The habit of consuming food and drinks hotter than 65 degrees Celsius causes repeated thermal burns of the esophageal mucosa, promoting cell proliferation and increasing the risk of developing cancer.
The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) classifies very hot drinks (over 65 degrees Celsius) in group 2A – a group of factors “possibly carcinogenic to humans”. Evaluation is based on comprehensive reports from medical journals The Lancet Oncologythrough analyzing epidemiological data in areas with traditional tea and beverage drinking practices at high temperatures. Experts identify the clearest link between this habit and the risk of squamous carcinoma of the esophagus, instead of the entire digestive system.
In daily activities, freshly brewed tea usually reaches 80 to 90 degrees Celsius, while liquid dishes such as vermicelli, pho, and noodles just scooped into bowls maintain a temperature of 70 to 80 degrees Celsius. Both of these temperatures exceed the safety threshold of the digestive tract mucosa.
High temperatures do not directly change genetic structure but cause physical damage. When exposed to very hot food, the delicate layer of epithelial cells lining the inside of the esophagus becomes thermally burned and peels off. The body activates its self-repair mechanism by promoting rapid cell division to regenerate the damaged area.
Continuous inflammation and regeneration over many years increases the probability of errors when copying DNA, creating conditions for malignant mutations to form. At the same time, the damaged protective barrier of the esophagus also makes the mucosa more susceptible to absorbing other carcinogenic agents, especially in people with the habit of smoking or drinking alcohol.
Health experts advise people not to rush to eat food as soon as it leaves the kitchen. The simplest action to protect the esophagus is to cool food and drinks to a moderately warm state (below 65 degrees Celsius) before enjoying.