Effect of cranberry drink on bacterial adhesion in vitro and vaginal microbiota in healthy females.
Cranberries have been shown to produce urinary metabolites that influence uropathogen adhesion and prevent urinary tract infections. This study was designed to determine if consuming reconstituted, unsweetened cranberry drink from extract retained its bioactive properties by reducing uropathogen adhesion without adversely affecting urinary calcium, magnesium and the vaginal microflora.
A randomized crossover study was undertaken in 12 healthy women consuming reconstituted unsweetened cranberry drink, CranActin or water. The urine was collected at 4 hours and 1 week of consumption and evaluated for antiadhesive properties and urinary pH, calcium and magnesium. Vaginal swabs were collected after 1 week of treatment to assess the vaginal microbiota by DGGE.
RESULTS: The resultant urine produced by subjects who consumed 500 ml reconstituted cranberry extract twice per day, significantly reduced the adherence to epithelial cells of P-fimbriated uropathogenic Escherichia coli and showed a tendency towards significance for two E. coli strains expressing fimbriae and an Enterococcus faecalis isolate. The cranberry drink treatment did not alter urinary pH, but reduced calcium and magnesium concentrations compared to water, although not to statistical significance. The reconstituted cranberry drink had no apparent detrimental effect on the vaginal microbiota. However, consuming twice daily resulted in an apparent loss of a potential pathogen from the vagina in 42% subjects.
CONCLUSIONS: The present findings suggest that reconstituted cranberry drink may retain the ability to reduce the risk of UTI by inhibiting pathogen adhesion while not detrimentally affecting urinary pH or vaginal microbiota, or the risk of calculi.
SOURCE: Can J Urol. 2009 Dec;16(6):4901-7.
Cranberry juice for the prevention of recurrent urinary tract infections: a randomized controlled trial in children.
This study compares the effects of daily cranberry juice to those of Lactobacillus in children with recurrent urinary tract infections (UTIs).
Eighty-four girls aged between 3 and 14 years were randomized to cranberry, Lactobacillus or control in three treatment arms: G1, cranberry juice 50 ml daily (n=28); G2, 100 ml of Lactobacillus GG drink on 5 days a month (n=27); and G3, controls (n=29). The study lasted for 6 months.
RESULTS: Only four subjects withdrew: 1/28 (3.5%) from G1, 1/27 (3.7%) from G2 and 2/29 (6.8%) from G3, because of poor compliance to the established protocol. There were 34 episodes of UTIs in this cohort: 5/27 (18.5%) in G1, 11/26 (42.3%) in G2 and 18/27 (48.1%) in the G3, with at least one episode of infection (p<0.05).
CONCLUSION: These data suggest that daily consumption of concentrated cranberry juice can significantly prevent the recurrence of symptomatic UTIs in children.
SOURCE: Scand J Urol Nephrol. 2009;43(5):369-72.
Cranberry products are twice as cost effective than cranberry juice in the treatment of urinary tract infection in women.
This study was designed to determine, from a societal perspective, the effectiveness and cost effectiveness of concentrated cranberry tablets, versus cranberry juice, versus placebo used as prophylaxis against lower urinary tract infection (UTI) in adult women.
One hundred fifty sexually active women aged 21 through 72 years were randomized for one year to one of three groups of prophylaxis: placebo juice + placebo tablets versus placebo juice + cranberry tablets, versus cranberry juice + placebo tablets. Tablets were taken twice daily, juice 250 ml three times daily. Outcome measures were: (1) a >50% decrease in symptomatic UTI's per year (symptoms + >or= 100 000 single organisms/ml) and (2) a >50% decrease in annual antibiotic consumption. Cost effectiveness was calculated as dollar cost per urinary tract infection prevented. Stochastic tree decision analytic modeling was used to identify specific clinical scenarios for cost savings.
