TO THE POINT: Rutgers Researchers Find E. coli Inhibitor in Cranberries; Compounds Isolated in Cranberries Key to Urinary Tract Health.

NEW BRUNSWICK N.J. and PISCATAWAY, N.J.--(BW HealthWire)--Oct. 7, 1998--In a landmark study, scientists have pinpointed why drinking cranberry juice may be an effective strategy to help ward off urinary tract infections - an often reoccurring, painful problem that accounts for more than seven million doctor visits annually. Published in a letter in the October 8th edition of The New England Journal of Medicine, the research is the first to document the specific components in cranberries that promote urinary tract health.

Led by a team from Rutgers, the State University of New Jersey, the scientists isolated compounds called condensed tannins or proanthocyanidins from cranberry fruit, which were found to be capable of preventing Escherichia coli (E. coli) bacteria from attaching to cells from the urinary tract. E. coli are the primary bacteria responsible for urinary tract infections.

"We already know from previous reports that cranberries have a beneficial effect on urinary tract health," said Amy B. Howell, Ph.D., research scientist at Rutgers and lead investigator of the study. "This breakthrough study is the first to identify what's actually responsible for the effect. We found that the condensed tannins in cranberries were capable of preventing the bacteria from attaching to the urinary tract, which would promote flushing of bacteria from the bladder into the urine stream, resulting in the prevention or reduction of symptoms."

The Rutgers researchers believe the cranberry compounds may act by blocking or preventing growth of the part of the bacteria that bind to the urinary tract and lead to infection. Howell estimates that the amount of condensed tannins in a 10-ounce glass of cranberry juice cocktail consumed on a daily basis would help prevent E. coli from attaching to the walls of the bladder and kidney and ward off urinary tract infections.

Urinary tract infections - including cystitis or bladder infections - are caused by bacteria adhering or sticking to the walls of the bladder and kidney. The urinary tract is routinely cleansed of bacteria through the elimination process, but an infection can develop if the bacteria adhere to the cell walls and multiply. About one-quarter of the women in this country are estimated to have had at least one urinary tract infection in their lifetime. Many are plagued by persistent infections that often require ongoing treatment with antibiotics.

There has been heightened interest in cranberry as a treatment for urinary tract infections since a 1994 Harvard Medical School study published in The Journal of the American Medical Association found that regular consumption of cranberry juice cocktail significantly reduced the bacteria associated with urinary tract infections for the women, average age of 78, who participated in that study. While it had been long suspected that there was a connection between cranberry juice and urinary tract health, this study provided the clinical evidence to document the claim. Previous reports suggested that cranberry juice may help make the urine more acidic, but the Harvard study concluded that there was something specific to the cranberry that prevented bacteria from adhering to the lining of the bladder.

The current study helps confirm this anti-adherence theory and is the first to identify the specific components in cranberries that prohibit the bacteria from sticking to cells from the urinary tract. The compounds in cranberries were isolated by a process called bioassay-directed fractionation at the Rutgers Blueberry and Cranberry Research and Extension Center in Chatsworth, N.J. The isolation process took nearly five years to complete. Additional team members include Nicholi Vorsa, Ph.D., research professor at Rutgers, Ara Der Marderosian, Ph.D., from The University of the Sciences in Philadelphia and Lai Yeap Foo, Ph.D., of Industrial Research Limited in New Zealand.

"This pivotal study adds another vital piece to the puzzle of why cranberry promotes urinary tract health," said Martin Starr, Ph.D., director of health and nutrition at Ocean Spray Cranberries, Inc., which provided research funding to Rutgers. "The discovery helps validate what was once medical folklore, confirms the urinary tract benefits of drinking cranberry juice and identifies what is responsible."

Other members of the same botanical family as cranberries, including blueberries, contain these condensed tannins and exhibited similar bacterial anti-adherence activity. Other common fruits and vegetables that were tested - including lemons, oranges, apples, bananas, carrots, lettuce and potatoes - did not have this activity.

According to James Roberts, M.D., professor of urology at Tulane Medical Center, "Urinary tract infections affect so many women and frequently the infections are recurrent. If we can offer women an option to change their diet, incorporate cranberry juice more often, then we could potentially prevent this painful problem before it occurs."

NOTE: B-roll footage will be distributed via satellite from 2:00-2:30 p.m. ET on Wednesday, Oct. 7. Coordinates are TELSTAR 4 (C-BAND) TRANSPONDER 6. Dual audio 6.2/6.8. Hard copies of the videotape are available upon request. A photograph of Howell and Vorsa is available in a downloadable version at http://ur.rutgers.edu/medrel/news/envstud/berries.html.

The Rutgers Blueberry and Cranberry Research and Extension Center, established in 1962, generates and disseminates research information directly applicable to the production of high-quality blueberries and cranberries and develops new cultivars for industry.