Xanthohumol (pronounced zan-tho-HUE-mol) is a flavonoid, a type of antioxidant that may have antiviral, anti-allergic, anti-clotting, anti-inflammatory, and anti-tumor activity. It was first isolated in 1913 from hops, the aromatic herb that flavors beer. More recent studies at the Linus Pauling Institute at Oregon State University (OSU) have found that xanthohumol is active against breast, colon, and ovarian cancer cells - at least in test tube studies. OSU studies also have shown that xanthohumol might help prevent prostate cancer.
But please don't get the idea that beer drinking can prevent cancer. First of all, most beers produced in the United States don't contain much in the way of hops. The exceptions are ale, porter and stout, which have higher levels of hops than the more popular lager and pilsner beers. You would have to consume more than 17 beers to get an amount equivalent to the flavonoid content found effective in an OSU laboratory study investigating the effects of xanthohumol on prostate cancer cells.
Xanthohumol isolated from hops is already being marketed in dietary supplements, although there's no evidence that they are safe or effective. The Germans have developed a “health” beer called Xan that contains 10 times the amount of xanthohumol as traditional brews. It is available only in Germany and is almost twice as expensive as other types of beer. Here, too, there's no evidence that drinking it will protect against cancer.
Andrew Weil, M.D.