Polydextrose vs Citric Acid: which is worse?

What is Polydextrose?

Polydextrose is a synthetic polymer of glucose (with some sorbitol and citric acid) created under heat and vacuum conditions. It functions as a soluble dietary fiber, providing only 1 kcal/g. It is used to add bulk to reduced-calorie foods while also contributing fiber content. The FDA approved it as GRAS in 1981.

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.

Documented risks

Polydextrose: At doses above ~90 g/day, polydextrose can cause flatulence, bloating, and loose stools. At normal food use levels it is well tolerated. EFSA confirmed its safety in 2012. It functions as a soluble prebiotic fiber, feeding beneficial gut bacteria. No genotoxicity, carcinogenicity, or reproductive toxicity has been identified.

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.