Cranberry supplement and juice benefit, side effects research, use for UTI and urinary tract health
February 1 2018 by
Ray Sahelian, M.D.


American cranberry (Vaccinium macrocarpon) is one of only three species of fruit native to North America. The other species are blueberry (Vaccinium angustifolia) and bilberry (Vaccinium myrtillus). Cranberry typically grows in bogs and is a member of the same family as blueberry and bilberry. Cranberry is widely used to prevent urinary tract infection (UTI). It was initially believed to function by acidifying urine. However, the mechanism is now thought to be inhibition of adhesion of bacteria to uroepithelial cells (cells lining the urethra) by proanthocyanadin, a compound present in cranberry.
   Cranberry like other fruits is also rich in phenolic phytochemicals such as flavonoids and ellagic acid. Consumption of cranberry has been shown to have a capacity to inhibit peptic ulcer-associated bacterium, Helicobacter pylori. Cranberries may also protect against heart disease and certain types of cancer, probably through the antioxidant and anti-tumor effects of flavonoids.


Benefit, what it is used for
The primary benefit in clinical practice is for the treatment or prevention of bladder infections. Drinking cranberry juice by itself offers little help. One has to consume a high potency extract or concentrate to have it work for UTI infection prevention or treatment.

Form of intake
You can get the benefits of cranberry by drinking the juice, diluting concentrate with water, taking capsules, or using a tincture. A cranberry supplement would minimize the high calories that come from drinking the juice.


UTI treatment or prevention
Cranberry fruit is used primarily for the prevention or treatment of urinary tract infections or bladder infections.
   The use of cranberry juice among individuals to prevent or treat bladder infection is a common practice. Cranberry may relieve symptoms associated with bladder infection and may reduce the need for antibiotics. Before the advent of antibiotics, cranberry juice continued to be a popular treatment for urinary tract infections (UTIs). The current proposed mechanism of action focuses primarily on cranberry's ability to prevent bacterial binding to host cell surface membranes. In vitro studies have observed potent inhibition of bacterial adherence of Escherichia coli4 and other gram-negative uropathogens.
   Cranberry was initially believed to function by acidifying urine. However, the mechanism is now thought to be inhibition of adhesion of bacteria to uroepithelial cells (cells lining inside the urethra and bladder wall) by proanthocyanadin, a compound present in cranberry. Proanthocyanidins bind to harmful bacteria such as E. coli, forming a "Teflon-like" coating around them. The coating prevents the bacteria from sticking to gastrointestinal and urinary tract walls, preventing infections.


J. Nutr. 2017. Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis.


Cranberry or trimethoprim for the prevention of recurrent urinary tract infections? A randomized controlled trial in older women.
J Antimicrob Chemother. 2009.
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. Thirty-nine of 137 participants (28%) had an antibiotic-treated UTI (25 in the cranberry group and 14 in the trimethoprim group). 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.


2009 - The results of a clinical study, recently published in the journal Spinal Cord, indicate that the use of Cran-Max Cranberry Concentrate for people with spinal cord injury resulted in a significant reduction in both the incidence of urinary tract infection (UTI) and the number of subjects with a UTI over a 12-month period. In the randomized, double-blind, cross-over trial, conducted at the Spinal Cord Injury Unit of the Veterans Administration Hospital in Boston, MA, 16 subjects had 21 UTIs while taking the placebo, compared to only six subjects who had seven UTIs while taking the Cran-Max cranberry concentrate. In the article, published in the 2008 edition of the journal, researchers concluded, “Despite advances in the management of neurogenic bladder, urinary tract infection represents a leading cause of morbidity and hospitalization. Cranberry extract tablets should be considered for the prevention of UTI in spinal cord injury patients with neurogenic bladder.” In the study, patients were randomly assigned to receive either Cran-Max tablets or placebo tablets for six months, followed by the alternative preparation for an additional six months. Of the 47 male subjects who completed the study, results showed that patients with a high glomerular filtration rate (a test to measure kidney function) received the most benefit from the cranberry supplement.


