Cranberry juice may not be as effective against urinary tract infections as previously thought, according to a U.S. study published in the journal of Clinical Infectious Diseases.
Researchers worked with 319 female college students who presented with an acute UTI. Volunteers in the double-blind study were given either cranberry juice or a similar-tasting placebo, and asked to consume two glasses a day.
Surprisingly, those who drank the cranberry juice showed a higher likelihood of recurrence, with 20 percent suffering a second UTI within six months versus 14 percent of those on the placebo.
Those who drank either juice, however, were only half as likely to suffer a recurrence when compared with regular outcomes. The researchers hypothesize that this could be due to the vitamin C contained in both juices, or simply because the women were better hydrated. A 2008 study showed that vitamin C levels were lower in blood tests of those suffering a UTI.
These new findings contradict previous studies. Since 2008, at least four clinical trials have found cranberry juice to be effective in preventing UTIs.