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Meta-analysis ‘affirms’ cranberries’ role in healthy urinary tract? Depends on the studies

Comprehensive meta-analysis affirms cranberries' role in promoting a healthy urinary tract

Our Review Summary

The release focuses on a recent journal article that reviews the available medical literature concerning the effects of cranberry consumption on preventing urinary tract infections (UTIs). The release tells readers that “healthcare professionals should be telling their patients to have cranberry products as a first step in reducing recurrent UTIs.” However, the release offers little substance to support the claim, and neglects to provide information on the extent of benefits or any information on the underlying studies that were reviewed. The assertion that cranberry products are “a first step” implies cranberries were systematically compared with other interventions for preventing recurrence, and that’s not the case here.


Why This Matters

UTIs are common, unpleasant for patients, and can lead to serious complications. The problem of antibiotic overuse for UTIs as well as other infections, and the resulting development of antibiotic resistance, is also a concern. For these reasons, patients who suffer from recurring UTIs may well want to try relatively inexpensive methods that hold promise for preventing infection. But it’s important for people to make informed decisions, and not to rely on broad, unsupported statements.


Does the news release adequately discuss the costs of the intervention?


The release notes that “cranberry products are low cost,” which is fair enough and is sufficient to earn this a satisfactory rating. The issue of cost is, however, complicated by the fact that the release offers no information on what sort of cranberry products a patient may use. Is one glass of cranberry juice per day sufficient? Does one need to consume the whole berries? Or should patients take over-the-counter cranberry-based supplements? Costs would vary depending on how one chooses to pursue the vague directions discussed in the release.

Does the news release adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

Benefits are not quantified. According to the release, “Authors found a statistically significant risk reduction in repeat UTIs overall, but not significant for any particular subgroup.” But what does “statistically significant risk reduction” mean? Were patients 10 percent less likely to get a UTI? 0.1 percent? Those are both statistically significant, but there’s a world of difference. In fact, the published study reported that the risk of recurrent infection was reduced by approximately 33 percent. Including this quantitative information would greatly strengthen the release.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

The release says only that taking cranberries as a health supplement is “low risk.” And that’s true. But that doesn’t mean that it’s no risk. For example, the University of Maryland notes that one of the chemicals found in cranberries can increase the risk of kidney stones for some people — that’s valuable information for readers who have a history of kidney stones. Even if the harms are minimal, it is important to note that fact explicitly. 

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The release notes that the journal article is a meta-analysis of 28 studies, which involved close to 5,000 patients. That’s good, but not quite good enough — a little more information was needed. For example, what sort of studies are we talking about? How many were randomized controlled trials (the gold standard) and how many were observational? The release doesn’t need to provide details on all 28 studies, but it should tell readers whether any of the studies used placebo, were double-blind, etc.

Does the news release commit disease-mongering?


No disease mongering here. The release refers to a UTI as a “potentially debilitating infection,” but given that UTIs can lead to kidney damage or sepsis, that’s not inaccurate.

Does the news release identify funding sources & disclose conflicts of interest?


This is satisfactory, yet the release could have been more transparent about the organization that issued the release. The study itself was supported by a Portuguese university and a Portuguese bank, which is noted in the release. However, the release lists a PR firm as the contact but includes a quote from the director of the Cranberry Institute and a summary of the Institute as background, without ever mentioning the group’s relationship to the study.  After looking at the Cranberry Institute’s website it’s clear that the trade group has worked with the PR firm previously on news releases. Why not explain the Cranberry Institute’s interest in the research?

Does the news release compare the new approach with existing alternatives?

Not Satisfactory

There are a number of lifestyle changes, in addition to modifying one’s cranberry consumption, that can reduce the risk of UTIs. For example, increasing one’s water intake or changing one’s form of birth control.

In addition, there are medical interventions such as use of vaginal estrogen preparations (for post-menopausal women) and taking an antibiotic preventively after intercourse.

Does the news release establish the availability of the treatment/test/product/procedure?

Not Applicable

The story doesn’t address this, but it can be assumed that most (if not all) readers will be familiar with the availability of products containing cranberries. Ergo, we’ll rate this as not applicable. It’s worth noting that the release gives readers little idea of what sort of cranberry products a patient could — or should — use to lower their risk of a UTI.

Does the news release establish the true novelty of the approach?

Not Satisfactory

This is not the first journal article to review the available research on whether cranberry consumption can help to prevent recurrent UTIs — only the most recent. See, for example, previous reviews from 2012 and 2007. The release does not refer to these previous reviews or make clear how this most recent review article advances our understanding of the subject.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?


As with the conflict-of-interest section, this earns a satisfactory rating, but includes some odd language that is worth noting. First of all, there is no unjustifiable language in regard to the study itself — thus the satisfactory rating. However, the release also quotes the director of an industry-funded organization, who notes that this research “revitalizes the enthusiasm for cranberry products year-round.” The relevant paragraph comes as a distinct non sequitur and gives the release the tone of an advertisement, rather than an attempt to raise awareness of recent health research findings.

Total Score: 4 of 9 Satisfactory


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