Cranberries for preventing urinary tract infections

Abstract

BACKGROUND: Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). This is the third update of our review first published in 1998 and updated in 2004 and 2008 There was no significant difference between gastrointestinal adverse effects from cranberry product compared to those of placebo/no treatment (RR 0.83, 95% CI 0.31 to 2.27). Many studies reported low compliance and high withdrawal/dropout problems which they attributed to palatability/acceptability of the products, primarily the cranberry juice. Most studies of other cranberry products (tablets and capsules) did not report how much of the 'active' ingredient the product contained, and therefore the products may not have had enough potency to be effective. AUTHORS' CONCLUSIONS: Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated. Although some of small studies demonstrated a small benefit for women with recurrent UTIs, there were no statistically significant differences when the results of a much larger study were included. Cranberry products were not significantly different to antibiotics for preventing UTIs in three small studies. Given the large number of dropouts/withdrawals from studies (mainly attributed to the acceptability of consuming cranberry products particularly juice, over long periods), and the evidence that the benefit for preventing UTI is small, cranberry juice cannot currently be recommended for the prevention of UTIs. Other preparations (such as powders) need to be quantified using standardised methods to ensure the potency, and contain enough of the 'active' ingredient, before being evaluated in clinical studies or recommended for use. COMMENTSCranberry juice has been consumed as a treatment by women suffering from recurrent urinary tract infection over the last two decades. This practice began in the United States, and most of the supplies came from there since cranberries are not available in Brazil. 1 I have been informed about this by my patients, over the last 10 years. My personal experience with patients is that some relief of symptoms has been seen but that there have not been any proven results with regard to recurrent urinary tract infection. Notable relief of symptoms has been reported especially by women with interstitial cystitis. However, both the dosage used and the duration of cranberry juice consumption in these treatments are totally aleatory.

Recurrent Urinary Tract Infections Management in Women : A Review = الإلتهابات المتكررة للمسالك البولية عند النساء و طرق علاجها : مراجعة

“…65,66 Although earlier, smaller studies have shown that consuming cranberry juice or tablets can prevent RUTIs, an updated Cochrane review showed that evidence for its benefit in preventing UTIs is small; therefore, cranberry juice cannot be recommended any longer for UTI prevention. 21,[67][68][69] a c u p u n c t u r e Recent studies indicate that the rate of cystitis among cystitis-prone women treated with acupuncture was one-third the rate of that among untreated women and half the rate among women treated by sham acupuncture. Therefore, acupuncture may prevent RUTIs in healthy adult women.…”

Recurrent Urinary Tract Infection in the Gynecologic Practice: Time for Reviewing Concepts and Management

“…There is a variety of cranberry products on the market, and the optimal intake for the "active" ingredient to be effective in RUTIs prevention is still unknown. 8,10 Compared with placebo, water or no treatment, cranberry products did not significantly reduce the occurrence of symptomatic UTIs overall. The effectiveness of cranberries was also not significantly different compared with antibiotics for women.…”

“…The effectiveness of cranberries was also not significantly different compared with antibiotics for women. 10 Therefore, cranberry products cannot currently be recommended for the prevention of UTIs. 10 There are new promising strategies on the horizon for RUTI management, which are prophylaxis with bacterial extracts, such as the oral immunostimulant OM-89, or the vaginal vaccine Urovac.…”

Essentials of Herb-Drug Interactions in the Elderly With Cardiovascular Disease

“…18 Although a few small studies demonstrated benefit from cranberry use in women with recurrent UTIs, a 2012 Cochrane review showed no statistically significant differences when the results of a much larger study were included and recommended against the use of cranberry for UTI prevention. 33 This inconsistency in study results could be due to the variability in study designs, cranberry products used, study compliance or differences in pathogenesis of UTI in different groups such as young children, sexually active young adults or the elderly. Some case reports in the elderly 34,35 reported raised international normalized ratio (INR) and life-threatening bleeding with coadministration of warfarin and cranberry.…”

“…38 Due to these inconsistent findings, additional research is warranted to clarify cranberry's efficacy and safety in the elderly with multiple comorbidities. 33 Garlic Garlic (Allium sativum), a medicinal herb, has many potential benefits with its antimicrobial, immuneenhancing and anticholesterolemic effects, and is widely used for heart disease, high blood pressure, high cholesterol and prevention of stomach and colon cancers. Some clinical studies have shown aged garlic extract to be a safe adjunct treatment to conventional antihypertensives 39 and to improve glycemic control and lipid profile when used in combination with antidiabetics.…”