Cranberries Might Help Prevent Urinary Infections in Women

Evidence supports drinking cranberry juice — a familiar home remedy — to treat urinary tract infection (UTI), according to a new review from Scotland.

“UTIs can be distressing, and people often take a self-care approach rather than seeking professional advice,” said Ruth Jepson, a senior research fellow at the University of Stirling, who led the review. “It is a common problem that a great deal of health care time and resources are spent on.”

A diagnosis of a urinary tract infection refers to a presence of a large amount of bacteria in the urine that can cause pain during urination and can lead to more severe infections of the bladder and kidneys.

The aim of the systematic review was to determine whether taking cranberries is an effective way to prevent urinary tract infections.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

According to the American Urological Association, UTIs are among the most common medical conditions and are responsible for more than 7 million doctor office visits each year. The association reports that about 40 percent of women and 12 percent of men will experience at least one urinary tract infection during their lifetime.

People have used cranberries, especially cranberry juice, for decades to prevent and treat UTIs. The fruit contains organic substances, such as quinic acid and citric acid, which act as antibacterial agents to help eliminate bacteria from the bladder.

The Cochrane reviewers analyzed 10 studies including 1,049 participants of all ages who received either cranberry products (juice or cranberry capsules), placebo juice or water for at least one month.

Of the studies evaluated, there was no consistent dosage or concentration of cranberries given to the participants, but according to Jepson, there was a “typical amount” given daily.

“The most common amount recommended is one glass twice a day,” Jepson said. “Trouble is, there is no general rule as to how long you have to drink that much in order for you to prevent one UTI.”

Jepson and her colleague found that cranberry products significantly reduced UTIs over 12 months compared to the placebo/control groups. The cranberry treatment was more effective for women who suffered from recurrent UTIs. For example, in one study, after six months, eight women in the cranberry group had a least one recurring UTI, compared with 19 women in the lactobacillus group and 18 in the control group.

The Cochrane reviewers pointed to a high number of participant withdrawals within some of the studies, and suggested it was due to the taste of cranberry juice or the juice’s high cost. Jepson, however, could not recommend that a woman with recurrent UTI use cranberry capsules as an alternative treatment if taste or cost became prohibitive.