Cranberries or cranberry juice has often been recommended as a way to help prevent urinary tract infections (UTIs). But, a new study shows the fruit may not be as effective against the infection as once thought.
A review of recent studies showed that taking or consuming cranberry products only have small health benefits for women, and only in women who have recurrent UTIs.
"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," ," lead researcher Ruth Jepson of the University of Stirling in Stirling, Scotland said in a press release. "More studies of other cranberry products such as tablets and capsules may be justified, but only for women with recurrent UTIs, and only if these products contain the recommended amount of active ingredient."
UTIs are infections along the urinary tract, which can include the bladder, kidneys, ureters or urethra. Symptoms include cloudy or bloody urine which may have an odor, low fever, pain or burning with urination, pressure or cramping in the lower abdomen or the need to urinate often even if you just went.
Diabetes, older age, problems emptying your bladder, urinary catheters, bowel incontinence, enlarged prostates or anything that blocks to the flow of urine, kidney stones, pregnancy, surgery of the urinary tract and staying still for long period of time may increase risks of developing an infection.
Researchers looked at 24 studies that involved a total of 4,473 people, including 14 additional studies from the last time they had investigated the topic in 2008. Subjects had taken cranberry juice, tablets or capsules, while those in control groups were given placebo cranberry products, water, methenamine hippurate (Urex), antibiotics, lactobacillus (acidophilus) or nothing. The goal in all the studies was to look at the effect of cranberries on preventing UTIs.
While some studies did show that cranberries did help women who had recurrent UTIs, they still had to consume two glasses of cranberry juice daily to stop one infection. Women were shown to have a 14 percent lower risk of UTI, but researchers said that the number was not significant and may be due to chance.
"It's unlikely to be effective because it's very difficult for people to drink cranberry juice twice a day," Jepson told WebMD. "It's quite a commitment."
Dr. Suzanne Geerlings, infectious disease specialist at the Academic Medical Center in Amsterdam, Netherlands, said that people should continue to take cranberry products if they think it helps them, however.
"One major advantage of cranberry pills is that they don't lead to resistance of bacteria," Geerlings told WebMD.
Part of the problem, she pointed out, is that no one has figured out the exact dosage of cranberries necessary to prevent infection so there may be some benefit after all if the right amount to take is determined.
The study was published in The Cochrane Library on Oct. 17.