New Plausible Mechanism for Gastric and Colorectal Carcinogenesis: Free Radical-Mediated Acetaldehyde Generation in a Heme/Myoglobin-Linoleate-Ethanol Mixture

Free radical-mediated acetaldehyde formation by model reactions of dietary components: effects of meat, wine, cooking oil and coffee

Background

Alcohol consumption and the ingestion of red meat and oxidized cooking oil are risk factors of gastric and colorectal cancers. We reported that acetaldehyde (AcAld) is generated from Heme/Mb/Meat-Linoleate-EtOH model reaction mixtures, and thus could be a new plausible mechanism for the carcinogenesis (Kasai and Kawai, ACS Omega, 2021).

Results

In this study, we investigated the effects of wine and coffee, in addition to meat components, on this reaction. Depending on the conditions, such as pH, reaction time and choice of free hemin, myoglobin (Mb), as well as meat extracts (raw meat, baked meat, salami), wine and coffee enhanced AcAld formation. Polyphenols in red wine and coffee may stimulate AcAld formation by acting as pro-oxidants in the presence of Heme/Mb/Meat. In a model reaction of Mb + EtOH + H₂O₂, we observed time-dependent AcAld formation. In support of these in vitro data, after the consumption of a red meat-rich diet with red wine, the fecal AcAld level significantly increased as compared to the levels associated with a diet of fish + wine, or red meat without alcohol.

Conclusions

These results suggested that AcAld generation from dietary components may be an important mechanism of gastrointestinal tract carcinogenesis.