Excess acetaldehyde in the mouth may explain why alcoholics lacking ALDH-2 have such high rates of cancer of the mouth, throat, and stomach, says study coauthor Mikko Salaspuro of Helsinki University Central Hospital. After giving each volunteer a standard-size alcoholic drink, the scientists found that saliva in the ALDH-2-deficient group contained two to three times as much acetaldehyde as the other group’s saliva did. While heavy drinkers worldwide have a high risk of esophageal cancer, Asian alcoholics also have a high risk of other digestive-tract cancers.