Citric Acid vs Silicon Dioxide: which is worse?

What is Citric Acid?

Citric acid is a weak organic acid naturally occurring in citrus fruits. Commercial citric acid is produced almost entirely by fermentation of sugar substrates (typically molasses or corn syrup) using the mold Aspergillus niger. It is the most widely used food acidulant and preservative globally, also functioning as a chelating agent and flavor enhancer.

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.

Documented risks

Citric Acid: Generally recognized as safe. Excessive consumption can erode tooth enamel due to its acidic nature — dentists recommend rinsing with water after consuming highly citric drinks. A 2018 report in the journal BMJ Case Reports described a cluster of inflammatory reactions (joint pain, muscle weakness) in individuals who reported reactions specifically to industrially produced citric acid, hypothesizing residual Aspergillus proteins from the fermentation process as a potential cause. This remains a hypothesis without controlled clinical evidence, and regulatory agencies maintain its safety status.

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.