Cranberry

 

Cranberry Clinical Report Summary

Written Exclusively for MyNutritionStore.com by Sarah Dzida 

 

Cranberry is widely used to prevent urinary tract infection (UTI) and research is also considering the possibility that cranberry may prevent conditions like dental plaque (1, 2).  There are multiple studies of cranberry juice and capsules that indicate it does prevent UTI most effectively in healthy women and the elderly (3-6).  However, while research has yet to make clear whether cranberry is an effective treatment for UTI, theories are considering cranberry as an adjunct treatment to proven antibiotics.  There is no accepted standardization for cranberry products because of its commercial use, for example, in food and drink products.  Many experts do recommend cranberry juice or capsules be taken orally in order to prevent UTI.  Theoretically, cranberry may counteract antacids due to its acidic pH.  Studies also suggest that cranberry is useful in mouth care; however, because many commercial cranberry products are high in sugar content, researchers cannot make a clear recommendation at this time.

 

Cranberry Overview

 

Cranberry is notably high in vitamin C content and is a demonstrated active agent against certain bacteria.  Research has proven that cranberry importantly inhibits bacteria like E.coli from sticking to cells that line the bladder due to one of its constituents: proanthocyanidin (8).  Studies also suggest that cranberry has antioxidant and antiviral properties, but experts have yet to make specific recommendations.  Traditionally, Native Americans used cranberries as food and as medicine for the prevention of kidney stones and removing toxins from the blood.  Today, scientists continue to research cranberry due to suggestive modern studies that indicate its potential use in many health conditions.

 

Safe Use of Cranberry

 

In regards to capsules, experts prescribe that one to six 300-400 mg hard gelatin concentrated cranberry juice extract capsules be taken twice daily, usually before meals (7).  In regards to juice, experts recommend 300 ml of cranberry juice taken daily (5, 6).  Persons with an allergy or hypersensitivity to the Vaccinium species like cranberries or blueberries should exercise caution.  Patients with a history of oxalate stones should limit their intake of cranberry juice to one liter per day or as advised by a physician.  Diabetic patients should only drink sugar-free cranberry juice to avoid high glycemic levels.

 

Clinical Studies for Cranberry

 

1. Cranberry and the Prevention of Urinary Tract Infection (UTI) in Women

 

First-time urinary tract infection and sexual behavior.  Foxman B, Geiger AM, Palin K, et al.

We studied the relation between sexual and health behaviors of women and first-time urinary tract infection (UTI). The study population was women using a university health service who were unmarried, had no UTI history, and who had engaged in sexual activity at least once. We found 86 cases of UTI, defined as one or more urinary symptoms and greater than or = 1,000 colony-forming units per ml urine of a known pathogen. We randomly sampled 288 controls from the student body. Vaginal intercourse increased the risk of UTI; this risk was further increased with condom use. After adjusting for vaginal intercourse with other birth control methods and recentness of current sexual partnership, a single sex act with a condom in the past 2 weeks increased UTI risk by 43%. Having a sex partner for less than 1 year vs 1 year or more, after adjustment for frequency of vaginal intercourse and birth control method, was associated with about twice the risk of UTI [odds ratio (OR) = 1.97; 95% confidence interval (CI) = 1.04-3.74]. After adjusting for frequency of vaginal intercourse, regular drinking of cranberry juice was protective against UTI (OR = 0.48; 95% CI = 0.19-1.02), whereas drinking carbonated soft drinks appeared to be associated with increased risk (OR = 2.37; 95% CI = 0.75-7.81). Using deodorant sanitary napkins or tampons was associated with a slight increase in risk of UTI (OR = 1.51; 95% CI = 0.74-3.06). Blacks had five times greater risk of UTI than whites after adjusting for frequency of vaginal intercourse (OR = 5.2; 95% CI = 1.89-24.63). We observed only modest differences in health behavior between racial groups.

 

2. Cranberry and the Prevention of Urinary Tract Infection (UTI) in the Elderly

 

Reduction of bacteriuria and pyuria after ingestion of cranberry juice.  Avorn J, Monane M, Gurwitz JH, et al.

Objective: To determine the effect of regular intake of cranberry juice beverage on bacteriuria and pyuria in elderly women.  Design: Randomized, double-blind, placebo-controlled trial.  Subjects: Volunteer sample of 153 elderly women (mean age, 78.5 years).  Intervention: 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.  Outcome Measures: 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.  Results: 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).  Conclusions: 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.

