Functional polymorphisms in the genes that code for the enzymes responsible for metabolizing alcohol and acetaldehyde (alcohol dehydrogenase (ADH1B) and aldehyde dehydrogenase (ALDH2)) are consistently associated with protection from AUDs (Li, 2000; Luczak, Glatt, & Wall, 2006). Alcohol consumed by individuals with ALDH2*2 genotypes is metabolized to acetaldehyde, which accumulates in the body due to absent ALDH2 enzyme activity and results in the very unpleasant flushing syndrome (Harada, Agrawal, & Goedde, 1981).