Children and UTI
Ann Pharmacother. 2015. Cranberry Products for the Prophylaxis of Urinary Tract Infections in Pediatric Patients. Cranberry appears effective for the prevention of UTIs in otherwise healthy children and is at least as effective as antibiotics in children with underlying urogenital abnormalities.


Daily cranberry juice for the prevention of asymptomatic bacteriuria in pregnancy: a randomized, controlled pilot study.
J Urology 2008.
We compared the effects of daily cranberry juice cocktail to those of placebo during pregnancy on asymptomatic bacteriuria and symptomatic urinary tract infections. Our data suggest there may be a protective effect against asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy. Further studies are planned to evaluate this effect.


Benefit in men
Cranberries may be of benefit in reducing lower urinary tract symptoms (LUTS) in older men, thereby, improving prostate health. Researchers treated 42 men with an average age of 63 years who had LUTS with benign prostatic hyperplasia (BPH). They took 1500 mg of dried powdered cranberry or placebo for 6 months. The cranberry treated group experienced improvement in rate of urine flow, average flow, and had lower total PSA levels. Vidlar A, Vostalova J. The effectiveness of dried cranberries (Vaccinium macrocarpon) in men with lower urinary tract symptoms. Br J Nutr. 2010.


Cranberry juice versus cranberry supplement for UTI
For prevention of urinary tract infections, one has to consider the cost of regularly drinking cranberry juice, as well as the extra calories. As for cranberry supplements, two studies suggested they may work, but cranberry supplements come in a wide range of different strengths. Optimal dose of cranberry supplements and duration of use is not understood well. It is not fully known whether cranberry supplements are equivalent to cranberry juice in the fruit's biologically active substances.


Cholesterol impact
Favourable impact of low-calorie cranberry juice consumption on plasma HDL-cholesterol concentrations in men.
Br J Nutr. 2006. Institute of Nutraceuticals and Functional Foods, Laval University, Quebec, Canada and Lipid Research Center Laval University Medical Research Center, Quebec Canada.
Studies have suggested that flavonoid consumption may be cardioprotective, and a favourable impact on circulating HDL-cholesterol concentrations has been suggested to partially explain this association. The aim of the present study was to determine the effect of consuming increasing daily doses of low-calorie cranberry juice cocktail (CJC) on the plasma lipid profile of abdominally obese men. For that purpose, thirty men consumed increasing doses of CJC during three successive periods of 4 weeks (125 ml/d, 250 ml/d, 500 ml/d). We noted a significant increase in plasma HDL-cholesterol concentration after the consumption of 250 ml CJC/d, an effect that plateaued during the last phase of the stud). Changes in plasma apo A-I and triacylglycerol concentrations were the only variables significantly contributing to the variation in plasma HDL-cholesterol concentration noted in response to the intervention. No variation was observed in total as well as in LDL and VLDL cholesterol. The present results show that daily CJC consumption is associated with an increase in plasma HDL-cholesterol concentrations in abdominally obese men. Polyphenolic compounds from cranberries may be responsible for this effect, supporting the notion that the consumption of flavonoid-rich foods can be cardioprotective.


Heart and blood vessel health
J Nutr. 2015. Cranberry Juice Consumption Lowers Markers of Cardiometabolic Risk, Including Blood Pressure and Circulating C-Reactive Protein, Triglyceride, and Glucose Concentrations in Adults. The objective of this study was to determine the potential of low-calorie cranberry juice (LCCJ) to lower cardiometabolic risk. A double-blind, placebo-controlled, parallel-arm study was conducted with controlled diets.  LCCJ can improve several risk factors of CVD in adults, including TGs, CRP, glucose, insulin resistance, and diastolic BP. This trial was registered at as NCT01295684.


