Self‐Reported Alcohol‐Associated Symptoms and Drinking Behavior in Three ALDH2 Genotypes Among Japanese University Students

BACKGROUND: Alcohol abuse is one of the most serious health problems among young adults. Nearly half of the Japanese population is sensitive to alcohol due to a genetic polymorphism in low K(m) aldehyde dehydrogenase (ALDH2). In the present study, we investigated the effects of the ALDH2 genotype on both self-reported alcohol-associated symptoms and alcohol drinking behavior among Japanese university students. METHODS: The study subjects were 423 (389 males and 34 females) university students in a medical university. The subjects completed a questionnaire regarding self-reported alcohol-associated symptoms and alcohol drinking behavior. The ALDH2 genotype was determined through digestion of polymerase chain reaction (PCR) products by a restriction enzyme Ksp632I. The frequency of alcohol-associated symptoms generally increased in the order ALDH2*1/*1, ALDH2*1/*2, ALDH2*2/*2 among males. The frequency of those who drink > or = 5 days/week was less than 10% in all genotype groups. However, the frequency of those who drink 1-4 days/week was significantly higher in ALDH2*1/*1 than that in ALDH2*1/*2 and in ALDH2*2/*2. A similar tendency also was observed in females. Mean amounts of alcohol consumption per occasion in the three ALDH2 genotypes stratified by drinking frequency generally increased significantly in the order ALDH2*2/*2, ALDH2*1/*2, ALDH2*1/*1 in both sexes. The proportion of binge drinkers defined by those who drink ethanol of > or = 75 ml per occasion on average also increased in the order ALDH2*2/*2 (0.0%), ALDH2*1/*2 (9.8%), ALDH2*1/*1 (22.1%) among male drinkers (> or = 1 day/month). CONCLUSIONS: We for the first time demonstrated clear associations between the ALDH2 genotype, self-reported alcohol-associated symptoms, and alcohol drinking behavior among Japanese university students.