Consuming beverages at very high temperatures, above 65 degrees Celsius (149 degrees Fahrenheit), could significantly increase the risk of developing esophageal cancer, according to a major study by scientists at the University of Oxford. People who regularly drank tea and coffee at temperatures above this threshold were found to be three times more likely to develop esophageal squamous cell carcinoma compared to those who consumed drinks at cooler temperatures.
The study, which analyzed data from nearly 980,000 UK adults over more than a decade, also indicated that drinking more than six hot beverages a day, regardless of temperature, was associated with a 71% higher risk of the cancer. Esophageal squamous cell carcinoma is an aggressive form of the disease, with survival rates for affected patients often low due to late-stage diagnosis. In the UK, around a fifth of patients survive for five years after diagnosis.
Researchers estimated that approximately 14% of annual esophageal cancer cases in Britain could potentially be prevented if individuals allowed their hot drinks to cool slightly before consumption. While the absolute risk of developing this cancer remains relatively low in the UK, the findings contribute to a growing body of evidence suggesting a link between habitually drinking very hot beverages and increased cancer risk.
It is believed that the heat from these drinks may damage the cells lining the food pipe, leading to the development of cancer in that region. The study participants reported their preferred drink temperatures as 'warm,' 'hot,' or 'very hot,' and their daily consumption habits. Those who preferred 'very hot' drinks showed a more than threefold increased risk of squamous cell carcinoma compared to those who preferred 'warm' drinks. A slightly elevated risk was also observed for those who preferred 'hot' drinks.
No increased risk was identified for adenocarcinoma, another primary type of esophageal cancer. The researchers noted that the actual temperature of the drinks was not directly measured, but previous research has categorized drinks around 70C as very hot, and the International Agency for Research on Cancer considers beverages above 65C as 'probably carcinogenic.'
In the UK, approximately 9,500 people are diagnosed with esophageal cancer each year, and about 7,900 die from the disease. Early symptoms can sometimes be mistaken for indigestion, contributing to its often late detection. Key risk factors for esophageal cancer also include smoking, obesity, and alcohol consumption. Experts emphasize that not smoking and reducing alcohol intake remain the most critical measures for lowering cancer risk.