Abstract
Consumption of very hot beverages and foods increases the incidence of oral and esophageal cancer but the mechanisms are not known and the critical temperature is not well defined. We realized a study with exfoliated cells from the oral cavity of individuals (n = 73) that live in an area in Iran which has the highest incidence of EC worldwide. Consumption of beverages at very high temperatures is a characteristic feature of this population. We analyzed biomarkers which are (i) indicative for genetic instability (micronuclei that are formed as a consequence of chromosomal damage, nuclear buds which are a consequence of gene amplifications and binucleated cells which reflect mitotic disturbances), (ii) markers that reflect cytotoxic effects (condensed chromatin, karyorrhectic, karyolitic and pyknotic cells), (iii) furthermore, we determined the number of basal cells which is indicative for the regenerative capacity of the buccal mucosa. The impact of the drinking temperature on the frequencies of these parameters was monitored with thermometers. We found no evidence for induction of genetic damage but an increase of the cytotoxic effects with the temperature was evident. This effect was paralleled by an increase of the cell division rate of the mucosa which was observed when the temperature exceeded 60 °C. Our findings indicate that cancer in the upper digestive tract in drinkers of very hot beverages is not caused by damage of the genetic material but by an increase of the cell division rate as a consequence of cytotoxic effects which take place at temperatures over 60 °C. It is known from earlier experiments with rodents that increased cell divisions lead to tumor promotion in the esophagus. Our findings provide a mechanistic explanation and indicate that increased cancer risks can be expected when the drinking temperature of beverages exceeds 60 °C.
Highlights
Consumption of very hot beverages and foods increases the incidence of oral and esophageal cancer but the mechanisms are not known and the critical temperature is not well defined
The rates of KR cells and of cells with condensed chromatin (CC) increased with the drinking temperature; the increase of these anomalies in participants consuming beverages at temperature ≥ 70 °C compared to those drinking them at moderate temperatures was in the range between 2.75- and 2.78-fold, respectively
The results of the present study which was performed with exfoliated cells from the upper digestive tract are relevant for the elucidation of the cellular mechanisms by which consumption of hot beverages and foods causes esophageal cancer (EC) and enable the assessment of the critical temperature leading to adverse effects
Summary
Consumption of very hot beverages and foods increases the incidence of oral and esophageal cancer but the mechanisms are not known and the critical temperature is not well defined. Our findings indicate that cancer in the upper digestive tract in drinkers of very hot beverages is not caused by damage of the genetic material but by an increase of the cell division rate as a consequence of cytotoxic effects which take place at temperatures over 60 °C. Several modes of action may play a role, namely damage of the genetic material[15,16,17,18] as well as acute cell death leading to increased proliferation[19,20,21] This is the first study in which the impact of consumption of hot beverages on cellular alterations (acute cytotoxicity—genetic damage—mitotic activity) was monitored. The results of these investigations made it possible to draw conclusions about which cellular mechanisms are related to malignant transformation of cells of upper digestive tract altered by consumption of hot beverages
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
