Silicon Dioxide vs Ascorbic Acid: which is worse?

What is Silicon Dioxide?

Silicon dioxide (silica) is a naturally occurring mineral compound used as an anti-caking agent in powdered and granular foods. The food-grade form is amorphous (non-crystalline) synthetic silica, distinct from the crystalline quartz form associated with lung disease. It absorbs moisture and prevents clumping in powders.

What is Ascorbic Acid?

Ascorbic acid is the chemical name for vitamin C, an essential water-soluble vitamin found abundantly in fruits and vegetables. As a food additive (E300), it functions as an antioxidant preservative, preventing oxidative browning and rancidity. Commercial ascorbic acid is produced by fermentation of glucose, most commonly from corn.

Documented risks

Silicon Dioxide: Food-grade amorphous silicon dioxide is generally recognized as safe. EFSA re-evaluated it in 2018 and concluded there was no safety concern at typical dietary exposure levels; however, the panel noted uncertainty about nanoparticle forms. The food form should not be confused with crystalline silica (quartz) dust, which is a recognized carcinogen when inhaled occupationally. Ingested amorphous silica passes through the body largely unabsorbed.

Ascorbic Acid: Generally recognized as safe. Note: when ascorbic acid is combined with sodium benzoate or benzoic acid in acidic beverages, benzene can form — a Class 1 carcinogen. This combination should be avoided in formulations. As a standalone additive, ascorbic acid is not only safe but nutritionally beneficial. Very high supplemental doses (>2 g/day) can cause diarrhea and kidney stone risk in predisposed individuals.