Consuming hot beverages at scalding temperatures significantly increases the risk of oesophageal cancer, according to research from Oxford University involving nearly a million participants. The study, published in the International Journal of Cancer, represents the largest investigation to date establishing this link between thermal exposure and cancer of the food pipe.
People who regularly drank beverages classified as "very hot" faced approximately three times the cancer risk compared with those consuming "warm" tea or coffee, though researchers emphasise that the overall likelihood of developing this cancer remains low. The research defines "very hot" as any drink at 65 degrees Celsius or above, based on analysis of data from 977,282 middle-aged men and women.
How does temperature damage the food pipe?
Steaming liquid damages the cell lining of the oesophagus as it travels down to the stomach. The repeated thermal injury to these cells may trigger inflammation and cellular changes that increase cancer susceptibility over time. This mechanism explains why consistent exposure to very hot drinks poses a greater risk than occasional consumption of hot beverages.
What temperature poses the greatest risk?
Tea prepared immediately after a kettle reaches full boil sits at approximately 100 degrees Celsius (212 degrees Fahrenheit). When poured into a cup, this temperature typically drops to around 90 or 95 degrees Celsius—still well above the 65-degree threshold identified as problematic. Researchers recommend waiting several minutes before drinking to allow beverages to cool to safer temperatures.
A separate investigation of 118 young adults who sampled various black coffees found that most participants perceived drinks as uncomfortably hot only when temperatures exceeded 70 degrees Celsius. Commercial takeaway coffee manufacturers typically recommend serving temperatures between 49 and 60 degrees Celsius for standard hot coffee, though extra-hot requests may result in temperatures exceeding 82 degrees Celsius.
Cancer Research UK notes that determining an exact cooling time is difficult, but suggests waiting until a drink feels comfortable to consume rather than drinking it while still very hot. Adding milk provides only marginal cooling and may not reduce temperatures sufficiently to eliminate risk.
How much hot beverage consumption increases risk?
Consuming six or more hot drinks daily raises oesophageal cancer risk according to the Oxford study data. More recent analysis from a 2025 UK Biobank investigation found that drinking four to six cups daily of hot beverages was associated with a 1.97-fold increased risk, while consuming four or fewer cups daily of very hot beverages showed a 2.52-fold increased risk compared with warm or non-drinkers.
Lead researcher Dr Keren Papier noted that prior research in South America—where many people consume mate, a very hot herbal beverage—had already demonstrated a similar association between thermal exposure and oesophageal cancer.
More research is now needed to identify the exact drink temperatures linked to this increased risk.
What does international evidence show?
The International Agency for Research on Cancer (IARC) classified drinking very hot beverages as "probably carcinogenic to humans" in Group 2A, determining that the cancer risk stems from temperature rather than the beverage type itself. According to IARC analysis of East African data, very hot beverages raised risk 1.92-fold compared with hot beverages. A 2019 study in western Asia reported even higher associations, with very hot drinkers facing 3.7-fold increased risk and hot drinkers facing 1.4-fold increased risk compared with warm drinkers.
The Oxford findings align with decades of international research. IARC first announced in 2016 that very hot beverages probably cause oesophageal cancer based on human and animal evidence. A systematic review concluded that while beverage type and quantity showed limited association with risk, higher drinking temperatures demonstrated stronger evidence of increased oesophageal cancer risk.
What is the actual cancer risk for individuals?
Although very hot drinks substantially increase relative risk, the absolute likelihood of developing oesophageal cancer remains modest. Squamous cell oesophageal cancer is rare, affecting only a few thousand people annually in the UK. Approximately 1% of the population faces a lifetime risk of oesophageal squamous cell carcinoma diagnosis.
The Oxford researchers estimate that eliminating very hot beverage consumption could prevent one or two oesophageal cancers per ten cases. However, other factors pose substantially greater risk. Smoking and alcohol consumption represent more significant oesophageal cancer risk factors than thermal exposure alone.
Fiona Osgun from Cancer Research UK, which funded the study, emphasised priorities:
The most important ways to reduce the risk of this cancer type are not smoking and cutting down on alcohol.
What are the warning signs of oesophageal cancer?
Symptoms of oesophageal cancer include persistent heartburn, indigestion, pain in the throat or chest, and unexplained weight loss. Anyone experiencing these symptoms should seek medical evaluation promptly, as early detection improves treatment outcomes.
Key Facts
- Very hot beverages (65°C or above) increase oesophageal cancer risk approximately threefold compared with warm drinks, according to Oxford University research involving 977,282 participants
- According to 2025 UK Biobank analysis, consuming four or fewer cups daily of very hot beverages was associated with 2.52-fold increased risk versus warm or non-drinkers
- The International Agency for Research on Cancer classifies very hot beverages as probably carcinogenic, with risk linked to temperature rather than beverage type
- Oesophageal squamous cell carcinoma remains rare, affecting only a few thousand people annually in the UK, with approximately 1% lifetime population risk
- Smoking and alcohol consumption represent more significant oesophageal cancer risk factors than thermal beverage exposure
