A large British study suggests temperature—not tea or coffee itself—may be the critical factor.
OXFORD, UNITED KINGDOM
Regularly drinking tea or coffee at very high temperatures may substantially increase the risk of oesophageal cancer, according to the largest study yet to examine the association in a Western population. Researchers from the University of Oxford followed nearly one million middle-aged adults in the United Kingdom for 14 years.
Participants who reported consuming beverages “very hot” showed almost three times the risk of developing oesophageal squamous cell carcinoma compared with those who preferred them warm. The International Agency for Research on Cancer defines very hot beverages as those consumed at temperatures of 65°C or above.
Quantity also appeared relevant. The association became stronger among people drinking six or more hot beverages per day, suggesting that repeated exposure may matter alongside temperature. Researchers believe recurrent thermal damage could irritate the oesophageal lining and create conditions that make abnormal cellular changes more likely.
The findings demonstrate an association rather than proving that hot drinks directly cause cancer. The study relied partly on participants describing their preferred drinking temperature, and other behavioural or health differences may influence the results. Its large sample and lengthy follow-up nevertheless strengthen earlier evidence connecting sustained exposure to extreme heat with oesophageal damage.
Most tea and coffee is consumed between approximately 50°C and 60°C, below the threshold classified as very hot. Researchers therefore recommend allowing freshly prepared drinks to cool for several minutes, particularly when they feel uncomfortable or painful to swallow. Adding milk may lower the temperature, but does not eliminate the value of waiting before drinking.
Oesophageal cancer remains relatively uncommon. In the United Kingdom, the lifetime probability of receiving a diagnosis is approximately 1%, and the squamous-cell subtype examined in the study represents only part of those cases. A near-tripling of relative risk should therefore not be interpreted as meaning that most consumers of very hot drinks will develop the disease.
Smoking and alcohol consumption remain major preventable risk factors for oesophageal cancer, while obesity is particularly relevant to another principal subtype, adenocarcinoma. Cooling a drink is consequently a sensible precaution, but it should complement—not distract from—reducing tobacco use, moderating alcohol consumption and maintaining a healthy weight.
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