Urinary excretion of hippuric acid after consumption of nonalcoholic beverages

To investigate the types and quantities of beverages that increase urinary hippuric acid (HA) excretion, the authors recruited 137 healthy medical students and divided them into quintiles according to consumption of benzoic acid (BA) in beverages. Using chromatography, urinary HA before and 1.5 hours and 3 hours after consumption of various beverages and BA consumption in the beverages were measured. The mean age of the group was 24.2 years; 21 were female. The range of BA in 13 beverages was 0-1.02 mg/mL. The geometric means of urinary HA before consuming them in five groups were 0.276, 0.270, 0.207, 0.262, and 0.316 g/L, respectively (p = 0. 567); 1.5 hours after consuming the beverages, they were 0.210, 0. 603, 1.026, 1.066, and 1.688 g/L, respectively, and significantly increased after adjustment for urinary HA before ingestion (p < 0. 001). Three hours after ingestion, the geometric means were 0.160, 0. 232, 0.306, 0.287, and 0.337 g/L, respectively (p < 0.001). The authors estimate that beverages that contain more than 100 mg BA could increase urinary HA excretion significantly, up to 1.12 g/L without toluene exposure. Checking dietary and beverage-intake histories is essential in the interpretation of urinary HA concentrations in population studies.