the high frequency of ADH1BArg48His and ALDH2Glu504Lys variation in some East Asian populations and their pharmacokinetic properties, initial studies explored the association of these alleles with drinking behaviours and alcohol use disorder in Chinese and Japanese individuals51. ADH1BArg48His and ALDH2Glu504Lys showed robust associations with facial flushing, increased skin temperature, increase in pulse rate, and ventilation52. This is the case because after drinking alcohol, carriers of ADH1BHis48 and ALDH2Lys504 have increased acetaldehyde levels and consequently more acetaldehyde-induced toxic effects, which induce a protective effect with respect to alcohol intake53, 54. The same mechanism is observed in populations of African descent for ADH1BArg370Cys (rs2066702; ADH1B*3) which causes an increase in the alcohol oxidation activity. ADH1B and ALDH2 alleles were also identified as risk loci of cancers localized in tissues directly exposed to alcohol ingestion55. With greater power and larger sample sizes, ADH1B variation has now been shown to be the most important genetic influence on alcohol intake and dependence in EUR populations as well.