 

3. Cranberry and E.coli Inhibition

 

Inhibitory activity of cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eucaryotic cells.  Zafriri D, Ofek I, Adar R, et al.

Inhibition of bacterial adherence to bladder cells has been assumed to account for the beneficial action ascribed to cranberry juice and cranberry juice cocktail in the prevention of urinary tract infections (A. E. Sobota, J. Urol. 131:1013-1016, 1984). We have examined the effect of the cocktail and juice on the adherence of Escherichia coli expressing surface lectins of defined sugar specificity to yeasts, tissue culture cells, erythrocytes, and mouse peritoneal macrophages. Cranberry juice cocktail inhibited the adherence of urinary isolates expressing type 1 fimbriae (mannose specific) and P fimbriae [specific for alpha-D-Gal(1----4)-beta-D-Gal] but had no effect on a diarrheal isolate expressing a CFA/I adhesin. The cocktail also inhibited yeast agglutination by purified type 1 fimbriae. The inhibitory activity for type 1 fimbriated E. coli was dialyzable and could be ascribed to the fructose present in the cocktail; this sugar was about 1/10 as active as methyl alpha-D-mannoside in inhibiting the adherence of type 1 fimbriated bacteria. The inhibitory activity for the P fimbriated bacteria was nondialyzable and was detected only after preincubation of the bacteria with the cocktail. Cranberry juice, orange juice, and pineapple juice also inhibited adherence of type 1 fimbriated E. coli, most likely because of their fructose content. However, the two latter juices did not inhibit the P fimbriated bacteria. We conclude that cranberry juice contains at least two inhibitors of lectin-mediated adherence of uropathogens to eucaryotic cells. Further studies are required to establish whether these inhibitors play a role in vivo.

 

4. Cranberry and Plaque-Inhibiting Properties

 

Inhibiting interspecies coaggregation of plaque bacteria with a cranberry juice constituent.  Weiss EI, Lev-Dor R, Kashamn Y, et al.

Dental plaque stability depends on bacterial adhesion to acquired pellicle, and on interspecies adhesion (or coaggregation). A high-molecular-weight cranberry constituent at 0.6 to 2.5 milligrams per milliliter reversed the coaggregation of 49 (58 percent) of 84 coaggregating bacterial pairs tested. It acted preferentially on pairs in which one or both members are gram-negative anaerobes frequently involved in periodontal diseases. Thus, the anticoaggregating cranberry constituent has the potential for altering the subgingival microbiota, resulting in conservative control of gingival and periodontal diseases. However, the high dextrose and fructose content of the commercially available cranberry juice makes it unsuitable for oral hygiene use, and the beneficial effect of the high-molecular-weight constituent requires animal and clinical studies.

  

Cranberry References

 

1. Weiss EI, Lev-Dor R, Kashamn Y, et al. Inhibiting interspecies coaggregation of plaque bacteria with a cranberry juice constituent [published erratam appear in J Am Dent Assoc 1999 Jan;130(1):36 and 1999 Mar;130(3):332]. J Am Dent Assoc 1998;129(12):1719-1723.
2. Burger O, Ofek I, Tabak M, et al. A high molecular mass constituent of cranberry juice inhibits helicobacter pylori adhesion to human gastric mucus. FEMS Immunol Med Microbiol 2000;29(4):295-301.
3. Kontiokari T, Sundqvist K, Nuutinen M, et al. Randomised trial of cranberry-lingonberry juice and Lactobacillus GG drink for the prevention of urinary tract infections in women. BMJ 2001;322(7302):1571-1573.
4. Foxman B, Geiger AM, Palin K, et al. First-time urinary tract infection and sexual behavior. Epidemiology 1995;6(2):162-168.
5. Avorn J, Monane M, Gurwitz JH, et al. Reduction of bacteriuria and pyuria after ingestion of cranberry juice. JAMA 1994;271(10):751-754.
6. Avorn J, Monane M, Gurwitz J, et al. Reduction of bacteriuria and pyuria using cranberry juice. JAMA 1994;272(8):588-590.
7. Hughes BG, Lawson LD. Nutritional content of cranberry products. Am J Hosp Pharm 1989;46(6):1129.
8. Zafriri D, Ofek I, Adar R, et al. Inhibitory activity of cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eucaryotic cells. Antimicrob Agents Chemother 1989;33(1):92-98.