Cranberries reduce Urinary Tract Infection

In a meta analysis of 13 randomised trials published in Arch Int Med (2012) the authors showed that Cranberry products probably do help prevent urinary tract infections. A significant effect emerged from pooled analyses that excluded one outlying trial (risk ratio 0.62, 95% CI 0.49 to 0.80), confirming results from a previous much smaller meta-analysis. The effect is greatest for individuals taking more than 2 doses per day, younger women and children. The effect is less strong for the elderly, pregnant and patients with neuropathic bladder dysfunction. Cranberries (genus Vaccinium) have been used as a natural remedy for at least 100 years, and in the 1980s scientists discovered that the berries contain an active ingredient (possibly proanthocyanidins) that stops bacteria sticking to uroepithelial cells.
In a separate report published as a Cochraine review (2012) the researchers concluded that current evidence did not support a preventative role for cranberry juice.