The combined studies of AD and alcohol abuse showed that there was strong evidence of association, in particular, in the Asian populations, using both the allelic (350Val vs. 350Ile) and genotypic analyses (Table 1). The strict random effects model was applied when evidence of heterogeneity was found throughout this meta-analysis. The P value was 1×10−8 with OR of 1.51 (1.31, 1.73). Strong evidence of association was also found under the dominant (ValVal + ValIle vs. IleIle: OR = 1.65 (1.38, 1.96)) and recessive models (Table 1). Furthermore, the Asian populations showed a highly significant association, with an allelic P value of 4×10−33 (OR = 2.14 (1.89, 2.43)) with no evidence of heterogeneity between studies (P > 0.05). It was interesting that the dominant and recessive models produced stronger effect sizes (ORs = 2.2 (1.92, 2.53) and 3.83 (2.26, 6.49), respectively) although the underlying biological mechanism was not yet established. Strong evidence of association was also detected in the combined Asian and European populations (P = 3×10−8 and 2×10−7 for the allelic analysis and dominant model, respectively). The Mexican samples revealed