Both cranberry juice and cranberry tablets statistically significantly decreased the number of patients experiencing at least 1 symptomatic UTI/year (to 20% and 18% respectively) compared with placebo (to 32%) (p<0.05). The mean annual cost of prophylaxis was $624 and $1400 for cranberry tablets and juice respectively. Cost savings were greatest when patients experienced >2 symptomatic UTI's per year (assuming 3 days antibiotic coverage) and had >2 days of missed work or required protective undergarments for urgency incontinence. Total antibiotic consumption was less annually in both treatment groups compared with placebo. Cost effectiveness ratios demonstrated cranberry tablets were twice as cost effective as organic juice for prevention.
SOURCE: Can J Urol. 2002 Jun;9(3):1558-62.
Reduction of bacteriuria and pyuria after ingestion of cranberry juice.
This study was designed to determine the effect of regular intake of cranberry juice beverage on bacteriuria and pyuria in elderly women.
Subjects were randomly assigned to consume 300 mL per day of a commercially available standard cranberry beverage or a specially prepared synthetic placebo drink that was indistinguishable in taste, appearance, and vitamin C content but lacked cranberry content.
A baseline urine sample and six clean-voided study urine samples were collected at approximately 1-month intervals and tested quantitatively for bacteriuria and the presence of white blood cells.
Subjects randomized to the cranberry beverage had odds of bacteriuria (defined as organisms numbering > or = 10(5)/mL) with pyuria that were only 42% of the odds in the control group (P = .004). Their odds of remaining bacteriuric-pyuric, given that they were bacteriuric-pyuric in the previous month, were only 27% of the odds in the control group (P = .006).
These findings suggest that use of a cranberry beverage reduces the frequency of bacteriuria with pyuria in older women. Prevalent beliefs about the effects of cranberry juice on the urinary tract may have microbiologic justification.
JAMA. 1994 Mar 9;271(10):751-4
Cranberry or trimethoprim for the prevention of recurrent urinary tract infections? A randomized controlled trial in older women.
The objective of this study was to compare the effectiveness of cranberry extract with low-dose trimethoprim in the prevention of recurrent urinary tract infections (UTIs) in older women. One hundred and thirty-seven women with two or more antibiotic-treated UTIs in the previous 12 months were randomized to receive either 500 mg of cranberry extract or 100 mg of trimethoprim for 6 months.
RESULTS: Thirty-nine of 137 participants (28%) had an antibiotic-treated UTI (25 in the cranberry group and 14 in the trimethoprim group); difference in proportions relative risk 1.616 (95% CI: 0.93, 2.79) P = 0.084. The time to first recurrence of UTI was not significantly different between the groups (P = 0.100). The median time to recurrence of UTI was 84.5 days for the cranberry group and 91 days for the trimethoprim group (U = 166, P = 0.479). There were 17/137 (12%) withdrawals from the study, 6/69 (9%) from the cranberry group and 11/68 (16%) from the trimethoprim group (P = 0.205), with a relative risk of withdrawal from the cranberry group of 0.54 (95% CI: 0.19, 1.37).
CONCLUSIONS: Trimethoprim had a very limited advantage over cranberry extract in the prevention of recurrent UTIs in older women and had more adverse effects. Our findings will allow older women with recurrent UTIs to weigh up with their clinicians the inherent attractions of a cheap, natural product like cranberry extract whose use does not carry the risk of antimicrobial resistance or super-infection with Clostridium difficile or fungi.
SOURCE: J Antimicrob Chemother. 2009 Feb;63(2):389-95
Cranberries benefit men
Men can also suffer from UTI's especially after the natural decline of the immune system which occurs with aging.
Recent research has found that cranberries may relieve lower urinary tract symptoms in older men, thereby improving prostate health. A recent study included 42 men with an average age of 63 years. The participants were divided into two groups - one group received 1500 mg (about 3 capsules) of dried powdered cranberries every day for six months and the second group was given placebo pills for the duration of the study. The results revealed that men in the cranberry group experienced statistically significant improvements in all of the targeted markers, while no significant improvements were noted in the control group. Since the current medications can cause adverse effects, cranberries may be a beneficial new therapy. Now women are no longer the only ones to benefit from cranberries. This study showed men can benefit from the mighty red berries too. Cranberries are now proven to be an inexpensive, natural and effective way to treat urinary tract symptoms and support prostate health.
SOURCE: British Journal of Nutrition (2010), 104: 1181-1189