Cranberry Juice May Prevent Urinary Tract Infections

Women who consume cranberry juice (Vaccinium macrocarpon) on a daily basis may help prevent the urinary tract infections (UTIs), according to a new study in the Journal of the American Medical Association (2002;287:3082–3).

Urinary tract infections are bacterial infections of the bladder that affect women more often than men and can lead to infection in the kidneys if untreated. Antibiotics are recommended by most doctors to treat UTIs, but the incidence of antibiotic resistance has increased dramatically over the last couple of decades. New strategies are now needed to help in the prevention and treatment of a condition that leads to over 11 million physician visits each year in the United States.

Researchers collected urine specimens from 39 women between 18 and 39 years old with confirmed bladder infections with E. coli (the most common cause of UTIs), before and after they had consumed 240 ml (approximately 8 ounces) of cranberry juice. Most of the women had bladder infections that were resistant to antibiotics. A series of test tube studies was then performed to determine whether cranberry juice could prevent the E. coli obtained from the women's urine from sticking to bladder cells.

Urine specimens collected from 80% of the women after cranberry juice consumption prevented E. coli from adhering to bladder cells, whereas none of the urine specimens collected prior to drinking cranberry juice blocked this process. These findings suggest that cranberry juice protects the bladder against E. coli infection, even against strains of E. coli that are resistant to antibiotics. However, it is unknown whether cranberry juice would have the same effect against other types of bacteria that cause urinary tract infections.

Another herbal treatment that may be helpful for UTIs is uva ursi (Arctostaphylos uva-ursi). Studies show that uva ursi is an effective treatment for bladder infections, even if the infection is caused by bacteria other than E. coli. The product used in these studies was a standardized extract containing 400 to 800 mg of arbutin per day. Other herbs that have historically been used by herbalists and may be helpful include goldenseal (Hydrastis canadensis), goldenrod (Solidago sp.), juniper (Juniperus communis) and buchu (Agathosma betulina), but scientific studies have not yet been done to determine whether they are effective. For more specific information on herbal treatments and amounts to take, consult a practitioner of herbal medicine.

It is important to note that most herbal remedies for bladder infections should not be used continuously for more than two weeks. On the other hand, cranberry juice has been safely used for prolonged periods of time. These herbs are also not appropriate to use for kidney infections. If you develop fever, chills, nausea, vomiting, or severe back pain, consult a physician immediately.

Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.

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