Role of alcohol consumption and antioxidants on global methylation of DNA and cancer

Alcoholism is a chronic relapsing disease associated with psychological, social and physical dysfunction. Alcohol is not only an addictive substance, it also alters action and function of multiple systems and organs. Currently, several studies show that the environment can modulate gene expression of DNA by epigenetic mechanisms, thereby suggesting that alcohol consumption is a factor that can alter epigenetic patterns and therefore, the levels of gene expression. DNA methylation is an epigenetic process, that is a part of gene expression regulation preventing binding of transcription factors and encouraging the closed structure of chromatin. In this sense, changes in DNA methylation are recognized as one of the most common forms of molecular alteration in alcohol dependence and human neoplastic processes. Alcohol can be an important factor in activating the cancer by increasing the expression of certain oncogenes or repressing the ability of cells to repair DNA, which increases the likelihood of oncogenic mutations. However, the exact mechanisms of the pathogenesis of cancer linked to alcohol consumption remain unclear. Therefore, the objective of this review was to describe the mechanisms of DNA methylation and its relation to alcohol consumption and cancer.