Regularly drinking very hot coffee or tea was linked to about three times the risk of one type of esophageal cancer, according to a large study involving nearly 1 million adults in the United Kingdom.
People who preferred their beverages “very hot” had about three times the risk of developing esophageal squamous cell carcinoma compared with those who drank them warm. This form of cancer begins in the cells lining the esophagus.
Those who preferred hot drinks had about 1.7 times the risk compared with people who preferred warm beverages.
The amount consumed also appeared to matter. Drinking six or more hot beverages per day was associated with a 71% higher risk of squamous cell carcinoma.
Researchers observed similar associations for tea and coffee. This suggests that the temperature of the liquid, rather than a particular ingredient in either drink, may explain the association.
The study did not find a link between beverage temperature and esophageal adenocarcinoma. That is another major form of esophageal cancer that develops in glandular cells, typically in the lower part of the esophagus.
Researchers from the University of Oxford analyzed data from 977,282 adults. Participants reported how many cups of tea and coffee they drank each day. They also said whether they preferred the beverages warm, hot or very hot.
About half of the participants came from the Million Women Study and were followed for an average of 14 years. The other half came from the UK Biobank and were followed for 11 years.
Researchers used National Health Service records to identify new cancer diagnoses. Their analysis accounted for other factors, including smoking, alcohol consumption and body weight.
A total of 2,348 participants developed esophageal cancer during the study period. The findings were published in the International Journal of Cancer.
Earlier studies in Asia, Africa, South America and the Middle East had also associated very hot beverages with esophageal cancer. Evidence from Western populations, however, had been more limited.
Repeated exposure to very hot liquids could irritate or injure the cells lining the esophagus. Dr. Aaron Sasson, chief of surgical oncology at Stony Brook Cancer Center in New York, compared the process to repeatedly burning the skin.
“The hotter the liquid, the higher the risk” of thermal injury, Sasson told Fox News Digital.
Researchers estimated that about 14% of squamous cell carcinoma cases could potentially be prevented if people drank their beverages hot rather than very hot. That estimate assumes the association identified in the study reflects a genuine cause-and-effect relationship.
The study itself does not prove that very hot beverages cause cancer. One major limitation was that participants reported their preferred drinking temperature. Researchers did not directly measure how hot their beverages were.
Heat tolerance also differs from person to person. Participants could therefore describe drinks at similar temperatures differently.
Sasson said the findings should be viewed in context. Squamous cell carcinoma of the esophagus is relatively uncommon in the United States. The lifetime risk of developing the disease is less than 1%, he said.
Smoking and heavy alcohol consumption remain better-established risk factors for esophageal cancer. Acid reflux and obesity are also associated with the disease.
The findings do not suggest that people need to stop drinking tea or coffee. Allowing very hot beverages to cool before drinking them could help limit repeated heat-related irritation to the esophagus.