Medical Benefits of Cranberries

In the U.S., most people commonly associate cranberries with the celebration of Thanksgiving and Christmas and consume the product in the form of cranberry juice or cranberry jam. What these people probably never realized was the apparent medical benefit of the cranberry crop. According to a study in the Journal of the American Dental Association (December), certain compounds in cranberries inhibit some bacteria from adhering to each other and producing dental plaque, a major cause of disease. The study was conducted at Tel Aviv University, Israel, by a group of researchers who were among the first to identify the bacterial anti-adhesion benefits of cranberries in maintaining urinary tract health.

As mentioned, cranberries have the ability to be a "good preventive maintenance" against urinary tract infections. The scientific rationale used to be that highly acidic cranberry juice alters the urinary tract's acid-alkaline balance. That's not the reason says microbiologist Anthony Sobota of Ohio's Youngstown State University. A January 1991 issue of Cosmopolitan, states that a specific molecule found in cranberries surrounds the cystitis-causing bacteria, preventing them from invading cell membranes. The germs, rendered harmless, get flushed out in urine. The article continues and states that antibiotics are still usually necessary for extreme cases, but says Sobota, "for women who have chronic infections, cranberry juice appears to be good preventive medicine."

A New York Times article acknowledges the aforementioned finding. The article states that new research studied seven fruit juices to see if they contained compounds known to prevent bacteria from sticking to the wall of the urinary tract and causing infection. Cranberries and blueberries had the compounds. Grapefruit, guava, mango, orange, and pineapple juices did not. In a November issue of Cranberries, these compounds are specifically mentioned. Scientists, led by a team from Rutgers University, the State University of New Jersey, 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. Amy B. Howell, Ph.D., research scientist at Rutgers and lead investigator of the study, states that the team 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 systems."

There has been heightened interest in cranberries 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 significantly reduced the bacteria associated with urinary tract infections for the women, average age of 78, who participated in the study. 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. Martin Starr, Ph.D., director of health and nutrition at Ocean Spray Cranberries Inc., states that "this pivoted study adds another vital piece to the puzzle of why cranberry promotes urinary tract health.

"Cystitis and the Curative Cranberry." Cosmopolitan. Jan. 1991.
"Fruit Juice and Infection: Preventive Effect Confirmed." New York Times. Tues. Jan. 21st, 1991.
"Study Helps Confirm Anti-Adherence Theory." Cranberries. Nov. 1998, p.27.
Journal of the American Medical Association
Journal of the American Dental Association

Shariq S. Khwaja and Akhtar Khwaja
K Laboratories International