Teeth and tooth health
New research shows a generous helping of cranberry sauce may actually offer benefits for their teeth. Cranberries, which already are known to help thwart urinary tract infections, may also prevent tooth decay and cavities, dental researchers reported in the January, 2006 issue of the journal Caries Research. The same sticky compounds in the small, hard red fruit -- which is boiled into a jelly that is a staple at American winter holiday meals -- that help keep bacteria at bay in the bladder also appear to help prevent bacteria from clinging to teeth. They also found cranberry seemed to help ward off plaque, a gooey substance formed from bits of food, saliva, and acid that can harbor bacteria and eventually irritate the gums. The ultimate goal is to extract cranberry's protective properties and add them to toothpaste or mouthwash. In the meantime, people should be advised against drinking or eating excessive amounts of cranberry -containing products since sugar is often added to cranberries. The cranberry seed has not been studied as much as the juice.


Chemical composition
Cranberry contains a number of compounds including proanthocyanidins, anthocyanidins, flavonoids, and hydroxycinnaminic acid. Flavonoids in cranberries contribute to the red color and have antioxidant properties. Most of the compounds in cranberry are antioxidants. The profile of cranberry bioactives is distinct from that of other berry fruit, being rich in A-type proanthocyanidins in contrast to the B-type proanthocyanidins present in most other fruit. Human studies on the health effects of cranberry products have focused principally on urinary tract and cardiovascular health, with some attention also directed to oral health and gastrointestinal epithelia.


Historical uses
Early European settlers first used cranberries because the local fruit lasted through the winter and enhanced the flavor of gamy meat. The settlers had learned about the berry's culinary potential from local Native Americans who endured cold winters by consuming pemmican, a cake of cranberries, nuts and dried venison or bear meat.
   The ripe cranberry fruit was used medicinally by Native Americans for the treatment of bladder and kidney ailments. Pilgrims called the fruit "craneberry" because the stem and flower resembled the head, neck, and beak of a crane. Therapeutic applications of cranberries documented during the 17th century included the relief of blood disorders, stomach ailments, liver problems, vomiting, appetite loss, scurvy, and cancer. Native Americans and Europeans prescribed cranberries for fevers, gastrointestinal problems and dropsy  Dropsy is a term used to describe inflammation or swelling.


Food poisoning protection

Cranberry extract may reduce the likelihood of food-borne disease. Pathogen levels in raw meat are reduced after the application of cranberry concentrate. These include significantly reduced growth of Salmonella, E. coli and other dangerous bacteria. Compounds in cranberries inhibit the growth of bacteria associated with food-borne illnesses. Other research has found cranberry juice reduces E. coli, Salmonella and other bacteria in unpasteurised apple cider. Cranberries are known to have "anti-adhesion" properties that protect the body from certain harmful bacteria that cause urinary tract infections, stomach ulcers and gum disease.
     In the US, PepsiCo Inc. and Ocean Spray have formed a long-term strategic alliance under which Pepsi-Cola North America will distribute single-serve cranberry juice products in North America under the Ocean Spray name.


The cranberry is full of antioxidants. The National Institutes of Health is funding research on the effect of cranberry on heart disease, yeast infections and other conditions, and other researchers are investigating its potential against cancer, stroke and viral infections. So far, research has found drinking cranberry juice can block urinary infections by binding to bacteria so they can’t adhere to cell walls. Women often drink unsweetened cranberry juice to treat an infection. A compound discovered in cranberry, proanthocyanidine, prevents plaque formation on teeth; mouthwashes containing it are being developed to prevent periodontal disease. In some people, regular cranberry juice consumption for months can kill the H. pylori bacteria, which can cause stomach cancer and ulcers. Drinking cranberry juice daily may increase levels of HDL, or good cholesterol and reduce levels of LDL, or bad cholesterol. Cranberry may prevent tumors from growing rapidly or starting in the first place. Extracts of chemicals in cranberry prevent breast cancer cells from multiplying in a test tube; whether that would work in women is unknown.


Cranberry availability from herb and ingredient suppliers
Cranberry is available as a plain cranberry juice concentrate powder or in various extract potencies, for instance 4 to 1, 12 to 1, 18 to 1 concentrations. One supplier sells cranberry extract as 30 percent total acid, 10 percent quinic acid and 3 percent total phenols.


