A parallel finding is seen with genetic variants that influence alcohol consumption, alcohol dependence, and esophageal cancer. Large studies of esophageal cancer, a cancer related to alcohol use, identify two genetic variants in alcohol metabolizing genes that influence alcohol consumption and alcohol dependence (ADH1b variant, rs1229984, and ALDH2 variant, rs671) and also contribute to the risk of esophageal cancer (Hashibe et al., 2008; Tanaka et al., 2010). Even after controlling for alcohol consumption in the analyses, the protective effects of these variants for esophageal cancer remain strong. This implies that variants in alcohol metabolizing genes not only reduce alcohol consumption and decrease the risk for alcohol dependence, but also lower the susceptibility to esophageal cancer, perhaps by reducing the carcinogenic effects of alcohol, its metabolites and other toxins.
