Cranberry Studied in Urinary Tract Health

By VRP Staff

A recently published study investigated the dosage at which cranberry (Vaccinium macrocarpon) is most effective in protecting urinary tract health. The National Institutes of Health (NIH) report that urinary tract infections are the second most common type of infections, affecting approximately 13.3 percent of women and 2.3 percent of men each year. In addition, according to the NIH, urinary tract infections account for an estimated 8.3 million doctor visits annually.

The most common cause of urinary tract infections is the bacterium Escherichia coli (E. coli), which is normally found in the colon. E. coli adheres to the cells in the urinary tract, causing infection. The proanthocyanidins found in cranberry have been shown to reduce the ability of E. coli to adhere to the cells in the urinary tract.

In this new, randomized, double-blind, placebo-controlled study, urine samples were evaluated from 32 subjects after ingestion of cranberry or placebo. The results showed that cranberry supplementation significantly inhibited the ability of E. coli to adhere to the epithelial cells in the urinary tract compared to placebo. Furthermore, the researchers showed that this effect was dose-dependent, meaning increasing dosages led to increased bacterial adhesion inhibition. The study found that 72 mg of cranberry proanthocyanidins both increased and prolonged (24 hour) the anti-adhesion effect. In addition, the study showed that the bacterium that had grown in the urine samples from the subjects who had ingested the cranberry supplement had decreased virulence.

The researchers concluded that cranberry extract “may offer some protection against bacterial adhesion and virulence in the urinary tract. This effect may offer a nyctohemeral [day and night] protection.”

Reference:

L, Matsumoto T, Tenke P, Sotto A, Lavigne JP. Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study. BMC Infect Dis. 2010 Apr 14;10:94.

Cranberry extract is found in D-Mannose Plus.