ALDH2*2 and peer drinking in East Asian college students.

BACKGROUND

The ALDH2*2 allele (A-allele) at rs671 is more commonly carried by Asians and is associated with alcohol-related flushing, a strong adverse reaction to alcohol that is protective against drinking. Social factors, such as having friends who binge drink, also contribute to drinking in Asian youth.

OBJECTIVES

This study examined the interplay between ALDH22, peer drinking, and alcohol consumption in college students. We hypothesized that the relationship between ALDH22 and standard grams of ethanol per month would vary based on the level of peer drinking.

METHODS

Subjects (N = 318, 63.25% female) were East Asian college students in the United States who reported drinking alcohol. Data were from the freshman year of a university survey that included a saliva DNA sample. ALDH22 status was coded ALDH22(+) (A/G and A/A genotypes) and ALDH2*2(-) (G/G genotype). Peer drinking was students' perception of how many of their friends "got drunk".

RESULTS

Main effects of ALDH22(-) and having more friends who got drunk were associated with greater alcohol consumption. The ALDH22 × peer drunkenness interaction showed a stronger positive association with alcohol consumption for ALDH22(-) versus ALDH22(+) at increasing levels of peer drunkenness. Follow-up comparisons within each peer drunkenness level identified significantly higher alcohol consumption for ALDH22(-) compared to ALDH22(+) at the all friends got drunk level.

CONCLUSION

There was evidence of a stronger effect for ALDH22(-) compared to ALDH22(+) with greater alcohol use when students were more exposed to peer drinking. Findings contribute to a growing literature on the interrelationships between genetic influences and more permissive environments for alcohol consumption.