about xanthan gum in infant formula (as 'Simply Thick') being associated with necrotizing enterocolitis; the FDA subsequently advised against its use in premature infants. For healthy adults consuming normal food amounts, it poses no significant health risk.