Alcohol dehydrogenase (ADH) is one of the major enzymes involved in alcohol metabolism. The genes for ADH are polymorphic at two loci, ADH1B and ADH1C. While the three alleles at the ADH1B locus have previously been linked with protection from alcohol dependence, a new study is the first to examine the relationship between the ADH1B*3 allele and alcohol-related disorders among Afro-Trinidadians. Findings indicate that while the ADH1B*3 allele appears to protect against alcoholism, it can also increase the risk for liver disease among those individuals who drink heavily.
Results are published in the February issue of Alcoholism: Clinical & Experimental Research.
"Alcohol is primarily metabolized or broken down in the liver by two enzymes," explained Cindy L. Ehlers, associate professor of molecular and integrative neuroscience at The Scripps Research Institute. "The first is ADH, which converts alcohol to acetaldehyde. Acetaldehyde is a toxic compound that can be damaging to the liver and other body organ systems. The second enzyme is aldehyde dehydrogenase (ALDH), which breaks down acetaldehyde to acetate, a relatively nontoxic compound."
Ehlers said that most people do not realize that people of different racial origins metabolize alcohol differently and that this influences their risk for alcoholism. "Approximately 40 percent of Asians have a mutation in ALDH that may cause them to have an aversive reaction when they drink so they are much less likely to develop alcohol dependence