UTIs are not prevented by consuming cranberry products, says study

For many years cranberries were thought to provide protective qualities against certain bacterial illnesses, however recent studies have shown otherwise.

It was believed that cranberries contain specific sugars and flavanol compounds that stop bacteria from attaching to cells coating the walls of the urinary tract. This has now been disproved by scientists.

Cystitis and other urinary tract infections cannot be prevented by cranberry drinks, tablets or capsules, say researchers.

Although there may be some minor benefit for females who experience recurring urinary tract infections (UTIs), according to the results from the University of Stirling. 

In all, evidence was collected from 24 studies involving 4,473 participants by Dr Ruth Jepson and her team from the university.

People in treatment groups were given cranberry tablets, juice or capsules. Those in control groups were given placebo cranberry products, methenamine hippurate, lactobacillus, antibiotics, water or nothing at all.

"The results suggest that cranberry juice is even less effective at preventing UTIs than was shown in our previous research," stated Dr Jepson.

The doctor explains that many participants who were given juice, dropped out of the study – which suggested that it may not be such an easy beverage to drink over extended periods of time.

Another problem associated with the cranberry tablets or capsules was that they rarely reported the amount of ingredient that was active.

This obfuscated the results as it was unclear whether levels would have been high enough to have any effect, if at all.

However in some studies there were small benefits for women suffering from recurring infections. It was found that women would have to drink two glasses of cranberry juice a day for extended periods to prevent an infection.

Therefore the researchers concluded that presently, there is not enough evidence to support the theory that consuming cranberry juice will prevent UTIs.

"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," said the doctor.

Posted by Neil Clark