Effect of a small dose of alcohol on driving-related behavior of Japanese who self-reported facial flush and nonflushing.

About half of northeastern Asians lack ALDH2 (Acetaldehyde Dehydrogenase 2), an enzyme involved in alcohol metabolism. People with deficient ALDH2 often experience facial flushing after drinking a small dose of alcohol. The present study examined the effect of a small dose of alcohol on driving-related behavior of northeastern Asians (Japanese). Participants were 9 Japanese flushers and 12 Japanese nonflushers. They were evaluated using a driving simulator and self-report of intoxication after ingesting 0.6g/kg or 0.4g/kg of alcohol or a placebo. Facial flushers were more likely to experience subjective feelings of intoxication than were nonflushers. There were no significant differences between facial flushers and nonflushers in blood alcohol concentration and choice reaction time to visual stimuli. Despite having different subjective feelings of intoxication, facial flushers and nonflushers were equally impaired after having ingested equal amounts of alcohol per body weight.