Lots of chemicals found in beer have shown promise in preventing or even treating cancer — although studies so far have been in Petri dishes and rodents. One type of bitter acid, lupulone, wiped out tumors in rats with colon cancer who consumed it in their drinking water, according to a 2007 study published in Carcinogenesis. Xanthohumol, another beer ingredient, also looks promising. A 2010 study by an Austrian research team found that xanthohumol shut down abnormal cell growth and prevented DNA damage in rats exposed to cancer-causing chemicals. The researchers say xanthohumol is likely to be good for humans too, since its cancer-fighting effects were seen at relatively low doses — equivalent to what people would get with moderate beer consumption.