McMurdo et al. Of the patients in the placebo group, 7. In a six month trial, Avorn et al. Therefore, the evidence to recommend cranberries for UTI prevention in the elderly is inconclusive.
To evaluate UTIs and lower urinary tract symptoms in male and female patients undergoing radiotherapy treatment for bladder or cervical cancer, cranberry juice was administered twice daily for six weeks in a randomized, double-blind, placebo-controlled trial. There was no statistical difference between the groups for the incidence of UTIs Cranberries have been compared with trimethoprim for UTI prevention in a randomized, controlled study in women older than 45 One study evaluated the use of cranberry juice to prevent UTIs during pregnancy There were four UTIs and 23 cases of asymptomatic bacteriuria, but there was no significant difference with regard to the numbers of UTIs between the groups.
Compliance and tolerability were considerable obstacles in this study. Of the subjects, There are several trials for patients with neurogenic bladder and under intermittent catheterization IC. The follow-up at six months did not determine a significantly longer UTI-free period in any of the regimens McGuiness et al. One study by Hess et al. They randomized patients with spinal cord injuries into two groups i.
After six months, the patients alternated groups for six more months. For patients with IC, two randomized trials have been published, both in adults with spinal cord injuries. One study had 74 participants divided in two groups receiving either 2 g of cranberries or placebo. No differences were observed in pyuria, bacteriuria, or episodes of symptomatic UTIs No statistically significant protective effect was observed for cranberry consumption in this population In pediatric populations, there are two studies concerning children with neurogenic bladder under IC.
Foda et al. No statistical difference was observed. In another study, 15 children were randomized into two groups that received either cranberries or placebo for three months and then crossed over. No statistical differences were observed for bacteriuria or UTIs Ferrara et al. Over this time period, they observed UTIs in The recommended doses of cranberry products for the prevention of UTIs have been poorly defined, and beverage formulations vary widely.
An ex vivo study examining human urine following cranberry juice cocktail consumption suggests that twice-daily dosages of cranberries 36 mg of PAC might offer additional protection during a 24 h period 25 , It is important to consider that dried cranberry extract can be broken down by exposure to light, heat or cold.
However, the addition of vitamins C and E exert a stabilizing influence Reasons for dropout included: pregnancy, unrelated infections requiring antibiotic therapy, moving from the area, and gastrointestinal symptoms. In children in particular, taste was the main reason for stopping therapy Other important issues are the cost and the necessity to carry large amounts of cranberry juice that may limit acceptance in general population. Caloric load in some formulations was also the cause of some withdrawals.
This could indicate that cranberry juice is not an acceptable therapy over a long time period. Side effects commonly reported include the following: reflux, mild nausea, frequent bowel movements, headaches, elevation in blood glucose levels, and a cutaneous reaction.
There are some concerns about the potential for cranberries to cause thrombocytopenia and nephrolithiasis 58 , There is one report of immune-mediated thrombocytopenia after the ingestion of an unknown amount of cranberry juice.
Four studies evaluated the potential risk for lithiasis 60 - 63 ; however, none have shown an increased risk, though some reported elevated oxalate in the urine that could potentially enhance the risk for oxalate stones. Nonetheless, another study described a protective effect after cranberry usage, an increase in citrate excretion and a reduction in oxalate excretion.
Flavonoids, the major constituent of cranberries, have an established effect on the cytochrome P CYP drug-metabolizing enzyme. Flavonoids are also aromatase inhibitors, which are crucial enzymes in estrogen biosynthesis.
There are some reports of interactions between cranberry juice and warfarin 65 , Increases in the international normalized ratio INR of prothrombin time values were reported in these patients; one patient died as a result of gastrointestinal and pericardial hemorrhage Potential mechanisms of this interaction have included the salicylate content of the juice 68 and the presence of CYP enzyme-inhibiting flavonoids.
There are other studies suggesting that the potential interaction is low; however, the dosage was low ml of juice daily. A placebo-controlled study using volunteers found that cranberries increased sensitivity to the dynamic effects of warfarin. However, a systematic evaluation of in vitro and in vivo interactions determined that cranberries could inhibit warfarin hydroxylation in vitro , but cranberry juice had no effect on warfarin clearance in vivo. This lack of concordance reflects the fact that the site of warfarin metabolism liver is different from the site of exposure to the inhibitory components in the cranberry juice intestine Aside from these data, the effect of purified PAC on drug metabolism is unknown.
There are many discrepancies in the published data that make comparisons difficult, including the type of cranberry product used, the amount of cranberry ingested, the type of subjects and comorbidities.
In vitro studies suggest a possible effect of PAC, the active compound in cranberries that inhibits the adhesion of p-fimbriated bacteria, mainly E. Similar effects on activity in vivo are not found in the literature. In , the Cochrane review supported cranberry potential use only in recurrent UTI prophylaxis for young women. Even for this indication, further clinical trials double-blinded, randomized, placebo-controlled displayed no differences between cranberry consumption and controls.
The efficacies in other groups of subjects, such as the elderly or pediatric populations with neurogenic bladder, are even more questionable. Patient withdrawal rates in studies are high due to cost, taste and gastrointestinal intolerance. However, patients should be aware of drug interactions mainly warfarin that may even have potentially fatal consequences.
Using the current available data, the use of cranberries cannot be scientifically promoted for UTI prevention. Future studies should focus on PAC, the active compound in cranberries, instead of the whole fruit. No potential conflict of interest was reported. National Center for Biotechnology Information , U. Journal List Clinics Sao Paulo v. Clinics Sao Paulo. Find articles by Marcelo Hisano. Find articles by Homero Bruschini. Find articles by Antonio Carlos Nicodemo. Find articles by Miguel Srougi.
Author information Article notes Copyright and License information Disclaimer. E-mail: rb. This article has been cited by other articles in PMC. Abstract Lower urinary tract infections are very common diseases. Table 1 In vitro activity of cranberries against bacteria. Lee et al. In vitro urine activity after cranberry consumption in volunteers mg of whole, dry cranberries and 25 mg of concentrated, dry cranberries E. Virulence reduction when E. Gupta et al. Tampons can keep the area dryer, leaving less of a chance for bacteria to flourish and cutting down on the risk of infection.
While your bathing suit alone cannot cause a UTI, wearing a wet bathing suit for a prolonged period of time can create a breeding ground for bacteria. Make sure to change out of your wet clothes as soon as you are finished swimming to reduce your risk.
Women definitely get UTIs more often than men. This is because the urethra, the duct that carries urine out of the body, is shorter in women, allowing bacteria to more easily reach the bladder.
However, this is still a myth, as men can and do get UTIs. UTIs are more common in men who have not been circumcised and suffer from other medical issues including incontinence, prostate cancer or urinary tract stones. Another surprising fact is that children can also get UTIs. Uncircumcised boys younger than 3 months old and girls younger than 12 are at the highest risk for contracting UTIs during their childhoods. Moore notes. The bottom line? Moore says.
None of these beliefs is supported by scientific data, she says. On the other hand, here are three things that Dr. Moore says women should do to help prevent UTIs:. What is OCD and what can you do about it? View What is OCD and what can you do about it?
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