While reports in humans are conflicting, with some showing an increased risk, new research by Japanese researchers showed that beer or eating certain components found in the beverage may protect against colon cancer in rats. The study assessed the ability of beer or its components to prevent a type of chemically induced colon cancer in 344 rats. Consumption of beer or malt extract for two weeks reduced the amount of DNA damage that occurred. In addition, beer intake for the full five-week study period reduced the formation of early lesions that can develop into colon cancer.
The researchers also stated that the ability of beer to inhibit these lesions depended on the type of malt, with dark-roasted malts being more effective than pilsner malts. In addition, only freeze-dried beer, not ethanol, had a protective effect. Intake of malt extract also inhibited the early lesions, but consumption of hops extract did not. In a 42-week follow-up study, beer intake was associated with a 22-percent reduction in the tumor rate, including a big plunge in the number of cancers. While this study was in rats, and has not been evaluated in humans, the authors state: “The results suggest that daily moderate consumption of beer may reduce the risk of cancer susceptibility in colon.” However, they also underscore that further studies are needed to verify this and to determine the mechanisms involved.
SOURCE: Nozawa H et al. Intake of beer inhibits azoxymethane-induced colonic carcinogenesis in male Fischer 344 rats. Intern Journal of Cancer 2004.