Once upon a time…
…there was a press release with the title “Does Cranberry Juice Treat a UTI? Not the kind you buy at grocery stores, at least” created by Texas A&M.
The press release writer found a medical journal article on cranberry juice capsules reducing the number of urinary tract infections in women at risk for UTI. She then interviewed a urology professor there about this article, cranberry juice and UTI. The urologist was not involved in the research done on the medical journal article. The writer shared the press release on Newswise, “A free newswire for journalists. A press release distribution service for public relations professionals.”
A large number of other online media outlets used this press release and relied heavily on it. This press release came out in February 2016. A Google search [April 22] of the terms: “cranberry juice and UTIs February 2016” and “cranberry juice and urinary tract infections February 2016” resulted in 19,600 sites and 58,100 sites respectively that utilized this press release. One news outlet was The Huffington Post.
Meanwhile Medivizor did a summary of the same medical journal article (American Journal of Obstetrics & Gynecology) as the press release. It is called “Cranberry juice capsules and urinary tract infections.” Medivizor shared the summary on Twitter April 17, 2016.
— Medivizor (@medivizor) April 17, 2016
Graham MacKenzie had read the Huffington Post article titled “Cranberry Juice Won’t Get Rid of Your UTI: Mom Was Wrong,” by Kate Bratskeir as well as Medivizor’s summary. Then Graham tweeted this question.
— Graham MacKenzie PhC (@grahamcmackenzi) April 18, 2016
Here is the answer…
The Moral of the Story
When it comes to health information on the Internet, it’s all in the details.
To get everyone reading this up-to-speed, here is a brief explanation of urinary tract infections and cranberries.
Urinary Tract Infections or UTIs
To understand cranberries and their possible impact on UTIs, we have to know a little about the bacteria that cause urinary tract infections. Between 75% and 95% of urinary tract infections are caused by strains of E.coli. There are other types of bacteria that can cause the infection but this is the most common.
Some people are more susceptible to UTI. Most UTIs occur in women between age 20 to 50: four times as many women as men get UTIs. (Though after age 50, the difference in the numbers of men versus women who get UTIs is reduced. ) Others who are at risk are people with MS, spinal cord injuries, and other nerve damage, people with diabetes, people who have issues with the flow of urine and those who need to use a catheter (tube) to drain urine from their bladder.
One of the features of these bacteria is that they stick to the cells lining the bladder (epithelial cells). This ability to adhere to those cells is key. Keeping these bacteria from adhering to the cells could prevent infections. This is where cranberries come in.
Cranberries, Cranberry Juice and Cranberry Juice Pills
Cranberries contain some unique compounds with impacts on health that are still being uncovered. One component is proanthocyanidins, specifically A-type (there are also B-type). The A-type proanthcyanidins (PACs) have been shown in lab studies to interfere with E.coli attachment to cells lining the bladder.
In a review of controlled trials published in 2012 in the Archives of Internal Medicine found protective effects of cranberry products–protective effects meaning preventive against UTIs. Another review published in 2012 found a “a small trend towards fewer UTIs in people taking cranberry product compared to placebo or no treatment but this was not a significant finding.”
The important piece to know is that you cannot treat an ongoing infection with cranberry products. When you have the infection, the bacteria have already attached to the epithelial cells that line the bladder and have grown.
Now Let’s Look at the Details
Is this a tale of two conflicting stories? Nope. But there is opportunity for confusion.
The Huffington Post story contains a paragraph about the article that Medivizor summarized. What was important about this research study in the American Journal of Obstetrics & Gynecology? Let’s look at the summary by Medivizor.
” This trial investigated the effectiveness of cranberry juice capsules in preventing UTIs among women after surgery and catheter use.”
This is a study about preventing UTIs in women at high risk for them.
An important statement that was in the press release but left out of the Huffington Post article: “For a UTI to occur, bacteria must adhere to and invade the lining of the bladder,” Boone [urologist they interviewed] said. “PACs interfere with the bacteria’s ability to bind to the wall of the bladder and create an infection.” In other words, once the bacteria have stuck to the bladder wall and started multiplying–a urinary tract infection has occurred. Treatment with antibiotics is needed.
