Cranberry juice is of relevance because urinary tract infections (UTIs) are common with MS, and cranberry juice has a long history of use in their prevention and treatment. From the 1920s to the 1970s, it was believed that the acid from cranberry juice makes the urine acidic and that this increase in acidity prevents and treats UTIs. However, subsequent studies showed that the effect of cranberry juice was probably due to the presence of two types of compounds, fructose and a class of chemicals known as proanthocyani-dins. These chemicals do not destroy bacteria. Instead, they appear to keep bacteria from attaching to the walls of the urinary tract. As a result, it is believed that bacteria present in the urinary tract are unable to cause an infection and are simply passed in the urine. In addition to these effects, cranberry juice, like antibiotic medications, also may kill some bacteria.
Limited clinical studies indicate that cranberry may prevent UTIs in some people. A beneficial effect has been reported in studies of UTI prevention in women who have normal bladder function. However, limited studies of people with abnormal bladder function, which may occur in MS, indicate that cranberry is not effective for UTI prevention. A rigorous, well-designed study of cranberry use for the prevention or treatment of UTIs has not been done yet. Also, it is not known how the effectiveness of cranberry compares with that of prescription antibiotics, the more conventional method for preventing UTIs.
Because UTIs in people with MS may lead to serious complications, including worsening of neurologic difficulties, cranberry juice should not be used to treat infections. On the other hand, for people interested in an herbal approach, it may be reasonable to attempt to prevent infections using cranberry juice. The exact doses that should be used have not been established. Doses sometimes recommended for prevention are 1 to 10 ounces of juice daily. Six capsules of dried powder or 1.5 ounces of frozen or fresh cranberries may be equivalent to 3 ounces of juice. The use of frozen or fresh cranberries may not be possible because of the sour taste of the berries. Cranberry juice cocktail is 26 to 33 percent juice.
Cranberry generally is well tolerated. Cranberry may interact with blood-thinning medications, including warfarin (Coumadin). The chronic use of high doses may increase the risk of developing kidney stones and may cause stomach discomfort, loose stools, and nausea. The safety of cranberry use in women who are pregnant or breast-feeding is not known.
Another herb sometimes recommended for UTIs is bearberry, also known as uva ursi. Some concerns about this herb exist. Specifically, it is not clearly effective for UTI prevention, it appears to be less effective with acidic urine, it may cause nausea and vomiting, and it contains chemicals that may have cancer-causing properties.
Taking vitamin C supplements is a nonherbal approach sometimes recommended for preventing and treating UTIs. However, clinical studies do not support the use of vitamin C for preventing or treating these infections. Vitamin C may increase the risk of kidney stones in those with a history of kidney stones. A theoretical risk exists that high doses of vitamin C may stimulate the immune system and possibly worsen MS.
Was this article helpful?