Alcohol and DNA methylation

Alcohol is an environmental toxicant that is associated with several major human diseases because it has harmful effects on many different tissues and organs. Alcohol effects cellular toxicity by several mechanisms, mainly through acetaldehyde, the first metabolite produced during ethanol degradation, and through the formation of reactive oxygen species. Acetaldehyde interferes with DNA synthesis and repair mechanisms and is well recognized as playing a role in cancer of upper and lower gastrointestinal tract. Meanwhile, the hazardous effects of alcohol on the liver are more likely to be mediated by oxidative stress. Several studies have also demonstrated that alcohol impairs one-carbon metabolism leading to an aberrant methyl group transfer, and it is believed that this molecular event may play a role in the develop- ment of cancer and other alcohol-related diseases. In this chapter, we focused on the effects of alcohol on one-carbon metabolism and its influence on DNA methylation, which could be one of the mechanisms involved in the epigenetic effects of alcohol.