“Women were randomized to receive cranberry juice capsules for 6 weeks after surgery, or a placebo (sham treatment used as control). The rates of UTI following surgery were followed and compared between the two treatment groups.”
“UTI rates were significantly lower in the cranberry juice capsule treatment group compared with the placebo group.”
The results supported the hypothesis of the study.
The Fine Print
“This study involved only a small group of women, at a single institution, with a very high risk of developing UTI after catheter use. Results should therefore be interpreted carefully, and may not apply to women at risk of UTIs due to other causes.”
One feature of a Medivizor summary, The Fine Print, is provided to help readers understand the quality of the study and the information that is provided by the study. This is one of the many ways Medivizor helps deal with Graham’s concern about “the struggle with the Internet for health education.”
Choose Your Health Education Sources Carefully
What do you need to do to figure out the right websites for health information so that you are an informed healthcare consumer?
Look At Credentials
If you can, look up the writer of the online article on LinkedIn. Does the writer of the post have a degree in health, public health, nutrition or a medical degree? Is the person a science writer or a credentialed medical writer? Educational background can make a world of difference in effectively researching and understanding a topic in healthcare.
Look At Credibility of Sources
Look for health information that is juried or peer-reviewed.
The sources of content for Medivizor are peer-reviewed medical journal articles. What is a peer-reviewed article?
Peer-reviewed articles are considered to embody the practices in research in their field. Before an article is allowed to be published, it must meet certain standards. These standards include review of the article by impartial experts in the field. The experts’ job is to look for accuracy, validity and rigor in the research methodology. Articles are rejected if they do not meet these standards.
Watch Out For Press Releases
The purpose of a press release is to interest members of the news media in a story. Press releases are written in the same format as news articles. These are written by public relations professionals with the purpose of getting articles written about their organization. A press release may use sensational language to increase the likelihood of “going viral.” The purpose of the press release is publicity, not education.
In Texas A&M press release, the writer stated that
“Unfortunately, PACs aren’t present in cranberry juice at all—only in cranberry capsules.”
Additionally Dr. Timothy Boone is quoted as saying , “the active ingredient in cranberry is long-gone by the time it reaches your bladder.”
Yet a February 2016 article in the Archives of Biochemistry and Biophysics contradicts these two statements. One of the active ingredients of cranberries IS present in cranberry juice. And it makes it to the urinary tract of the body. In the study, healthy young men consumed cranberry juice containing 787 mg of polyphenols. Researchers found that the PACs and other polyphenols were in the plasma (part of the blood) and the urine of the men who consumed the juice. Another 2015 study discusses the presence of digested cranberry components (metabolites) in urine and their ability to interfere with bacteria adhering to the epithelial cells.
The Bottom Line
Details matter a lot in interpreting medical science and health content on the web.
Content on the Internet, including health content, is unregulated. Therefore an attitude of “buyer beware” is called for. Additionally, a search on Dr Google may feel a lot like the game of Chinese Whispers. Every time something is repeated, it becomes more distorted from the original.
Medical science and the peer review strategy reduces distortions like this because research studies build on previous research. Experts make sure that the studies are rigorous.
In the end, what most research on cranberries and cranberry-containing products and the prevention of urinary tract infections agree upon is that larger, well-designed trials are needed.
For Further Reading On Health Information
In previous posts we have recommended valid sources of health information.
- 5 Tips for Deciphering (and Finding) Reliable Online Health Content at https://medivizor.com/blog/2016/04/24/five-tips-deciphering-online-health-content/
- 16 Insights on a Worldwide Chat on Health information Seeking at https://medivizor.com/blog/2015/02/06/16-insights-worldwide-chat-health-information-seeking/
- What does Breakthrough or Miracle Mean in Health News at https://medivizor.com/blog/2015/11/16/groundbreaking-breakthrough-miracle-really-mean-health-news/
- 9 Tips for Sharing Information with Your Doctor at https://medivizor.com/blog/2014/07/22/9-tips-sharing-information-doctor
- 3 Myths about Dietary Supplements https://medivizor.com/blog/2016/03/29/three-myths-vitamins/ 3 myths about dietary supplements