Benzoic Acid vs Guar Gum: which is worse?

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.

What is Guar Gum?

Guar gum is a galactomannan polysaccharide extracted from guar beans (Cyamopsis tetragonoloba), grown primarily in India and Pakistan. It is a highly effective thickener — approximately 8 times more powerful than cornstarch — and functions as a dietary fiber. It is used extensively in food, pharmaceutical, and industrial applications.

Documented risks

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.

Guar Gum: Generally recognized as safe. At high doses (e.g., dietary supplement doses of 10–20 g/day), guar gum can cause flatulence, bloating, and diarrhea. Historically, concentrated guar gum dietary supplements were associated with esophageal obstruction, prompting the FDA to ban such supplements in 1992. At typical food additive use levels, no significant safety concerns have been identified. EFSA confirmed its safety as a food additive in 2017.