Cranberry (Vaccinium macrocarpon)


There is some human evidence supporting the use of cranberry juice and cranberry supplements to prevent urinary tract infection (UTI), although most available studies are of lesser quality. Clear dosing guidelines are lacking, but given the safety of cranberry, it may be reasonable to recommend the use of moderate amounts of cranberry juice cocktail to prevent UTI in non-chronically ill individuals.
Cranberry has not been shown effective as a treatment for documented UTI. Although cranberry may be used as an adjunct therapy in some cases, given the proven efficacy of antibiotics, cranberry should not be considered a first-line treatment.
Cranberry has been investigated for numerous other medicinal uses, and promising areas of investigation include prevention of H. pylori infection, which causes gastrointestinal ulcers and dental plaque.

Related Terms

American cranberry, arándano americano (Spanish), arándano trepador (Spanish), bear berry, black cranberry, bog cranberry, Ericaceae (family), European cranberry, grosse Moosebeere (German), isokarpalo, Kranbeere (German), Kronsbeere (German), large cranberry, low cranberry, marsh apple, Moosebeere (German), mossberry, mountain cranberry, Oxycoccus hagerupii, Oxycoccus macrocarpus, Oxycoccus microcarpus, Oxycoccus palustris, Oxycoccus quadripetalus, pikkukarpalo (Finnish), Preisselbeere (German), ronce d'Amerique (French), trailing swamp cranberry, tsuru-kokemomo (Japanese), Vaccinium edule, Vaccinium erythrocarpum, Vaccinium hageruppi, Vaccinium microcarpum, Vaccinium occycoccus, Vaccinium plaustre, Vaccinium vitis.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Achlorhydria and B12 absorption (Grade: C)
Preliminary research suggests that cranberry juice may increase vitamin B12 absorption in patients taking antacids (drugs that reduce stomach acid), such as proton pump inhibitors like lansoprazole (Prevacid®). However, this effect may be due to the acidity of the juice rather than an active component of cranberry itself. Further research is needed before a recommendation can be made.
Antibacterial (Grade: C)
Research results of cranberry as an antibacterial show conflicting results. Further research is needed before a conclusion can be drawn.
Antioxidant (Grade: C)
According to laboratory research, cranberry may have antioxidant properties. However, human research is lacking. Further research is needed before a recommendation can be made.
Antiviral and antifungal (Grade: C)
Limited laboratory research has examined the antiviral and antifungal activity of cranberry. There is a lack of reliable human studies supporting the use of cranberry in this area.
Cancer prevention (Grade: C)
Based on a small amount of laboratory research, cranberry has been proposed for cancer prevention. Research is needed in humans before a strong recommendation can be made.
Cardiovascular disease (Grade: C)
In preliminary human research on patients with coronary artery disease, consumption of cranberry juice reduced the carotid femoral pulse wave velocity, a measurement of arterial stiffness. Further research is required.
Chronic urinary tract infection prophylaxis (in children with neurogenic bladder) (Grade: C)
There is preliminary evidence that cranberry may be effective in preventing urinary tract infections in children with neurogenic bladder.
Dental plaque (Grade: C)
Because of its activity against some bacteria, cranberry juice has been proposed as helpful for mouth care. However, many commercial cranberry juice products are high in sugar and may not be suitable for this purpose. There is not enough research in this area to make a clear recommendation.
Diabetes (Grade: C)
According to a single trial from a systematic review, effects of cranberry on blood sugar levels in patients with diabetes are lacking. Further research is required.
H. pylori infection (Grade: C)
Based on early research, cranberry may reduce the ability of
Kidney stones (Grade: C)
According to preliminary research, it is not clear if drinking cranberry juice increases or decreases the risk of kidney stone formation. Cranberry juice is reported to decrease urine levels of calcium, increase levels of urine magnesium and potassium, and increase urine levels of oxalate.
Lipid lowering effects (Grade: C)
The lipid-lowering effects of cranberry were observed in individuals with obesity or diabetes. At this time evidence in support of these effects is lacking. Further research is required.
Memory improvement (Grade: C)
Preliminary research results show that cranberry juice may increase overall ability to remember. Further well-designed clinical trials are needed to confirm these results.
Metabolic syndrome (Grade: C)
In early research, cranberry juice lacked effect on cardiovascular disease risk factors in patients with metabolic syndrome. Further research is required.
Radiation therapy side effects (prostate cancer) (Grade: C)
There is preliminary evidence that cranberry is not effective in preventing urinary symptoms related to pelvic radiation therapy in patients with prostate cancer.
Reduction of odor from incontinence/bladder catheterization (Grade: C)
There is preliminary evidence that cranberry juice may reduce urine odor from incontinence or bladder catheterization. Further research is needed before a firm recommendation can be made.
Stress (Grade: C)
The effect of a cranberry supplement in female surgeons with stress-related disorders has been studied. Although there is evidence of benefit, further research is required.
Urinary tract disorders (LUTS) (Grade: C)
Cranberry fruit powder improved International Prostate Symptom Score (IPSS) and quality of life in men with lower urinary tract symptoms (LUTS) and presenting with elevated levels of prostate-specific antigen (PSA) and/or benign prostatic hyperplasia (BHP). Further well-designed research is required.
Urinary tract infection (prevention) (Grade: C)
There are multiple studies of cranberry (juice or capsules) for the prevention of urinary tract infections (UTIs) in healthy women, pregnant women, individuals with spinal cord injuries, and nursing home residents. While no single study convincingly demonstrates the ability of cranberry to prevent UTIs, the sum total of favorable evidence combined with laboratory research tends to support this use. It is not clear what dose is best.
Urinary tract infection (treatment) (Grade: C)
There is a lack of well-designed human studies of cranberry for the treatment of urinary tract infections. Laboratory research suggests that cranberry may not be an effective treatment when used alone, although it may be helpful as an adjunct to other therapies such as antibiotics.
Urine acidification (Grade: C)
In large quantities, cranberry juice may lower urine pH, making it more acidic. Contrary to prior opinion, urine acidification does not appear to be the way that cranberry prevents urinary tract infections. More research is needed in this area.
Urolithiasis (Grade: C)
Although cranberry consumption may increase urinary excretion of oxalate, possibly predisposing to calcium oxalate stone formation, it also increases magnesium and potassium excretion, which may decrease the rate of stone formation. Cranberry juice of unspecified amounts has been found to decrease urinary calcium by 50% in patients with renal stones. The clinical significance and net outcome of these findings in various subgroups has not been elucidated.
Urostomy care (Grade: C)
It is proposed that skin irritation at urostomy sites may be related to urine pH. Cranberry juice can lower urine pH and has been tested for this purpose. Further research is needed before a recommendation can be made.