Some people with MS are prone urinary tract infections (UTIs). As such, cranberry juice, a common remedy for UTIs, is of possible interest to those with MS. Cranberry juice has long been used for both treating and preventing UTIs. Until the 1970s, it was believed that cranberry juice increased the acidity of urine, which was thought to destroy bacteria. It is now believed, however, that fructose and proanthocyanidins (a class of chemicals) in the cranberry juice prevent bacteria from attaching to the lining of the urinary tract. Cranberry juice may also kill certain bacteria.
The limited clinical studies available suggest that cranberry juice may be protective against UTIs in some people. Those who appear to benefit in these studies have normal bladder function. These benefits do not appear to be seen with in those with abnormal bladder function, which may occur in MS. More rigorous studies still need to be conducted to examine the effectiveness of cranberry, and how it compares to antibiotics.
UTIs may lead to very serious complications, especially in people with MS. Cranberry juice should not be used for treating these infections; people need to use conventional antibiotics. However, it may be reasonable for people to use cranberry juice as a preventative measure against UTIs.
Exact dosing recommendations have yet to be established. Dosages may be around 1 to 10oz. of juice, 6 capsules of dried powder, or 0.5 to 5oz. of fresh or frozen cranberries. Some people find it difficult to eat cranberries, fresh or frozen, due to the sour taste. Cranberry juice cocktail is only about one-quarter to one-third juice.
Generally, cranberry is well tolerated. It is possible for cranberry to interact with blood-thinning medication. Long-term use of large amounts of cranberry may result in nausea, stomach discomfort, loose stools, or kidney stones. It is not known if cranberry is safe for pregnant women or women who are breast-feeding.
Bearberry and vitamin C are also sometimes recommended for UTIs. Bearberry, or uva ursi, is not clearly effective for preventing UTIs. Furthermore, it may cause nausea or vomiting. Bearberry also contains certain chemicals that may be carcinogenic. As for vitamin C, clinical studies do not support the belief that it is effective for treating or preventing UTIs. Also, vitamin C may cause kidney stones and stimulate the immune system. (See the Vitamin A, C, and E section of the Vitamins, Minerals, and Other Non-herbal Supplements page for more information.)
References and Additional Reading
Bowling AC. Complementary and Alternative Medicine and Multiple Sclerosis. New York: Demos Medical Publishing, 2007.
Bowling AC, Stewart TS. Dietary Supplements and Multiple Sclerosis: A Health Professional’s Guide. New York: Demos Medical Publishing, 2004.
Jellin JM, Batz F, Hitchens K, et al. Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Faculty, 2009.
Ulbricht CE, Basch EM, eds. Natural Standard Herb and Supplement Reference: Evidence-Based Clinical Reviews. St. Louis: Elsevier-Mosby, 2005.