Effect of Cranberry Pills to Prevent and Treat Urinary Tract Infection among Persons with Spinal Cord Injury

In 1998, the University of Alabama at Birmingham received federal funds for the Rehabilitation Research and Training Center (UAB-RRTC) on Secondary Conditions of Spinal Cord Injury. One of the purposes of the UAB-RRTC is to conduct research and provide a means for dissemination of research results. Results from these research activities are now available.

One area of research focus includes urological issues to improve the general health and well-being of individuals with spinal cord injury (SCI). Over the years, there has been a lot said about the use of cranberry juice to treat and reduce the incidence of urinary tract infection (UTI). However, there was no previous research activities to test this theory in individuals with SCI.

The source of UTI is bacteria. Bacteria are a group or colony of tiny, microscopic single-celled life forms that live in the body. These bacteria can quickly multiply and lead to disease or infection.

It is normal for most individuals with SCI to have bacteria in their urine that can be identified by a urine culture. However, the bacteria are usually not considered a medical problem unless the individual shows signs or symptoms of illness. This study is important because the presence of bacteria puts individuals with SCI at an increased risk for developing UTI. In fact, complications due to UTI are the #1 medical concern and more likely to affect the overall health and health care costs of individuals with SCI.

Objective

This research project looked at the effectiveness of cranberry pills to reduce or kill bacteria found in the urine of individuals with SCI.

Participants

All participants in this study were individuals with SCI who were living at home, more than 1 year post injury and managing their neurogenic bladder through intermittent catheterization or condom catheter. Participants did not receive antibiotics for 7 days prior to enrollment, and they could not take antibiotics, drink cranberry juice, or do anything to prevent a UTI during their participation in this study.

Methods

Each participant was randomly placed into 1 of 2 groups. One group was given a pill with the cranberry extract, and the other group was given a placebo (sugar) pill. A laboratory test verified that the cranberry abstract contained the presumed active ingredient of cranberry juice. Participants were asked to take 2 pills in the morning and 2 pills at night with water for 6 months. Neither the researchers nor participants knew who was taking the cranberry extract or placebo.

Participants provided urine samples at the time of the initial clinic visit and monthly for 6 months. Microbiological data were evaluated using analysis of variance with repeated measures. All participants showed more than 10,000 bacterial colonies per milliliter of urine when first enrolled in the study.

Results

There were 23 individuals with SCI who received the cranberry extract while another 20 individuals with SCI received placebo. There were no differences or trends detected over time between the two groups with respect to number of urine specimens with 10,000 bacteria colonies per milliliter, types and numbers of different bacterial species, numbers of urinary leukocyte counts or urinary pH.

Conclusion

This study did not show that cranberry pills offer any benefit in reducing the number of bacteria in the urine of individuals with spinal cord injury.