Regular consumption of very hot tea or coffee may increase the risk of developing squamous cell carcinoma of the esophagus by about three times, according to the Experts Club Information and Analytical Center, based on the results of a study by researchers at the University of Oxford published in the International Journal of Cancer.
The researchers analyzed data from 977,282 adult residents of the United Kingdom from two large projects — the Million Women Study and UK Biobank. The average follow-up period was 14.2 years in the first group and 11.1 years in the second. During this time, 2,348 cases of esophageal cancer were identified, including 1,045 cases of squamous cell carcinoma and 1,303 cases of adenocarcinoma.
Participants themselves indicated the temperature at which they preferred to drink tea and coffee — warm, hot or very hot.
Compared with those who preferred warm drinks, people who regularly drank them “very hot” had a 3.17 times higher risk of esophageal squamous cell carcinoma. For the “hot” category, the risk was also elevated, although to a lesser extent. The scientists found no association between beverage temperature and the risk of esophageal adenocarcinoma.
The number of drinks was a separate factor. Among people who consumed six or more cups of hot tea or coffee per day, the risk of esophageal squamous cell carcinoma was approximately 71% higher than among those who drank fewer than six cups, even after taking preferred beverage temperature into account.
At the same time, the study does not mean that coffee or tea themselves are carcinogens. The authors consider repeated thermal damage to the lining of the esophagus to be the most likely mechanism.
The World Health Organization’s International Agency for Research on Cancer classified the consumption of beverages above 65°C as “probably carcinogenic to humans” — Group 2A — back in 2016. This refers specifically to the high temperature, not to the composition of the beverage.
The Oxford researchers note that approximately 13–17% of participants in the two British cohorts preferred their beverages “very hot,” while around 43–44% consumed six or more hot drinks daily.
According to the authors’ calculations, around 14% of cases of esophageal squamous cell carcinoma in the United Kingdom could potentially be prevented if people who prefer very hot drinks reduced the temperature at least to the “hot” category.
At the same time, the results should be interpreted cautiously. The study is observational and shows a statistical association rather than proving a direct cause-and-effect relationship. In addition, beverage temperature was determined on the basis of participants’ self-assessment rather than measured with a thermometer.
The authors also emphasize that the absolute risk of the disease remains relatively low. Among nearly 1 million participants, 1,045 cases of esophageal squamous cell carcinoma were recorded over more than a decade of follow-up. Therefore, a threefold increase in relative risk does not mean that the disease will develop in every third person who regularly drinks very hot tea or coffee.
The most practical conclusion of the study is simple: there is no need to give up coffee or tea, but the drinks should be allowed to cool slightly before consumption.
The main proven risk factors for esophageal squamous cell carcinoma also include smoking and alcohol consumption. The International Agency for Research on Cancer emphasizes that these remain among the main causes of the disease in many countries.
