Written by James C. Morton Jr., Staff Writer. In a randomized placebo-controlled clinical research study, cranberry extract significantly reduces urinary tract infection factors (75.8%) related to E. Coli compared to baseline and placebo group.
Urinary Tract Infections (UTI) are one of the most common health problems affecting people of all ages, with more women than men being affected in the bladder and urethra of the urinary system. It is characterized by a bacterial infection invading any part of the urinary system (bladder, urethra, ureters, and kidneys) (1). Recurrent UTI’s are classified when there are three episodes within a 12-month period or two episodes within the last 6 months (2). Escherichia Coli (E. Coli) is the most common organism, causing 85% of UTI infections and 50% for nosocomial infections (3). The latest statistical estimated healthcare cost for UTI’s is near $4 billion a year in the United States (4).
The most popular treatment approach for urinary tract infection (UTI) or recurrent UTI in patients is the use of a prescription medication involving an antibiotic that works with the immune system to eliminate the bacteria. Other chemical medication may also be prescribed to relieve pain during urination. Unfortunately, the frequent use of antibiotics has developed bacteria resistance to some antibiotics, and this causes the treatment to be prolonged (5).
Fortunately, a 2016 study (6) reveals that cranberry extract (proantocyanidin-A) reduces factors to recurrent UTI’s. The study involved 72 patients (aged 15 to 76), divided into two equal groups with recurrent UTI’s. They were given either 120 milligrams of proantocyanidin-A (60mg twice a day) or a placebo for 12 weeks. Before, during, and after the study, bacterial factors were assessed that included the growth, adhesion, biofilm formation, urinary pH, and resistance of E. Coli within the urinary system. Minimum bactericidal concentration and bacteria adhesion were also measured (7).
After 12 weeks, researchers noted the following:
| 6 weeks | 12 weeks | |||
|---|---|---|---|---|
| UTI Factors (Against E. Coli) | Group 1: Cranberry Extract, 120mg | Group 2: Placebo | Group 1: Cranberry Extract, 120mg | Group 2: Placebo |
| Bacteria Growth | 72.7% Decrease. (33 to 9) p<0.001* | 11.1% Decrease (36 to 32) Not Significant | 75.8% Decrease (33 to 8) p<0.001 | 2.8% Decrease (36 to 35) Not Significant |
| Bacteria adhesion | 80.1% Decrease. (2.1 to 0.42) p<0.001 | 1.4% Increase (1.22 to 1.72) Not Significant | 86.7% Decrease (2.11 to 0.28) p<0.001 | 86.7% Decrease (2.11 to 0.28) p<0.001 |
| Biofilm Formation | 87.5% Decrease. (8 to 1) p<0.001 | No Change (6/6) | 62.5% Decrease (8 to 3) p<0.018 | No Change (6/6) |
| MRHA (resistance) | 91% Decrease (33 to 3) p<0.001 | 8.6% Decrease (35 to 32) Not Significant | 97% Decrease (33 to 1) p<0.001 | 5.7% Decrease (35 to 33) Not Significant |
*p<0.001 = significant
In addition, UTI factors measured at 3 weeks were not significant in both groups, although the cranberry extract group revealed a slight decrease. Group 1 also decreased urinary pH levels (6.28 to 5.88) for an optimal environment to prevent bacterial growth.
When suggesting how cranberry extract (proantocyanidin-A) benefits those with recurrent UTI’s, the researchers pointed to proantocyanidin-A’s strong antimicrobial (8, 9, 10) effect to prophylactically reduce E. Coli adherence to uroepithelial cells, and its inhibitory properties for drug-resistant strains of E. Coli (11, 12).
Source: Singh, Iqbal, Lokesh Kumar Gautam, and Iqbal R. Kaur. “Effect of oral cranberry extract (standardized proanthocyanidin-A) in patients with recurrent UTI by pathogenic E. coli: a randomized placebo-controlled clinical research study.” International urology and nephrology 48.9 (2016): 1379-1386.
© Springer Science+Business Media Dordrecht 2016
Posted October 17, 2016.
References:
- “Urinary Tract Infection/Recurrent UTI’s” posted on the Mayo Clinic website.
- Zafriri D, Ofek I, Adar R, Pocino M, Sharon N (1989) Inhibitory activity of cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eucaryotic cells. Antimicrob Agents Chemother 33:92–98
- “Acute and Chronic Bacterial Cystitis” posted on Cleveland Medical Clinic, Digestive Disease & Surgery Institute website.
- “Urinary Tract Infection” posted on the Centers for Disease Control and Prevention website.
- “Treatments for UTI’s” posted on the Centers for Disease Control and Prevention website.
- Singh I, Gautam L, Kaur I. Effect of oral cranberry extract (standardized proanthocyanidin-A) in patients with recurrent UTI by pathogenic E. Coli: a randomized placebo-controlled clinical research study. Int Urol Nephrol (2016) 48:1379-1386. doi: 10.1007/s11255-016-1342-8. Epub 2016 June 17.
- Clinical and laboratory Standards Institute. Methods for dilution Antimicrobial Susceptibility Tests for Bacteria that grow Aerobically; approved Standard- Ninth edition. CLSI Document M07- A9, Wayne, PA: Clinical and Laboratory Standards Institute; 2012
- Grabe M, Bjerklund-Johansen TE, Botto H et al (2012) Guidelines on urological infections. Eur Assoc Urol. http://www. uroweb.org/fileadmin/tx_eauguidelines/2009/Full/Urological_ Infections.pdf. Accessed on 1st Jan 2013.
- Ofek I, Mirelman D, Sharon N (1977) Adherence of Escherichia coli to human mucosal cells mediated by mannose receptors. Nature 265:623–625.
- Gupta K, Scholes D, Stamm WE (1999) Increasing prevalence of antimicrobial resistance among uropathogens causing acute uncomplicated cystitis in women. JAMA 281:736–738.
- \Howell AB, Botto H, Combescure C et al (2010) Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study. BMC Infect Dis 10:94
- Gupta A, Dwivedi M, Mahdi AA et al (2012) Inhibition of adherence of multi-drug resistant E. coli by proanthocyanidin. Urol Res 40:143–150
