64: Variability of commercial cranberry products for the prevention of uropathogenic bacterial adhesion


      Cranberry has been known to reduce the number of urinary tract infections. Research suggests that the proanthocyanidins (PACs) in cranberry fruit actively prevent bacterial adhesion to the bladder wall, thereby preventing infection. We sought to measure the levels of PACs in commercially available cranberry products.

      Materials and Methods

      Seven cranberry products were tested for bacterial anti-adhesion activity using a hemagglutination assay specific for P-fimbriated Escherichia coli. PACs were isolated using the gravimetric technique (C-18 followed by Sephadex LH-20 solid phase chromatography) to determine levels in each product and tested for anti-adhesion activity on an equal weight basis (starting concentration of 5 mg/mL).


      Whole products anti-adhesion activity ranged from 0.47 to 60 mg/mL. PAC levels ranged from 0.56 to 175 mg/g. Whole product anti-adhesion activity for four of the products was not able to be detected. See Table 1.


      There is a large amount of variability in the amount and bioactivity of PACs in commercially available cranberry product. In addition, there were several products that contained virtually no active component of cranberry.
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