Cranberries: a fruity
option for UTIs?
Urinary tract
infections (UTIs) are among the most common bacterial infections in adults
today, affecting 150 million people worldwide. Gram-negative bacteria are
responsible for most community-acquired and hospital-acquired UTIs. Strains of
Escherichia coli that are harmful for the urinary tract account for 85–95% of cystitis
cases and 90% of acute pyelonephritis infections, according to a study
performed by the Worcester
Polytechnic Institute published in 2010. However, resistance to the
trimethoprim-sulfamethoxazole antibiotic treatment has been seen in 25% of UTI
cases in the US and in up to 60% of UTI cases in Asia. Alternative strategies toward
prevention of UTIs can be helpful in this regard. The American red cranberry
has been traditionally recognized for its benefits to the urinary tract. Their
study was the first to directly show that Cranberry juice decreases the “sticking”
of E. coli to cells on the urinary
tract. To test the strength of the cranberry juice
"shield," the team of researchers used a tiny probe on the tip of an
atomic force microscope, which has the ability to sense the smallest of
interactions between cells. They measured the strength of the bond between the
bacteria and urinary tract cells in the presence of different concentrations of
juice. The microscope’s measurements showed that as the concentration of
cranberry juice cocktail increased, the force holding a single bacterium to a
urinary tract cell decreased. The researchers concluded that the more cranberry
juice cocktail present, the less ability the E.
coli had to grab onto the cell.
However, another study published in the Archives
of Internal Medicine Journal in 2011 suggests this widely used natural
remedy is considerably less effective than low-dose antibiotics to treat recurrent
UTIs. In this study, 221 premenopausal women with recurrent UTIs
were received 480 milligrams a day of the standard antibiotic treatment for the
condition or 500 milligrams twice a day of some cranberry capsules. Seventy
eight percent of those women taking cranberry capsules had at least one UTI
during the study, versus 71% in the drug group. UTI recurrence also tended to
happen sooner in the cranberry group. The average time to recurrence in the
antibiotic group was about eight months, compared with four months in the
cranberry group. In the other hand, women in the antibiotic group developed antibiotic
resistance. So this is a tough subject, and raises a lot more questions, is
cranberry Juice really effective? And in the other hand, is it more convenient
than antibiotics? Knowing that Antibiotic
resistance is a major public health concern and, most people do not like to
take antibiotics for a long period. I am sure drinking prudent amounts of cranberry
juice will not hurt anyone, so maybe we can come up with a good balance,
consuming this juice as prevention and going to our doctor when we encounter a
major infection.
That is an interesting study you found in the archives of Internal Medicine Journal. I am not surprised that chronic treatment with low dose antibiotics resulted in bacteria that were resistant to those antibiotics.
ReplyDeleteIn animals that develop routine bacterial infections, we assume there is another underlying problem that predisposes them to urinary tract infections. Things like bladder stones, cancer, or anatomical problems.
I also found it interesting that cranberry juice reduces the ability of E. coli to bind to urinary epithelium. I have heard of people using it before, but I assumed it was a method of changing the pH of the urine.
I, too, have heard this statement in occasions before. Has anyone ever found a chemical compound in cranberry juice that could be responsible for this “supposed” benefit? I have also asked myself if this benefit isn’t just due to the amount of liquid consumed. Did anyone test different quantities of cranberry juice rather than different concentrations?
ReplyDeleteOn another note, it is known that treating infections with lose-dose antibiotics leads to a high rate of antibiotic resistance.
In the studies that I have read so far, there has been no mention about what is the compound that could causing the bacteria to be removed from the urinary tract. They only mention that the adhesion force of the bacteria is decreased by the consumption of the juice, but I think that definitively it should be a key finding. It would be also interesting to measure the different amounts of juice and find what the results would be, I didn't find any study talking about it though .The study published in the Journal of Internal medicine points that at a dose of 480 mg of Trimethoprim, amoxicillin, and ciprofloxacin once daily , they found antibiotic resistance.
DeleteThe foundational theory behind drinking cranberry juice for UTIs used to be that it likely makes the urine more acidic, but more recent theories that I have read suggest that specific antioxidants in the cranberries alter the E. coli functioning enough that it cannot attach itself to the lining of the urinary tract and flourish, or that cranberry juice forms some sort of bio-layer over the lining that prevents the bacteria from attaching and multiplying.
ReplyDeleteIn the debate concerning antibiotics and cranberry juice, my opinion is that if an individual at a relatively high risk for developing a UTI likes to drink cranberry juice or doesn't mind taking a cranberry juice concentrate pill, they should out of prevention measures because there is enough evidence supporting that it can be beneficial. If somebody develops a UTI, they should take antibiotics to treat the condition. Good nutrition or nutrition approaches usually work best as prevention measures, but are not an acute treatment in most cases (allergies aside).