A

merican cranberry (Vaccinium macrocarpon) is one of only three species of fruit native to North America. The other species are blueberry (Vaccinium angustifolia) and bil-berry (Vaccinium myrtillus). Cranberry typi-cally grows in bogs and is a member of the same family as blueberry and bilberry. Mas-sachusetts and Wisconsin are the main areas of present-day commercial production of cran-berry.1 The ripe fruit was used medicinally by Native Americans for the treatment of bladder and kidney ailments. Pilgrims called the fruit “craneberry ” because the stem and flower resembled the head, neck, and beak of a crane.1 Therapeutic applications of cranberries documented during the 17th century included the relief of blood disorders, stomach ailments, liver problems, vomiting, appetite loss, scurvy, and cancer.2 Before the advent of antibiotics, cranberry continued to be a popular treatment for urinary tract infections (UTIs).3 Pharmacology The mechanism of action of cranberry has prompted much scientific discussion. It was first hypothesized that acidification of the urine contributed to an antibacterial effect. The current proposed mechanism of action focuses primarily on cranberry’s ability to prevent bacterial binding to host cell surface membranes. In vitro studies have observed potent inhibition of bacterial adherence of Escherichia coli4 and other gram-negative uro-pathogens.5 Cranberry has been found to spe-cifically inhibit hemagglutination of E. coli by expression of types 1 and P adhesin6 through the component compounds fructose7 and proanthocyanidins.