Pathway from ADI to AUD symptoms influenced by ethnicity and genetics

Studies have shown that an early age of drinking initiation (ADI) increases the chance of developing an alcohol use disorder (AUD). There is limited evidence that ADI differs across ethnic groups. This study examined whether the pathway from ADI to AUD symptoms by early adulthood is influenced by two factors: ethnicity and having the alcohol metabolizing gene variant allele, ALDH2*2. This allele produces an inactive enzyme that leads to higher levels of acetaldehyde during alcohol metabolism, which are associated with unpleasant effects after drinking alcohol and a decreased risk for an AUD.

Researchers examined 604 college students recruited from the University of California, San Diego: 214 of Korean ancestry (107 men, 107 women), 200 of European ancestry (106 men, 94 women), and 190 of Chinese ancestry (99 women, 91 men), each with both biological parents having the same heritage. Participants were genotyped for the ALDH2*2 variant allele and completed a self-report assessment.

The effect of ADI as a risk factor for developing AUD symptoms varied with both ethnicity and ALDH2*2 status. ADI was not associated with AUD symptoms in Korean-Americans with an ALDH2*2 allele or in Chinese-Americans regardless of ALDH2*2 status. This indicates that being Korean (and having the protective ALDH2*2 allele) or Chinese buffered the risk for developing AUD symptoms associated with an early ADI. Although an earlier ADI places some individuals at risk to develop AUD symptoms, the path from ADI to AUD symptoms is complex and can be modified by other factors.