03:53 PM PDT on Tuesday, May 30, 2006

By Stephen Swanson

CORVALLIS, Ore. - A chief ingredient in beer shows potent promise in preventing prostate cancer and prostate enlargement, according to a new study by Oregon State University researchers.

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The research, published in a recent issue of Cancer Letters, shows that xanthohumol, a compound found in hops, inhibits NF-kappaB protein in cells along the surface of the prostate gland, said Emily Ho, assistant professor of nutrition and exercise sciences in OSU's College of Health and Human Sciences and a researcher with OSU's Linus Pauling Institute.

The protein acts like a signal switch that turns on a variety of animal and human malignancies, including prostate cancer. "We've shown that the addition of xanthohumol in a cell culture blocks the signal of NF-KappaB protein and works to slow down the growth of benign prostatic hyperplasia and malignant prostate cancer cells," Ho said.

Xanthohumol, which belongs to a group of plant compounds called flavonoids, can also trigger programmed cell death, which plays a role in cancer prevention, as uncontrolled cell reproduction is a cause of cancer.

But don't rush out to stock the refrigerator. Xanthohumol is present in such small amounts that a person would have to drink more than 17 beers to consume the same amount found effective in the study, Ho said.

There are already a number of food supplements on the market containing hops, and scientists in Germany have developed a beer that contains 10 times the amount of xanthohumol as traditional brews. The drink is being marketed as a healthy beer, but research is still under way to determine if the liquid has any impact against cancer. The beer is being microbrewed and is not available outside Germany, but Stevens said he managed to taste a sample.

"It tastes good," he said. "It has a bit of a fresh taste."

While the research is promising, Ho cautions that further study is necessary.

"The one caveat is that all our work is done in a laboratory system using cultured cells with purified compounds," she pointed out. OSU College of Health and Human Sciences