Mechanistic Studies: Antiadherent Properties
Adherence of uropathogens to uroepithelial cells is the initial step in pathogenesis of UTI . In 1984, Sobota was first to suggest that reported benefits derived from the use of cranberry juice may be related to its ability to inhibit bacterial adherence . Sobota found that cranberry juice cocktail reduced adherence by > 75% in > 60% of 77 clinical isolates of E. coli recovered from patients with UTI. Fifteen of 22 subjects showed significant antiadherence activity in their urine 13 h after drinking 15 oz of cranberry juice cocktail .
Since Sobota’s initial report, several studies have confirmed that the presumed efficacy of cranberry in preventing UTI is related to its antiadherent properties. It is now known that E. coli, the most common cause of UTI, have hairlike fimbria that protrude from their surface. The fimbriae produce 2 adhesins that attach to receptors on uroepithelial cells .
Cranberry Capsules Reduce The Prevalence Of Uti
The team studied 160 patients aged 23-88 years who were undergoing elective gynecological surgery between 2011-2013. Normally, 10-64% of women undergoing this kind of surgery will develop a UTI following the removal of the catheter.
Half of the patients received two cranberry juice capsules twice daily the equivalent in strength to two 8-ounce servings of cranberry juice for 6 weeks after surgery. The others took a placebo.
Cranberry capsules lowered the risk of UTIs by 50%. In the cranberry treatment group, 19% of patients developed a UTI, compared with 38% of the placebo group.
So, how does it work? For a UTI to occur, bacteria must adhere to and invade the lining of the bladder. Cranberries contain A-type proanthocyanidins , which interfere with the bacterias ability to the bladder wall, reducing the likelihood of infection.
Study Selection Data Extraction And Quality Assessment
The cumulative incidence of participants with 1 UTI was used for pooled risk ratio estimates. The risk of bias assessment for each study included random sequence generation , allocation concealment , blinding of participants and personnel , blinding of outcome assessment , incomplete outcome data , selective outcome reporting , and other bias . Each risk of bias item was scored as low, high, or unclear. Abstract and full-text screenings, data extraction, and quality assessment, which used the Cochrane risk of bias assessment guideline , were conducted by 2 independent researchers and discrepancies were resolved by group consensus.
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Probably Not A Great Treatment For Active Utis
While cranberry products help protect against UTI recurrence in some people, evidence supporting the use of cranberry juice and cranberry juice products for improving symptoms in people who have active UTIs is weak.
One review that included three high quality studies concluded that, overall, there wasnt enough evidence to show that cranberry extract helps treat active UTIs .
Another study that included 46 women found that taking cranberry capsules both alone and when combined with antibiotics may help reduce the need for antibiotic use and improve certain UTI-related symptoms in women with active UTIs .
Its important to note that this was a feasibility study with 46 participants, designed to assess whether a larger scale study would be feasible. Thus, its results may not be as robust as the results of a larger, high quality study.
Some women in the study noted that taking the cranberry supplements helped reduce antibiotic use and helped clear the infection more quickly than antibiotics alone, while others reported no improvement when they took the cranberry supplements.
Its important to note that most available research focuses on using cranberry products to prevent UTIs, not treat active infections.
Currently, theres not enough evidence to suggest that cranberry products are effective at reducing UTI symptoms or speeding recovery from active UTIs.
Data Synthesis And Analysis
Meta-analyses were performed using Stata SE software . Statistical significance was defined as P< 0.05 , unless otherwise stated. Heterogeneity was quantified using both the I2 statistic and the chi-square test, with an I2 value of 50% considered substantial heterogeneity. We employed a fixed-effect model using the Mantel-Haenszel method to estimate the summary risk if the heterogeneity was low to moderate . Otherwise, we applied a random-effects model using the DerSimonian-Laird method . As the primary summary risk estimate, the risk ratio was calculated as a measure of effect for dichotomous outcomes in individual studies. If there was > 1 time point for UTI measures , UTI data reported as the primary outcome in the publication were used for the main risk ratio estimate. A funnel plot was drawn to visually evaluate small-study effects, formerly known as publication bias testing . Because of the small number of included studies , the interpretations of funnel plot symmetry are limited and thus no statistical testing was done.
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Tips To Prevent A Urinary Tract Infection
A urinary tract infection, also called a UTI, is an infection that occurs in the urinary system. This could include the urethra, bladder, ureters and kidneys. Most infections involve the bladder and urethra, known as the lower urinary tract.
The most common symptoms include painful urination, tenderness above the bladder area, urgency and frequency of urination. Cloudy and a strong odor are not signs of infection.
Women are at greater risk for a UTI because the urethra is shorter than in men, so it’s easier for bacteria to travel to the bladder. UTIs also are more common in postmenopausal women because low estrogen levels change vaginal and urethral tissue to increase the risk of infection.
It’s always better to prevent an infection rather than simply treat it. UTIs are no different.
