Very hot drinks and oesophageal cancer: what the new UK study tells us
A UK study links very hot tea and coffee to a three‑fold rise in oesophageal squamous cell carcinoma. Find out why and how to lower your risk this week.
A startling link between scalding drinks and cancer
A new analysis of nearly one million UK adults finds that drinking tea or coffee at a "very hot" temperature triples the risk of oesophageal squamous cell carcinoma (SCC). The finding matters because hot drinks are a daily habit for many, and a change in drinking temperature could cut a sizeable proportion of a serious cancer.
Why oesophageal cancer matters
The oesophagus, the food pipe that runs from the mouth to the stomach, can develop two main types of cancer: squamous cell carcinoma (SCC) and adenocarcinoma (AC). SCC arises from the thin, flat cells lining the upper and middle oesophagus, while AC originates in the lower part, often after Barrett's oesophagus. In the UK, SCC accounts for about 10 % of oesophageal cancers, but it carries a five‑year survival of roughly 20 % because it is usually diagnosed late. Known risk factors include smoking, heavy alcohol use, and, increasingly recognised, chronic thermal injury from very hot drinks.
The new UK study – scale and key numbers
According to The Guardian reporting on a study published in the International Journal of Cancer, researchers followed 979,984 participants for 14 years. Participants reported how they preferred their drinks – "very hot", "hot", "warm" or "do not drink hot drinks" – and how many cups they consumed each day.
Temperature effect: Compared with "warm" drinks, "very hot" drinks were associated with a three‑fold higher risk of SCC (hazard ratio ≈ 3.0). No increased risk was seen for AC.
Frequency effect: After adjusting for temperature, drinking six or more hot drinks a day raised SCC risk by 71 % compared with fewer than six.
Population impact: The authors estimate that one in seven UK SCC cases could be avoided if people who drink "very hot" beverages switched to a "hot" or "warm" temperature.
These figures come from self‑reported temperature categories rather than measured degrees Celsius, but the size of the cohort makes the associations robust enough to inform public‑health guidance.
How heat damages the oesophagus
The oesophageal lining is only a few cell layers thick and lacks the protective keratinised coating found in the skin. When a liquid exceeds roughly 70 °C (158 °F), it can cause microscopic burns that trigger inflammation. Repeated injury leads to DNA damage and a cycle of cell turnover, creating an environment where mutations can accumulate and malignant clones can emerge. This thermal injury pathway is distinct from the chemical carcinogenesis caused by alcohol or tobacco, but the end result – uncontrolled cell growth – is the same.
Risk compared across temperature and frequency
| Drink temperature (self‑reported) | Relative risk of SCC vs "warm" | Typical serving size* | Frequency needed for 71 % risk rise |
|---|---|---|---|
| Very hot | ≈ 3.0 × higher | ~200 ml (standard mug) | ≥ 6 cups/day |
| Hot | Not quantified in the paper (likely intermediate) | ~200 ml | — |
| Warm | Baseline (1.0) | ~200 ml | — |
| No hot drinks | Baseline (1.0) | 0 ml | — |
*Serving size is the usual UK mug volume; the study did not record exact millilitres.
The table shows that temperature is the dominant factor – a three‑fold jump in risk – while high frequency adds a further 71 % increase on top of temperature effects. In practice this means that someone who drinks six very hot mugs a day may face a risk roughly four times the baseline.
What you can change this week
- Test the temperature: Fill a mug and wait until the steam has noticeably lessened – roughly 5 minutes for a freshly boiled cup. The liquid will usually be around 60–65 °C, a temperature most people find comfortable.
- Use a thermometer: If you enjoy tea at a precise temperature, an inexpensive kitchen thermometer can confirm you stay below 70 °C.
- Sip, don’t gulp: Smaller mouthfuls reduce the time the hot liquid contacts the oesophageal lining.
- Track your intake: Aim for fewer than six hot drinks a day; consider replacing one with a cold beverage or a warm (not hot) alternative.
- Mind other risk factors: If you smoke or drink heavily, cutting back on hot drinks adds a modest but meaningful protective layer.
Implementing any one of these steps is realistic within a week and aligns with NHS advice to adopt gradual, sustainable habit changes.
Caveats and unanswered questions
The study’s reliance on self‑reported temperature introduces subjectivity. People who prefer very hot drinks may have altered thermosensation – a heightened tolerance that could itself be linked to biological pathways predisposing them to SCC. Professor Muy‑Teck Teh notes that this possibility blurs the line between cause and correlation. Moreover, the research does not provide exact temperature thresholds; the "very hot" category likely spans a range from 70 °C up to the boiling point, and the risk may increase progressively rather than abruptly.
Other gaps include:
- Measurement of actual temperature: Future work with calibrated thermometers could refine the dose‑response curve.
- Interaction with other risk factors: The study adjusted for smoking and alcohol, but did not explore whether hot‑drink temperature synergises with these exposures.
- Effect on adenocarcinoma: No association was found, but the biological reasons for the divergence remain speculative.
Until these questions are answered, the safest public‑health message is to avoid the hottest possible drinks and to limit the number of daily servings.
What to watch next
The researchers suggest that lowering the average consumption temperature could prevent even more SCC cases. Watch for NHS England or Public Health England guidance that may incorporate temperature advice into broader dietary recommendations. Additionally, any follow‑up studies that use objective temperature measurements will help clarify how much risk reduction is achievable by modest cooling.
