Cranberry juice prevents urinary tract infections; more is better

• You may have heard that cranberry juice helps prevent urinary tract infections.
• Now, research shows that the amount of cranberry juice you drink may determine how much protection you get.
• There's been evidence that cranberry juice and other products can prevent and even treat simple urine infections, and now researchers may have an indication as to how much is needed to better fight bacteria and stop it from infecting the bladder.
• Drinking 8 ounces of cranberry juice more than doubled the protection against infection compared with drinking 4 ounces, according to a recent study by Kalpana Gupta, MD, MPH, of Yale University, and colleagues from the University of Washington and Rutgers University.
• Symptoms include a frequent need to urinate and pain or burning during urination.
• In the study, three volunteers provided urine samples, drank 4- or 8-ounce servings of cranberry juice cocktail, and then provided more urine samples four to six hours after drinking the two different serving sizes of cranberry juice.
• The researchers combined each of the urine samples with human bladder cells and E. coli bacteria.
• Then, they measured the amount of bacteria that latched on to the bladder cells.
• E coli bacteria must anchor itself to the bladder in order to cause an infection.
• Credit likely goes to a specific type of tannin found only in cranberries and blueberries.
• The study used 27% cranberry juice, according to the IDSA news release.
• Blueberries need further testing to see if they work as well at preventing UTIs as cranberries, which have been used in traditional Native American medicine to treat urinary problems.
• The findings were presented in Boston at the 42nd annual meeting of the Infectious Diseases Society of America.