Reduction of Bacteriuria and Pyuria Using Cranberry Juice-Reply

In Reply. —Dr Hamilton-Miller raises an interesting mechanistic question. However, similarly high concentrations of quinic acid were added to the placebo beverage to mimic the taste of cranberries, making this explanation less likely. Moreover, benzoate is very widespread as a preservative in common foods, occurring in higher concentrations in soft drinks (170 to 420 ppm) than in standard cranberry-based beverages (40 to 50 ppm). The pKaof all these organic acids is about 4, so they would exist in a predominantly ionized state at the pH of urine. If the effect of cranberry juice on bacteriuria is real, a likelier mechanism may be the inhibition of bacterial adherence to the mucosal surface.1 We agree with Dr Goodfriend that catheterized urine specimens represent a criterion standard. However, by using careful technique, we succeeded in obtaining samples without bacteriuria (using the standard definition) in about three fourths of all samples,