Very Hot Tea and Coffee Triples Esophageal Cancer Risk

Temperature and Frequency Risks in the UK Study

Researchers examined information covering 977,282 individuals from the UK Biobank and the Million Women Study, under the leadership of Dr Keren Papier, a senior nutritional epidemiologist at the University of Oxford’s population health department. During follow-up periods averaging 14.2 years for the Million Women Study and 11.1 years for the UK Biobank, the team recorded 2,348 new cases of oesophageal cancer. The study identified 1,045 cases of oesophageal squamous cell carcinoma and 1,303 cases of adenocarcinoma.

Participants who reported drinking their beverages at a “very hot” temperature carried a relative risk of 3.17, or a 217% increase, for squamous cell carcinoma compared to those who chose “warm” drinks. Participants who preferred “hot” drinks rather than very hot ones still faced a 69% higher risk than the warm-drink group. Frequency also played an independent role in the data. Drinking six or more hot beverages a day was associated with a 71% increase in squamous cell carcinoma risk compared to consuming fewer than six cups, regardless of the preferred temperature.

However, the temperature and frequency patterns did not apply equally to both major subtypes of oesophageal cancer. Researchers found little to no association between hot drink habits and adenocarcinoma risk. “Consumption of drinks at a ‘very hot’ versus ‘warm’ temperature was associated with a threefold greater SCC risk but not with AC risk, after adjustment for consumption frequency,” according to the study.

Thermal Injury as the Driving Mechanism

Scientists point to repeated thermal injury as the biological driver behind the squamous cell carcinoma findings. Scalding liquids passing through the foodpipe repeatedly over years wear down mucosal integrity. That continuous tissue damage impairs the lining’s ability to repair itself, which can lead cells to divide in ways that promote carcinogenesis. Because squamous cells dominate the upper two-thirds of the oesophagus, that section takes the brunt of the initial contact and shows the highest vulnerability to hot liquids.

The analysis controlled for known confounding factors including smoking, alcohol consumption, exercise, and body measurements. The findings align with previous investigations conducted in Asia, Africa, South America, and the Middle East, where researchers observed that drinking tea or mate at or above 70°C elevated oesophageal cancer rates. The International Agency for Research on Cancer classified hot drinks as “probably carcinogenic to humans” in 2016.

Guidance from Health Authorities on Cooling Beverages

Pinpointing the exact duration required for a hot beverage to cool down proves challenging. Instead, for those feeling concerned, experts advise holding off until the temperature feels comfortable for consumption rather than consuming it while exceptionally hot.

The study team noted that roughly one in seven cases of squamous cell carcinoma in the UK might be avoided if individuals who drink beverages at very hot temperatures allowed them to cool to a standard hot range. The analysis also checked whether specific beverage types altered the outcome. Neither switching between tea and coffee nor adding milk changed the observed cancer pattern.