Contraindications Interactions Adverse Effects
Cranberry has a record of safety, although specific long-term safety data are lacking. No significant herb-drug interactions have been reported. A single study23 found that cranberry may increase the absorption of vitamin B12 in patients who also are taking proton pump inhibitors and that it may allow the kidneys to metabolize weakly alkaline drugs more rapidly, thus reducing their effectiveness. A small study24 found a significant rise in urinary oxalate levels, prompting a caution that regular use of cranberry may increase the risk of kidney stone formation in patients with a history of oxalate calculi.
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Summary Of Main Results
In the last update of this review we concluded that ‘There was some evidence to show that cranberries can prevent recurrent infections in women. However, the evidence for elderly men and women was less clear, and there is evidence that is not effective in people who need catheterisation. In this update, with the addition of 14 new studies, it has become more evident that cranberry products do not significantly reduce the risk of repeat symptomatic UTI compared to placebo or no treatment in groups of people at risk of repeat UTI or for any of the subgroups analysed. There was however moderate heterogeneity , which is largely unexplained. The two studies in children suggest the greatest effect , however this result was not significant, reflecting the small sample size and infrequency of events. In adult women and the elderly the CIs were wide and do not reach not statistical significance. Studies in pregnant women, patients with spinal injury or neuropathic bladder, people with multiple sclerosis, and people receiving radiation therapy showed no significant benefit to cranberry product with RRs close to 1.
Cranberry Juice And Utis: Myth Vs Science
UTIs are a common bacterial infection, especially among women.
In fact, 50% of women, compared with 12% of men, will develop a UTI in their lifetime. Whats more, up to 30% of young women have recurrent UTIs, which can significantly affect their quality of life (
In addition to medications like antibiotics, many people use natural remedies for UTI prevention and treatment.
Cranberry juice and cranberry juice supplements are perhaps the most popular natural treatments for UTIs.
Cranberries contain compounds such as phenolic acids and flavonoids, which may help treat and prevent UTIs.
These compounds may help (
- interfere with the ability of bacteria to stick to the lining of the urinary tract
- reduce inflammation
- modulate gut bacteria
Nevertheless, you may wonder whether cranberry juice is effective at preventing and treating UTIs.
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Benefits Of Cranberry Supplements
Cranberry supplements may help prevent and treat urinary tract infections, help strengthen your urinary tract walls, and support your overall immune system so you’re at a lower risk of infection. Cranberry naturally contains high levels of antioxidants that help fight free radicals and their oxidative damage. It also contains vitamin C which is known for its immune-boosting properties.
Some brands add vitamin C and other micronutrients to further enrich their products and help protect your overall health and well-being.
Cranberries Help Urinary Tract Infections But Not As Juice
Dashing out for a bottle of cranberry juice when a urinary tract infection hits may not be so helpful after all. Research published in the American Journal of Obstetrics and Gynecology suggests it could just be an old wives tale.
A urinary tract infection can affect any part of the urinary system, kidneys, bladder or urethra.
More than 3 million Americans, mostly women, experience a UTI every year.
Symptoms include frequent, painful urination, pelvic pain and traces blood in the urine. The infection does not normally last long, and most patients self-diagnose.
For many, the first port of call is a box of cranberry juice. However, new research suggests that while cranberry capsules can help, cranberry juice may be little more than a panacea.
Dr. Timothy Boone, PhD, vice dean of the Texas A& M Health Science Center College of Medicine in Houston, and colleagues wanted to know if cranberries can really help.
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Effective Ayurvedic Medicine & Remedies For Uti
Clinical Efficacy Of Sdc Consumption In Uti
There was a significant reduction in the incidence of UTIs and time until first UTI recurrence in women consuming SDC, as determined by two separate statistical analyses. First, the six-month UTI rate was compared pre- and post-consumption. Nine of 17 patients reported no UTIs within six months since beginning the study, and the mean UTI rate per six months decreased significantly from 2.4 to 1.1 . Since three patients were taking daily antibiotic prophylaxis which may affect the results, the clinical efficacy was determined with and without these patients. When these women were excluded from analysis, the six-month UTI rate also significantly decreased .
Six-month UTI rates Pre- and Post- sweetened dried cranberry consumption. In 17 patients, the mean pre- and post- SDC consumption UTI rates were 2.4 and 1.1, respectively . The pre-consumption UTI rate is based on one half of the total number of UTIs in the past year or the total UTIs in six months prior to entering the study. Post-consumption six-month UTI rate is based on the total number of UTIs reported six months since beginning the study.
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Cranberries For Urinary Tract Infections
Researchers have found a new use for cranberries in combating bacterial infections, including preventing bacterial colonization in urinary catheters.
Two studies published in the Canadian Journal of Microbiology and Colloids and Surfaces B: Biointerfaces revealed that cranberry powder can inhibit the bacterium Proteus mirabilis, a bug commonly found in complicated urinary tract infections .
