BACKGROUND:

About half of certain Asians have a deficiency of the low-Km aldehyde dehydrogenase (ALDH2) isoenzyme. This deficiency results from inheritance of a mutant ALDH2*2 allele.

OBJECTIVE:

To determine whether Asian Americans with ALDH2*2 alleles differ from Asian Americans without this mutation in terms of blood levels of alcohol and acetaldehyde after ingestion of a moderate amount of alcohol.

DESIGN:

Double-blind, crossover study.

SETTING:

Private research institute.

PARTICIPANTS:

35 healthy Asian-American men. Three men who became ill after alcohol ingestion and one who had outlying data were excluded.

INTERVENTION:

Alcoholic beverage, containing 0.56 g of alcohol per kg of body weight, or placebo beverage, containing 3 mL of alcohol, given orally on separate occasions.

MEASUREMENTS:

Blood levels of alcohol and acetaldehyde measured before and several times after ingestion of the alcoholic or placebo beverage.

RESULTS:

Participants with ALDH2*2 alleles had significantly higher blood acetaldehyde levels after ingesting alcoholic and placebo beverages than did participants with ALDH2*1 alleles, despite similar blood alcohol concentrations.

CONCLUSIONS:

Blood acetaldehyde levels rather than blood alcohol concentration may mediate enhanced alcohol sensitivity among Asians with ALDH2*2 alleles.