Study of Antibiotic Vs. Cranberry Supplements for Recurring UTIs Yields Surprising Results
Posted Aug 06 2011 11:47pm
A study that tested cranberry supplements against antibiotics for the treatment of recurring urinary tract infections yielded some surprising results!
By Colette Bouchez
If you’ve been using nutritional cranberry supplements to keep your UTI (urinary tract infections) under control there is both good news and bad. A new study funded by the Netherlands Organization for Health Research and Development and just published in the Archives of Internal Medicine reports that antibiotics are more effective than cranberries at controlling recurring UTIs. But, the study also showed that antibiotics increase your risk of developing a drug-resistant bacteria - and that could be dangerous or even deadly.
Indeed, while the number of recurring infections was cut in half for those women taking the antibiotic, the benefits of those odds seemed to change when the women were also tested for antibiotic resistance.
After just one month of using the antibiotic TMP-SMX (trimethoprim-sulfamethoxazole), resistance to this drug increased three-fold, to as high as 90.5 percent in some women. Resistance to other antibiotics increased as well. There was only a slight increase in antibiotic resistance in women who used the cranberry supplement.
As such, the study author Dr Mariëlle Beerepoot concluded that the use of antibiotics in the treatment of recurring UTIs “should be weighed against the greater development of antibiotic resistance.”
Cranberries vs antibiotics: Study details
The 12 month study involved 221 pre-menopausal women who reported having 3 or more UTI infections in the previous year. In a double blind study each of the women were assigned to take either one 480 mg capsule of TMP-SMX daily or 500mg of Cran Max, a cranberry extract capsule, twice daily. Neither the participants or the researchers knew which women were taking the drugs and which ones were taking the cranberry extract.
The end goal of the study: To determine the number of symptomatic urinary tract infections in each of the two groups over a period of 12 months; how soon the first infection would occur after starting preventive treatment; and development of antibiotic resistance to the E-coli bacteria responsible for most UTIs.
The study result: When the study code was broken and the results analyzed researchers learned that the women taking the antibiotic treatment developed 1.8 infections over the course of 12 months, compared to 4 infections in the women taking the cranberry extract. The number of women who developed any infection was slightly higher in the cranberry group than in the group taking the antibiotic.
Moreover the women taking the antibiotic took at least 8 months to develop an infection while the women taking the cranberry capsules saw infections occur after just 4 months of treatment.
So while it may appear as if antibiotics are a better choice for preventing recurring UTIs, that assumption changed when researchers also looked at the number of bacteria that became antibiotic resistance.
In the cranberry group, between 23% and 28% had bacteria that were resistant to antibiotic.
In the group taking the antibiotic, nearly 91% were found to have antibiotic-resistant bacteria.
Moreover, after taking the TMP-SMX antibiotic for just one month, these same women also had increased resistance to other antibiotics including trimethoprim, amoxicillin and ciprofloxacin.
After stopping the TMP-SMX antibiotic, resistance levels dropped to baseline.
In the group taking the cranberry capsules, there was no increase in antibiotic resistance.
What this means to you
Essentially, cranberry capsules and antibiotics work in two different ways to reduce the risk of UTIs:
Antibiotics work by killing off the bacteria ( mostly E-coli) that cause the infections.
Cranberries work via natural compounds that prevent the bacteria from sticking to the bladder wall – which is the first step in the development of a UTI infection. So, by interrupting the process that allows the bacteria to stick to the wall, cranberry extracts prevent the bacteria from growing. And this in turn helps reduce the incidence of UTIs.
So, while taking antibiotics to preven infections may net you fewer bouts with a UTI over the first year, over time the antibiotics may no longer work – and you could develop antibiotic resistance to other orgnanisms involved in other types of infections as well, thus leaving you defenseless against many germs.
So, what’s a woman to do? The concensus of opinion appears to be go with the cranberry treatment as the best course of preventive action.
In an accompanying editorial to the study, Dr Bill Gurley, of the University of Arkansas for Medical Sciences, wrote : “Such a marked reduction in antibiotic resistance certainly favors the therapeutic potential of cranberry as a natural UTI preventative.”
Not surprisingly, everyone from the Cranberry Council to the makers of the supplements themselves tend to agree that taking cranberry capsules is the better and safer choice for long term prevention of UTIs.
What the study did not tell us, however, is whether or not you could get similar results from eating cranberries or drinking unsweetened cranberry juice on a daily basis.
Moreover, since the study did not include a third group of women - those who took no preventive treatment - we have no way of knowing how many would have developed recurring infections if they used no preventive means at all.
Important to note:If you are taking antibiotic for a current UTI infection do not stop without checking with your doctor first. The main use of cranberry extract is in the prevention of UTIs and not the treatment of bacteria.