Cranberry juice offers little protection against urinary tract infections (UTIs) and cystitis, says a new study published in The Cochrane Library.
Cranberries and cranberry juice have been widely used for several decades as a way to prevent UTIs including bladder infections and cystitis. A recent study published in the Journal of Urology even concluded that children who drank cranberry juice high in proanthocyanidins (PACs) have two-thirds fewer urinary tract infections.
One theory behind the use of cranberry juice in preventing UTIs, which was presented at a 2010 meeting of the American Chemical Society, is that certain sugars and flavanol compounds found in cranberries prohibit bacteria from sticking to cells that line the urinary tract.
However, a new review led by Dr. Ruth Jepson of the University of Stirling concluded that “cranberry juice is significantly less beneficial than previous research has stated.”
For the review, the researchers looked at data from 24 studies that included a total of 4,473 participants. The test groups were given cranberry juice, cranberry capsules, or cranberry tablets. The participants in the control groups were given placebo cranberry products, methenamine hippurate, antibiotics, lactobacillus, water, or nothing.
The review concluded that, although there was a “small trend towards fewer UTIs in people taking cranberry product compared to placebo or no treatment,” the results were not significant. In other words, cranberry juice is not as effective in preventing urinary tract infections as previously thought.
As reported by Medical News Today, Dr. Jepson explains the findings:
“In the studies where participants were given juice, there were large numbers of drop-outs, suggesting it might not be easy to drink over long time periods. A common problem with studies evaluating cranberry tablets or capsules was that they rarely reported the amount of active ingredient, so it was unclear whether levels would have been high enough to have any effect.”
Dr. Jepson also does not recommend additional studies on the benefits of cranberry juice, stating that the results are pretty clear:
“We can’t see a particular need for more studies of the effect of cranberry juice, as the majority of existing studies indicate that the benefit is small at best, and the studies have high drop-out rates.”
Instead, a more effective way to prevent UTIs is to practice good hygiene, to drink plenty of water, and to fully empty the bladder regularly. Dr Helen Stokes-Lampard, a GP in Lichfield with a special interest in women’s health, sums up the findings of the most recent review on cranberry juice:
“Patients shouldn’t have unrealistic expectations about cranberry juice, but the research didn’t show there is any harm in drinking it, so if you feel it helps, there is no reason to stop. Medical evidence is evolving as more research emerges. Next year, there may be another study – and the pendulum may swing the other way.”
Will you continue drinking cranberry juice as a preventative measure against UTIs and cystitis?