Cranberry Juice Capsules Ineffective in Reducing UTIs in Older Women Interview with:

Manisha Juthani-Mehta, MD, FACP, FIDSA, FSHE</strong>A Associate Professor, Section of Infectious Diseases Infectious Diseases Fellowship Program Director Yale University School of Medicine

Dr. Manisha Juthani-Mehta

Manisha Juthani-Mehta, MD, FACP, FIDSA, FSHEA
Associate Professor, Section of Infectious Diseases
Infectious Diseases Fellowship Program Director
Yale University School of Medicine What is the background for this study? What are the main findings?

Response: One of the first studies that showed that cranberry juice was effective in older women living in nursing homes and assisted living facilities was published in 1994. Since that time, there have been multiple conflicting studies as to the effect of cranberry juice or capsules. We started our study in 2012. Shortly thereafter, a Cochrane review suggested that the vast body of evidence did not suggest that cranberry products work for UTI prevention, but questions still existed as to whether the appropriate dose of cranberry was being tested. Since cranberry juice is hard for older women to drink (taste, sugar load, volume), capsules at a high dose of the active ingredient (72mg type A proanthocyanidin [PAC}) was worthwhile to test.

This study was a clinical trial of two cranberry capsules with a total of 72mg of proanthocyanidin (pac) vs two placebo capsules to prevent bacteria in the urine of older women who live in nursing homes.

Unfortunately, it didn’t work. It also didn’t reduce the number of hospitalizations, deaths, antibiotics used, or antibiotic resistant bugs in the urine. What should readers take away from your report?

Response: Cranberry products have long been thought to prevent urinary tract infections.

Many different cranberry products including capsules, tablets, and powders are promoted for this purpose but in older women, this study did not show that this product, with a very high pac content, worked.

Hydration is likely the most important thing to prevent urinary tract infections. Older women can also try to remain clean and dry. For older women on fixed incomes, spending discretionary funds on cranberry capsules may not be worthwhile. Also, there are so many capsules with variable pac content on the market that it is hard for consumers to figure out what to purchase.

Many people firmly believe in their cranberry product of choice, and to those people, I tell them to continue what they feel works for them. There certainly seems to be little downside to drinking cranberry juice if you like it. What about for younger, healthier women?

Response: Most studies over the last twenty years in older and younger women have not shown that cranberry products work. A recent Cochrane review that reviews all studies on cranberry did not suggest that it works in any population. PAC, a type of tannin, high in content in cranberries is thought to prevent the common E.coli bacteria from binding to the bladder wall. Those studies that have shown a benefit have all had large volumes of fluid as part of the intervention, either juice or water. So many believe that it is the hydration that is most important. This study is another in a long line of studies that don’t suggest that cranberry products work to reduce UTI. Thank you for your contribution to the community.


Juthani-Mehta M, Van Ness PH, Bianco L, Rink A, Rubeck S, Ginter S, Argraves S, Charpentier P, Acampora D, Trentalange M, Quagliarello V, Peduzzi P. Effect of Cranberry Capsules on Bacteriuria Plus Pyuria Among Older Women in Nursing Homes
A Randomized Clinical Trial. JAMA. Published online October 27, 2016.


Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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