The research, by chemical engineering scientists at Montreals McGill University, showed that increasing the concentration of cranberry powder reduced the bacterias production of urease, an enzyme that helps the infection to spread.
Previous studies from the same McGill laboratory found that cranberry materials can limit the movement of bacteria found in UTIs. In an analysis of E. coli found in the bladder, their work showed that exposure to cranberry extracts caused decreased expression of the gene that encodes for the bacteriums flagellar filament.
The researchers say their work is significant as the movement of bacteria is a key mechanism for the spread of infection. The bacteria swim in order to spread in the urinary tract and escape the immune system.
Professor Nathalie Tufenkji, study leader, says:
But this most recent research revealed that cranberry-enriched silicone substrates disabled the spread of Proteus mirabilis.
This could lead to cranberry extracts being used to limit the spread of germs in implantable medical devices such as catheters, the researchers say.
Data Collection And Analysis:
Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes . Risk ratios were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane risk of bias assessment tool.
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What To Look For In Cranberry Supplements
When it comes to choosing the best cranberry supplements, these are some important factors to keep in mind:
- Quality of ingredients: Always choose brands with the highest-quality ingredients to ensure a high level of micronutrients.
- Clean formula: The best cranberry supplements contain no unnecessary and artificial ingredients that might contribute to overall inflammation in your body and increase your risk of infections. They also contain no gluten, sugars, dairy, or GMOs.
- Added ingredients: Some brands add vitamin C, E, or other natural ingredients that enrich their formula and help improve more aspects of your health and well-being.
- Organic certificate: Even though a brand doesn’t have to carry an organic label to ensure quality, if there is one, it does help you choose better because you know their formula is high-quality and clean
- Third-party tested: If a brand provides third-party testing results, it ensures potency, purity, high quality, and transparency into their sourcing as well as production and handling.
- Testimonials: Reviews and testimonials from real customers always trump whatever the brand promotes on its website.
Criteria For Considering Studies For This Review
Types of studies
All RCTs of cranberry juice versus placebo, no treatment or any other treatment. QuasiRCTs were included, but the quality of the studies was taken into account during the analysis and discussion. Both parallel group and crossover design were included.
Types of participants
Studies of susceptible men, women or children as defined below. These categories were analysed separately.
- Participants with a history of recurrent lower UTIs
- Elderly men and women
- Participants with an indwelling catheter
- Participants with an abnormality of the urinary tract
- Children with a first or subsequent UTI.
- Studies of the treatment of asymptomatic or symptomatic UTI .
- Studies of any urinary tract condition not caused by bacterial infection .
Types of interventions
Cranberry juice or a cranberry product taken by participants for at least one month. The amount taken/d, concentration of the juice/cranberry product and length of treatment was also taken into account in subgroup analyses.
Types of outcome measures
- Number of UTIs in each group , midstream specimen of urine if possible, or a ‘clean catch’ specimen).
If further studies become available for review, this outcome will also be subgrouped into rate of symptomatic lower UTIs, rate of symptomatic upper UTIs and rate of asymptomatic UTIs. Symptomatic is defined as having one or more or the following symptoms: dysuria, frequency, urgency or fever.
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How Cranberry Juice Treats Urinary Tract Infections
A mixture of cranberry juice, water, and sweeteners found in cranberry juice cocktail was used for the study because it is the most popular cranberry beverage. The researchers discovered that in petri dishes, cranberry metabolites in the juice prevented E. coli from sticking to other bacteria, limiting its ability to grow and multiply. If E. coli is able to connect with other bacteria, such as the bacteria found in the urinary tract, it forms a layer or “biofilm.” This allows the bacteria to multiply and produce an infection.
“A number of controlled clinical trials — these are carefully designed and conducted scientific studies done in humans — have concluded that cranberry juice really is effective for preventing urinary tract infections,” says study researcher Terri Anne Camesano, PhD, in a news release. “That has important implications, considering the size of the problem and the health care costs involved.”
Urinary tract infections are more common among women than men. According to the researchers, one in three women has had a urinary tract infection.
Urinary tract infections can occur anywhere along the urinary tract, which includes the bladder, urethra, and ureter. These infections account for 8 million trips to the doctor’s office every year and cost more than $1.6 billion to treat.
Search Methods For Identification Of Studies
We searched the Cochrane Renal Group’s Specialised Register through contact with the Trials’ Search Coordinator using search terms relevant to this review.
The Cochrane Renal Groups Specialised Register contains studies identified from:
Studies contained in the Specialised register are identified through search strategies for CENTRAL, MEDLINE, and EMBASE based on the scope of the Cochrane Renal Group. Details of these strategies as well as a list of handsearched journals, conference proceedings and current awareness alerts are available in the ‘Specialised Register’ section of information about the Cochrane Renal Group.
See Appendix 1 for search terms used in strategies for this review.
Relevant studies were obtained from the following sources.
- The following terms were searched to identify nonEnglish language studies:
- Portuguese and
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