evidence that ADH1C-1 is associated with approximately half the alcohol turnover compared to ADH1C-2. In addition, some Native American groups have been found to carry a third variant of the ADH1C gene (Osier et al., 2002), but that has not been extensively studied. Most importantly, variation in these genes substantially affects the speed at which an individual metabolizes alcohol into acetaldehyde. For example, the speed of oxidation is estimated to be eight times faster for a man who is homozygous for the ADH1B-2 and ADH1C-1 alleles, as compared to a man who is homozygous for the ADH1B-1 and ADH1C-2 alleles (Lee et al., 2006).
