Cranberries combat urinary tract infections

Jan 11 2008

Cranberry juice, long dissed as a mere folk remedy for relieving urinary tract infections in women, is finally getting some respect.

Thanks to Prof. Itzhak Ofek, a researcher at Tel Aviv University's Sackler Faculty of Medicine, the world now knows that science supports the folklore. Prof. Ofek's research on the tart berry over the past two decades shows that its juice indeed combats urinary tract infections.

And, he's discovered, the refreshing red beverage has additional medicinal qualities as well. Prof. Ofek has found that cranberry juice exhibits anti-viral properties against the flu, can prevent cavities, and lessens the reoccurrence of gastric ulcers. Unhappily for half the human race, however, new research published this year in the journal Molecular Nutrition & Food Research on ulcers, suggests that, like urinary tract infections, the healing power of cranberries apply only to women.

The remarkable healing property in cranberries stems from a heavy molecule known as non-dialyzable material or NDM. This molecule, isolated by Prof. Ofek and his colleagues, seems to coat some bodily surfaces with Teflon-like efficiency, preventing infection-causing agents from taking root.

Surprisingly, NDM appears to have no effect on some of the good bacteria in our bodies, says Prof. Ofek. His seminal research on the subject, in collaboration with Prof. Nathan Sharon from the Weizmann Institute, appeared in the world's leading medical journal, the New England Journal of Medicine, in 1991. “We understood that there was something in cranberry juice that doesn't let infections adhere to a woman's bladder," Prof. Ofek says. "We figured it was a specific inhibitor and proved this to be the case.”

After the 1991 study, Prof. Ofek conjectured that if cranberries could protect against bacterial invasion in the bladder, "Could they work wonders elsewhere"” He took the question Tel Aviv University's School of Dental Medicine, and together with Prof Ervin Weiss, produced positive results.

“We found that NDM inhibits adhesion of oral bacteria to tooth surfaces and as a consequence reduced the bacterial load that causes cavities in the mouth,” says Prof. Ofek. “And after a clinical trial, we formulated a mouthwash based on cranberries which was patented by Tel Aviv University.”

But Prof. Ofek wasn't content to stop at cavities. Working with Prof. Ervin Weiss and Prof. Zichria Rones at Hadassah Medical and Dental School, he found that NDM inhibits the flu virus from attaching to cells and prevented experimental flu infections in animal models.

Most recently, Prof. Ofek collaborated with Dr. Haim Shmuely, a resident physician at the Beilinson Hospital and lecturer at Tel Aviv University, to find that cranberry also inhibits two-thirds of the “unhealthy” bacteria that clings to gastric cells, which lead to ulcers.

“The results were very interesting,” says Prof. Ofek. “Cranberry helped reduce the load of this bacteria, Helicobacter pylori, in the gut. In combination with antibiotics, it reduced repeat ulcers from approximately 15 percent to about 5 percent.”

The one drawback to this research is that it only holds true for women, showing once again cranberry's affinity for the female. “The whole thing with cranberries seems to be female-oriented,” admits Prof. Ofek.

He continues, “The take-home message is that God created this fruit with a polyphenolic material. We still don't know its chemical formula, but it seems to target a fraction of bacteria and viruses.”

Today, a cranberry research team comprised of scientists from across Israel, and headed by Professors Ofek and Weiss, are investigating the berry's healing powers. Recently, it was found that cranberry NDM may also act as an anti-cancer agent. The scientific research methods behind the research have been patented by Tel Aviv University.

Prof. Ofek's recommendation is that women drink two glasses a day to treat certain infections. And because “there is still so much we don't know about cranberries, I would suggest that men also drink two glasses a day,” he concludes.