Gene-by-Environment Interactions on Alcohol Use Among Asian American College Freshmen.

OBJECTIVE: Among northeast Asians, the variant aldehyde dehydrogenase allele, ALDH2*2 (rs671, A/G, minor/major), has been inversely associated with alcohol dependence. The strength of the associations between ALDH2*2 and drinking behaviors depends on the developmental stage, the phenotype studied, and other moderating variables. This study examined ALDH2 gene status as a moderator of the associations between parental drinking, peer drinking, and acculturation with alcohol use among 222 Chinese American and Korean American college freshmen.

METHOD: Negative binomial regressions were used to test the main and interactive effects of ALDH2 with contextual factors on alcohol frequency (drinking days) and quantity (drinks per drinking day) in the past 3 months.

RESULTS: ALDH2*2 was associated with more subjective flushing symptoms and longer length of flushing but was unrelated to both alcohol frequency and quantity. Peer drinking was positively associated with both alcohol frequency and quantity, but neither was moderated by ALDH2. We observed a nonsignificant trend for the interaction between parental drinking and ALDH2 on alcohol frequency, where parental drinking was positively associated with alcohol frequency only among participants with ALDH2*2. We found a significant interaction between acculturation and ALDH2 on alcohol frequency, where acculturation was positively associated with alcohol frequency only among those with ALDH2*2. Exploratory analyses stratified by Asian ethnic subgroup indicated that this interaction was driven primarily by the Korean subsample.

CONCLUSIONS: Parental drinking and acculturation may facilitate more frequent drinking among those who have more intense reactions to alcohol (i.e., those with ALDH2*2) during the transition from high school to college.