Sorbitol vs Benzoic Acid: which is worse?

What is Sorbitol?

Sorbitol is a sugar alcohol (polyol) naturally found in some fruits, including apples, pears, and prunes. Commercially, it is produced by hydrogenation of glucose. It has approximately 60% of the sweetness of sucrose but provides fewer calories (2.6 kcal/g vs 4 kcal/g for sugar) and does not cause a significant immediate insulin response.

What is Benzoic Acid?

Benzoic acid is a naturally occurring aromatic carboxylic acid found in cranberries, prunes, cinnamon, and many berries. It is used as a preservative against bacteria, yeast, and fungi at pH below 4.5. In the body, benzoic acid is conjugated with glycine to form hippuric acid, which is excreted in urine.

Documented risks

Sorbitol: At doses above 20–50 g/day, sorbitol can cause osmotic diarrhea because it is incompletely absorbed in the small intestine and is fermented by colonic bacteria. EU regulations require products containing more than 10% added polyols to carry the label 'excessive consumption may produce laxative effects.' This is well-known and predictable. Sorbitol is not carcinogenic and does not raise blood glucose significantly, making it suitable for diabetics in controlled amounts.

Benzoic Acid: When benzoic acid (or sodium benzoate) is combined with ascorbic acid (vitamin C) in beverages, it can form benzene, a known carcinogen classified as Group 1 by IARC. This reaction is promoted by heat and light. The FDA and EFSA monitor benzene levels in beverages and have set informal guidance limits. A 1999 Lancet publication and the subsequent 2007 'Southampton study' did not directly involve benzoic acid, but sodium benzoate was included in the tested mixture. Some individuals with aspirin sensitivity may react to benzoic acid. The ADI is 5 mg/kg body weight/day.