The population of Trinidad and Tobago is composed mainly of people of East Indian (Indo-Trinidadians) and African (Afro-Trinidadians) ancestry. Differences in alcoholism rates exist between these two ethnic groups, and researchers have investigated whether these differences can be explained in part by variations in the genes encoding the alcohol-metabolizing enzymes alcohol dehydrogenase (ADH) 1B and 1C, and aldehyde dehydrogenase (ALDH) 1 and 2. Studies have demonstrated that a certain variant of the gene encoding ADH1B (ADH1B*3) is associated with a reduced risk of alcoholism in Afro-Trinidadians, as is a variant of the gene encoding ADH1C (i.e., ADH1C*1) in Indo-Trinidadians. An ALDH2 variant shown to have protective effects primarily in East Asians was not found in either Trinidadian ethnic group. However, a variant in the gene encoding cytosolic ALDH1A (i.e. ALDH1A1*1/*2) was found to be associated with an increase in alcohol dependence in Indo-Trinidadians.