Drinking very hot tea or coffee is linked to an almost threefold increase in the risk of squamous cell carcinoma of the esophagus, according to a study by researchers at the University of Oxford published in the International Journal of Cancer.
The scientists analyzed data from 977,000 adults who reported how much tea and coffee they drank and whether they preferred their beverages warm, hot or very hot. Participants were followed for more than ten years, during which time 2,348 of them developed esophageal cancer.
Threefold increase in risk
People who preferred very hot drinks had roughly three times the risk of developing squamous cell esophageal cancer compared with those who preferred warm drinks, the researchers found. The risk was also higher among people who drank six or more cups of tea or coffee a day.
The results were similar for both tea and coffee, which the researchers said points to the temperature of the drink, rather than the drink itself, as the key factor behind the increased risk.
No link found for other tumor type
For esophageal adenocarcinoma, another common type of tumor affecting the esophagus, the researchers found no clear connection to drink temperature.
Squamous cell carcinoma and adenocarcinoma are the two main forms of esophageal cancer. Squamous cell carcinoma develops in the flat cells lining the esophagus, while adenocarcinoma arises in the glandular cells, often linked to acid reflux. The esophagus is the tube connecting the throat to the stomach, and cancers affecting it are among the more difficult malignancies to treat.
Simple way to cut the risk
The study's authors suggested that the risk could be reduced with a simple change in habit: letting tea and coffee cool slightly before drinking them.
Oxford University, where the research was conducted, is one of the world's leading centers for population health research and has previously produced large-scale studies on diet and disease risk drawing on data from hundreds of thousands of participants.
The findings come after other researchers previously found that regular tea drinking slows the development of liver fibrosis, a scarring of the liver tied to chronic disease.
