Urinary tract infection
(UTI), is a pretty common bacterial infection (most
often caused by Escherichia coli
that can occur anywhere in the urinary tract
- urethra, ureters, bladder or
kidneys. It is 10 times more common in women than in men and statistics reveal
that more than 50 percent of women get UTI at least once in their lifetime. Being
female, being sexually active or using certain types of birth control,
menopause, diabetes, and using a catheter to urinate, are all risk factors for
Although UTI can be successfully
treated with a short course of oral antibiotics
, the most studied and most
effective natural remedy for the infection is the cranberry
, in the form of
juice, sauce, or dried fruit.
Cranberry Juice and Urinary Tract Infection
Earlier, scientists believed that
cranberry juice improved urinary tract health by lowering the pH of the urinary
tract and making it more acidic. However, more recent research studies have
shown that antioxidants called proanthocyanidins (PAC) present in cranberry
prevents E. coli
from sticking to the
urinary tract walls. And this goes for both, antibiotic-susceptible and
antibiotic-resistant E. coli
The mechanism by which cranberry
PACs altered bacterial behavior, however, was not fully understood until Dr.
Nathalie Tufenkji and her team from the Department of Chemical Engineering at
McGill University in Montreal found that expression of the gene that encodes
for the bacteria's movement was decreased in the presence of cranberry PACs.
They also found that cranberry
powder can inhibit the ability of Proteus
, a bacterium frequently implicated in complicated UTIs, to multiply
and swim in the laboratory medium. Further, increasing concentrations of
cranberry powder reduced the production of urease by the bacteria
. Urease is an
enzyme that contributes to the virulence of infections.
"While the effects of cranberry
in living organisms remain subject to further study, our findings highlight the
role that cranberry consumption might play in the prevention of chronic
infections," Dr. Tufenkji said. "More than 150 million cases of UTI are
reported globally each year, and antibiotic treatment remains the standard
approach for managing these infections. The current rise of bacterial
resistance to antibiotics underscores the importance of developing another
Findings of another study from
the same team revealed that cranberry-enriched silicone substrates impaired the
spread of P. mirabilis
the potential use for cranberry derivatives to hinder the spread of germs in
implantable medical devices such as catheters.
The most recent research
published in the journal Phytotherapy
confirmed the preventive effect of cranberry on urinary tract infection
Cranberry Juice Benefits
Apart from UTI, a few studies
also suggest that cranberry PACs can prevent Helicobacter pylori
, a bacteria that cause stomach ulcers
sometimes cancer, from sticking to the stomach walls.
Benefits of antimicrobial
activities of cranberry extend beyond the urinary tract and stomach. Studies
have suggested that cranberries have major cardiovascular benefits
, in the sense,
they reduce LDL levels and platelet aggregation, maintain HDL levels and
improve vascular function.
The same PACs in the cranberry
juice that help with UTI also inhibit bacteria from clinging to the teeth, thus
preventing tooth decay
Interestingly, cranberry juice
can help with obesity
too. A study on lab mice from the State University of New
Jersey, USA, showed that cranberry juice supplementation ameliorated insulin
resistance and plasma lipid profile, and reduced visceral fat mass in obese
Cranberry is also beneficial in
type 2 diabetes and prostate cancer.
Cranberry Juice Health Risks
Despite all these benefits of
cranberry juice, there is a flip side to it as well, as far as UTI is
concerned. The National Institutes of Health (NIH) cautions people with
personal or family history of kidney stones
not to drink cranberry juice or use
Although a Cochrane review in
2012 showed that a person had a 14 percent lower risk of UTI if taking
cranberry products compared to no treatment or a placebo, several researchers
pointed out that it was not a 'very significant difference' and could be just
chance. Many also pointed out that positive results obtained under laboratory
conditions may not have the same outcome in human beings.
Again, according to the European
Food Safety Authority - 'A claim on cranberry fruit products by standardized by
their proanthocyanidin content and reduction in the risk of urinary tract
infections in women by inhibiting the adhesion of certain bacteria in the
urinary tract has been assessed with an unfavorable outcome'.
Further, number of case reports
suggested that taking cranberry juice might interact with warfarin (Coumadin).
However, other trials refuted the suggestion by saying taking two 8-ounce glass
of juice daily doesn't interfere with the action of warfarin
Another drawback is that medical
fraternity hasn't come out with equivocal recommendation on how much cranberry
juice to take or which product (juice or tablets) is more effective in treating
Ultimately, even if cranberry
doesn't help you prevent UTI, drinking more fluids including cranberry juice
helps flush out bacteria from the urinary tract. But drink it only if it
doesn't interfere with your medications or doesn't bother your stomach.
Whether or not cranberry prevents
or cures UTI, cranberry juice has big health payoffs because of its antioxidant
content. So go ahead and have a glass just for the pleasure of enjoying it!