Lactic Acid vs Calcium Propionate: which is worse?

What is Lactic Acid?

Lactic acid is an organic acid naturally produced during fermentation of carbohydrates by lactic acid bacteria. It gives fermented foods such as yogurt, cheese, and sauerkraut their characteristic tangy flavor. Commercial lactic acid used in food is produced by bacterial fermentation of glucose or lactose, or in some cases by chemical synthesis.

What is Calcium Propionate?

Calcium propionate is the calcium salt of propionic acid, a short-chain fatty acid naturally produced during fermentation. It is one of the most widely used mold inhibitors in commercial bread and baked goods. It works by penetrating fungal cells and lowering internal pH to inhibit growth.

Documented risks

Lactic Acid: Lactic acid is a normal byproduct of human metabolism (produced during anaerobic exercise). It is generally recognized as safe at food additive levels. Excessive consumption of foods acidified with lactic acid could theoretically contribute to dental erosion, as with all acidulants. For individuals with rare inborn errors of lactate metabolism, dietary lactic acid may require monitoring.

Calcium Propionate: Generally recognized as safe. However, a 2012 study in the Journal of Pediatric Child Health (Dengate & Ruben) and a 2019 study published in Science Translational Medicine found that calcium propionate induced insulin resistance in a mouse model and raised metabolic concerns. The 2019 animal study, conducted by Bhatt et al., found that propionate triggered glucagon and norepinephrine secretion. Some open-label human studies and parental reports have linked calcium propionate to irritability, sleep disturbance, and behavioral changes in sensitive children, though these lack robust clinical trial evidence. Most regulatory agencies consider it safe at current use levels.