Cranberry juice has been recommended for patients with recurrent urinary tract infections. However, cranberry juice has a moderately high concentration of oxalate, a common component of kidney stones, and should be limited in patients with a history of nephrolithiasis. Cranberry concentrate tablets are marketed for urinary tract ailments. Physicians and manufacturers of cranberry products should make an effort to educate patients at risk for nephrolithiasis against ingestion of these dietary supplements.
- Urology 2001 Jan;57(1):26-9 -- Dietary supplementation with cranberry concentrate tablets may increase the risk of nephrolithiasis. -- Terris MK, Issa MM, Tacker JR.
Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). Information collected in this study was collected on methods, participants, interventions and outcomes (UTIs - symptomatic and asymptomatic, side effects, adherence to therapy). Cranberry products significantly reduced the incidence of UTIs at 12 months compared with placebo/control. Cranberry products were more effective reducing the incidence of UTIs in women with recurrent UTIs, than elderly men and women or people requiring catheterisation. Side effects were common in all studies, and dropouts/withdrawals in several of the studies were high. There is some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. It's effectiveness for other groups is less certain. The large number of dropouts/withdrawals indicates that cranberry juice may not be acceptable over long periods of time. It is not clear what is the optimum dosage or method of administration (e.g. juice, tablets or capsules). Further properly designed studies with relevant outcomes are needed.
- Cochrane Database Syst Rev. 2008 Jan 23;(1):CD001321. -- Cranberries for preventing urinary tract infections. --
Jepson RG, Craig JC.