ALDH2*1/*1 individuals with one ADH1B*2 allele had about one fourth (OR = 0.26) and those with two ADH1B*2 alleles had about one fifth (OR = 0.20) the risk of alcohol dependence compared with individuals with no ADH1B*2 alleles. In ALDH2*1/*2 individuals, those with one ADH1B*2 allele had about one sixth (OR = 0.17) and those with two ADH1B*2 alleles had about one eleventh (OR = 0.09) the risk of alcohol dependence compared with individuals with no ADH1B*2 alleles. In an earlier meta-analysis, Whitfield (2002) found similar protective effects of ADH1B*2 in Asians, but in Caucasians the protection from possessing one ADH1B*2 allele was only about half (OR = 0.47). These results suggest ALDH2 and ADH1B each contribute unique protective effects on alcohol dependence, and the level of protection may be even stronger in conjunction than alone.
