The history of natural medicine offers countless myths and legends, both justifying the objections of nay-sayers and intriguing the open-minded in their search for answers to their own health challenges or for their patients. Cranberry juice and its promises for preventing bladder infections have long enticed sufferers to imbibe either the sharp juice or its extracted capsules for centuries. Like many natural remedies, anecdotes and experience supported its claims of efficacy, but not all myths and legends turn out to be truth when tested systematically. In this case, a recent study did demonstrate lower rates of urinary tract infections (UTIs) in women taking cranberry supplements or drinking its juice.
The study, published in Cochrane Reviews, contradicts a study in 2012 analyzing 24 trials which showed no clear benefit. This updated study looked at 50 more recent trials covering nearly 9000 participants and found more promising results. Given the high prevalence of these annoying infections in women, the elderly, and many with chronic bladder issues, such a simple intervention has the potential to help a lot of people.
While antibiotics, sometimes even one dose, can cure these infections, their tendency to recur (requiring yet another round of antibiotics) both frustrates the sufferer and risks developing antibiotic resistance. When the researchers combined the data from these studies in a meta-analysis, they showed that with sufficient cranberry in some form, women with recurring UTIs could lower the recurrence by around a quarter. For children, the recurrence rate seemed to be about 50% lower with similar results for patients with a medical condition putting them at risk for UTIs. The elderly however did not show any improvement in UTI rates nor did pregnant women.
The researchers evaluated these studies for quality and risk of bias in multiple ways to avoid any potential bias for or against the cranberry’s efficacy. Forty-five used placebo-controlled arms. Many used urine cultures for confirmation of whether an infection recurred or not rather than depending on symptom reports. While they tried to determine if any difference existed between different forms of cranberry, that data was not clear and no conclusion on the best form was offered.
As with other similar cases in natural and functional medicine, myths and legends sometimes have validity when studied more systematically. For simple and safe interventions like cranberry, anecdotal experience was enough to recommend these therapies to our patients even before this study. Still, a little vindication for our recommendations from such studies is satisfying. At the same time, we do not want to overplay our newly available evidence and become overconfident. This study just looked at prevention but did not address therapy for an already present UTI. In those cases, we will recommend cranberry based on experience and this study, but generally add other natural therapies like garlic, uvi ursi, or colloidal silver to our protocols, as the cranberry does not always put out the UTI fire by itself. Helping our patients live healthier more abundant lives requires both evidence like this study as well as the wisdom to apply such evidence.
Primary Reference:
Gabrielle Williams, Deirdre Hahn, Jacqueline H Stephens, Jonathan C Craig, Elisabeth M Hodson. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews, 2023; 2023 (4) DOI: 10.1002/14651858.CD001321.pub6
Thanks to Science Daily:
Flinders University. “A myth no more: Cranberry products can prevent urinary tract infections for women: New medical evidence shows consuming cranberry products is an effective way to prevent a UTI.” ScienceDaily. ScienceDaily, 20 April 2023. <www.sciencedaily.com/releases/2023/04/230420080722.htm>.
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.
