compared with 8% in 1986 and 13% in 1992. In a more recent study, approximately 26% of heavy drinking (consuming more than about 400 g of ethanol per week) men in Tokyo were ALDH2 Lys487 heterozygotes [35]. In other East Asian countries, estimates of the percentage of alcoholics who are low-activity ALDH2 heterozygotes range from 17% in Taiwan in 1999 [26] to 4% in Korea in 2007 [27]. Taken together, these observations indicate that the inhibitory effect of heterozygous ALDH2-deficiency on alcohol consumption can be strongly influenced by local social and cultural factors which may change over time.