Cranberry side effect, caution, risks, danger, interaction with medications

Fatal hemopericardium and gastrointestinal hemorrhage due to possible interaction of cranberry juice with warfarin Coumadin.
J R Soc Health. 2008.
We report a case of fatal internal hemorrhage in an elderly man who consumed only cranberry juice for two weeks while maintaining his usual dosage of warfarin (Coumadin). We propose that naturally occurring compounds such as flavonoids, which are present in fruit juices, may increase the potency of warfarin by competing for the enzymes that normally inactivate warfarin. While traditionally regarded as foodstuffs, consumption of fruit juices should be considered when patients develop adverse drug reactions.

Elevated International Normalized Ratio after concurrent ingestion of cranberry sauce and warfarin.
Am J Health Syst Pharm. 2008.
A case of increased International Normalized Ratio (INR) values in a patient receiving warfarin who consumed a large amount of cranberry sauce is reported. A 75-year-old Caucasian man with atrial fibrillation was taking 22.5 mg of warfarin weekly for 10 months and had maintained stable INR values between 2 and 3. During a clinic visit one week after Thanksgiving, the patient's INR was 4.8. The patient was extensively questioned about any changes in his diet, medications, and health. The patient reported consuming approximately 110 g of cranberry sauce for seven consecutive days before the clinic visit. He reported no other diet or health changes. The patient denied alcohol consumption, had not taken nutritional supplements, and did not miss or double any medication doses during this time period. The patient's complete blood cell count and results of a chemistry panel and liver function tests were within normal limits. He did not have any bleeding or bruising. The only identifiable change was the addition of store-bought cranberry sauce to his diet. The patient's warfarin dose was held for two days. Subsequently, the patient resumed warfarin at a dosage of 20 mg per week. Seven days after the patient discontinued the cranberry sauce, his INR returned to 2.2 and remained stable over the next month. Consumption of cranberry sauce led to an increase in INR values in a patient receiving warfarin.


I wanted to forward a study reference conducted by warfarin expert Jack Ansell, MD who evaluated the myth (originating only from isolated case studies in England) that cranberry products can elevate INR test results. Dr. Ansell found that normal consumption of cranberry products really had no affect on patient INRs and therefore not a contributor to elevated bleeding risk. Reference: Ansell, J. 2009. The Absence of an Interaction Between Warfarin and Cranberry Juice: A Randomized, Double-Blind Trial. Journal of Clinical Pharmacology. I saw you advise patients are at risk of bleeding for cranberry and cranberry products. We provide information for our visitors that cranberry can be safely consumed in normal quantities by patients taking warfarin. Gary B Liska, Disease Management / Provider Relations Quality Assured Services, Inc.

Do sweetened dried cranberries have similar bladder benefits as the juice?
    Dried cranberries do contain the anti-adhesion mechanism present in cranberry juice, puree and concentrate that prevents urinary tract infections. However, I am not thrilled about the added sugar.


I am in the process of buying Prostate Power Rx and, besides, I am going to take a cranberry (Vaccinium macrocarpon) supplement that it seems to improve the urinary flow according to a Wikipedia statement. Is there any side effect if I take both products together?
    It is not possible for us to predict any one person's reaction to a supplement, a combination of supplements, or combining with medications but we do not see any obvious negative interactions.


Natural Factors, CranRich, Super Strength Cranberry Concentrate, 500 mg, 180 Capsules
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Supplement Facts
Serving Size: 1 Capsule
  Amount Per Serving % Daily Value
CranRich Cranberry (Vaccinium macrocarpon) Concentrate (36:1) (Fruit) 500 mg **
** Daily Value not established.

Buy Cranberry Concentrate extract pills
Genitourinary Tract Support
Herbal Supplement
Cranberry is widely used to support the health of the genitourinary tract. Research has shown that it has an anti-adhesion factor that prevents bacteria from attaching to the walls of the urinary tract. This concentrated extract has a broad spectrum of cranberry's valuable plant acids. Each pill is equivalent to drinking several ounces of cranberry juice.

Lifestyle Recommendations: To support the health of the genitourinary tract, drink plenty of pure water; avoid the excessive consumption of sugar, which can lead to increased bacterial levels; and reduce caffeine and alcohol, which may irritate the bladder.