Background: A mechanistic model has been proposed for how alcohol-metabolizing gene variants protect individuals from the development of alcohol use disorders, with heightened sensitivity to alcohol being an early step (endophenotype) in this model. This study was designed to determine whether possession of 2 alcohol-metabolizing genes variations, the aldehyde dehydrogenase ALDH2*2 allele and the alcohol dehydrogenase ADH1B*2 allele, was associated with self-reported sensitivity to alcohol at low doses and at initial use.
Methods: Asian–American college students (N = 784) of Chinese and Korean descent were genotyped at the ALDH2 and ADH1B loci and assessed for lifetime alcohol symptoms following 1 or 2 drinks and level of response to alcohol during the first 5 lifetime drinking episodes.
Results: Participants who had an ALDH2*2 allele were more likely to report experiencing all 6 low-dose symptoms and having heightened initial response to alcohol. An interaction was found between ALDH2*2 and ADH1B*2, with ADH1B*2 being associated with heightened self-reported sensitivity to alcohol only in individuals who also possessed 1 ALDH2*2 allele.
Conclusions: These findings suggest the effects of ADH1B*2 may be felt more strongly in Asians who already have some heightened sensitivity to alcohol from possessing 1 ALDH2*2 allele, but who are not too sensitized to alcohol from possessing 2 ALDH2*2 alleles. These results offer additional insight into the discrepant findings that have been reported in the literature for the role of ADH1B*2 in response to alcohol and the development of alcohol-related problems.