According to a study published in the December edition of the journal Drug and Alcohol Dependence, almost 6% of all cancers worldwide are attributable to alcohol use and approximately half of them occur in tissues highly exposed to ethanol, such as the oral cavity, pharynx, upper larynx and esophagus. However, since ethanol is not mutagenic and the mutagenic metabolite of ethanol (acetaldehyde) is mainly produced in the liver, it is unclear why alcohol consumption preferentially exerts a local carcinogenic effect.
Recent findings indicate that the risk of cancer in a tissue is strongly correlated with the number of stem cell divisions accumulated by the tissue; the accumulation of stem cell divisions leads to the accumulation of cancer-promoting errors such as mutations occurring during DNA replication. Since cell death activates the division of stem cells, the authors suggest that the possible cytotoxicity of ethanol on the cells lining the tissues in direct contact with alcoholic beverages could explain the local carcinogenic effect of alcohol. In the study the authors report that short-term exposures (2-3 s) to ethanol concentrations between 10% and 15% start to cause a marked cytotoxic effect on human epithelial keratinocytes in a concentrationdependent manner.
The authors therefore propose that choosing alcoholic beverages containing non-cytotoxic concentrations of ethanol, or diluting ethanol to non-cytotoxic concentrations, may be a simple and effective way to reduce the risk of cancers of the oral cavity, pharynx, larynx and esophagus in alcohol users. This preventive strategy may also reduce the known synergistic effect of alcohol drinking and tobacco smoking on the risk of these cancers.
Source: Avoiding the ingestion of cytotoxic concentrations of ethanol may reduce the risk of cancer associated with alcohol consumption. Guillén-Mancina E, Calderón-Montaño JM, López-Lázaro M. Drug Alcohol Depend. 2017 Dec 27;183:201-204.