Myth Busted - Cranberry juice proven ineffective against UTIs

Have you heard that Cranberry juice prevents or treats urinary tract infections (UTIs) and saves patients from seeing a doctor or taking antibiotics?

Cranberry juice or capsules is a widely used “natural” folk remedy to prevent UTIs or treat symptoms. Now a recent research study debunked cranberry juice as ineffective to treat these nasty and upsetting infections.

cranberry juiceUTIs are far more common in females than in males and postmenopausal women are especially at risk. Painful and frequent urination, blood in the urine and pelvic pain are most unpleasant and develop more commonly during hot summer months.

Bacteria that are natural in the gastrointestinal system can populate the pelvic regions and sometimes manage to ascend through the urethra into the bladder and further upwards into the kidneys where they can cause damage. Some women are more prone to UTIs than others and require antibiotic treatments regularly.

Wouldn’t it be great if drinking cranberry juice could prevent or even treat those symptoms?

The myth of the Cranberry juice started because cranberries have an active ingredient that could prevent adherence of E. coli bacteria (the main cause of UTIs) to cling to other bacteria and to the urinary tract.

Up to date there has been mixed evidence on the power of cranberry juice.

Laboratory studies have found that cranberry juice could help prevent E. coli and UTIs, but would not cure them. However in a 2012 review of 24 studies which was one of the largest to date found overall neither cranberry juice nor capsule supplements were effective in preventing UTIs.

The latest study involving elderly residents of a nursing home has been conducted at a very high scientific level and also suggests no benefit to drinking cranberry juice for treatment or curing UTIs. In fact, the study found no difference between patients treated with cranberry capsules or placebos. The current study, together with previous reports, provides considerable evidence that cranberry products do not prevent or relieve symptoms of UTIs in women.

The Latest study

The latest study randomly assigned 185 female nursing home residents over 65 years of age to one of two groups. People either had 2 cranberry capsules once a day (the equivalent of 591 ml) or they had 2 placebo capsules once a day.  Placebos are sham treatments, substances known to have no effect. Both groups took the tablets for one year, and were tested for a UTI (presence of bacteriuria plus pyuria) every 2 months. The average age of the women was 87 years and 31% had a UTI at time of enrolment.

Study Results

147 participants completed the study for the full one year. Overall adherence to taking the capsules was 80%. There was no difference among the two groups in the primary outcome of presence of bacteriuria with pyuria (29.1% in the cranberry group vs 29.0% in the placebo group). Also, there were no significant differences for those elderly women to develop a symptomatic urinary infection (10 episodes in the cranberry group vs 12 episodes in the placebo group).

Is it suspected the active ingredient in cranberry juice thought to help fight bacteria is diminished by the time it reaches the bladder.

Treatment for UTIs

For UTIs antibiotics is still the standard treatment. Cranberry juice may help with hydration however it will not help treat or cure a UTI. Beware that it is full of sugar and can be bad for teeth. Cranberry juice can be marketed as a “health” drink, but has similar levels of sugar as soft drink. Drink too many and this can cause you to increase your weight and risk of type 2 diabetes. A study concluded for every sugar-sweetened drink you have per day, there was an 18% increased risk of developing type 2 diabetes.

If you suspect you have a UTI visit your GP. An untreated UTI could potentially become a kidney infection if left untreated.

If you wish to receive regular information, tips, resources, reassurance and inspiration for up-to-date care, that is safe and sound and in line with latest research please subscribe here to receive my blog, or like Dr Andreas Obermair on Facebook. Should you find this article interesting, please feel free to share it. 

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  • Perlman Clinic Mira Mesa 08/08/2022 7:10pm (14 months ago)

    Thank you for sharing this informative article. I hope there are a lot of practitioners who could read this and be guided accordingly.

  • Patricia Kelly 08/12/2016 12:47pm (7 years ago)

    Well, damn it. Not only useless but full of sugar!
    Thanks for the information

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