- Drinking very hot beverages may triple the risk of oesophageal cancer compared with drinking them warm, according to a major Oxford study.
- Researchers analysed data from 977,282 middle-aged men and women, making it the largest study of its kind so far.
- Drinks at 65°C or above were classified as “very hot” and linked to higher risk.
- Drinking six or more hot drinks a day was also associated with increased risk.
- Experts stress that smoking, alcohol, and excess weight remain much bigger established risk factors than hot drinks.
For millions of Britons, the ritual is almost automatic: kettle on, mug ready, tea bag in, boiling water poured, and then, perhaps, an impatient first sip.
But researchers at the University of Oxford say there could be a reason to let that brew cool before drinking it.
A new study involving almost one million people suggests that regularly drinking tea or coffee at very high temperatures may increase the risk of oesophageal cancer, also known as cancer of the gullet or food pipe.
People who reported drinking their beverages “very hot” had around three times the risk of oesophageal cancer compared with those drinking them warm.
That sounds alarming. But there is an important catch: the overall risk of developing this cancer remains relatively low.
How hot is “too hot”?
The Oxford researchers define a “very hot” drink as one heated to 65°C or above.
That is considerably cooler than freshly boiled kettle water.
Water boils at 100°C (212°F). When it is poured straight into a cup, the temperature of a tea or coffee can still be around 90–95°C, depending on the cup, drink and surrounding conditions.
In other words, that first sip taken almost immediately after the kettle clicks off could be dramatically hotter than the temperature considered comfortable or potentially safer to drink.
Adding milk may bring the temperature down slightly, but researchers caution that a milky tea or coffee can still be far too hot.
One study involving 118 young adults found that most participants considered black coffee too hot to drink only at around 70°C or above.
For takeaway coffee, one cup manufacturer recommends a drinking temperature of roughly 49–60°C. Coffee served “extra hot” can exceed 82°C.
What actually happens inside the gullet?
The theory is relatively straightforward.
Repeated exposure to scalding-hot liquid can cause thermal injury to the cells lining the oesophagus, the tube carrying food and drink from the mouth to the stomach.
Repeated irritation and damage may contribute to changes in those cells over time, potentially increasing the likelihood of cancerous changes.
The idea is not entirely new.
Previous research from South America, where people commonly drink extremely hot mate, has found a similar association between very hot beverages and oesophageal cancer.
What the new Oxford research adds is a much larger UK dataset, strengthening the evidence that temperature itself may matter, rather than simply what is in the cup.
Dr Keren Papier, the study's lead researcher, says more research is still needed to determine the exact temperatures at which the risk begins to rise.
Britain already has a serious oesophageal cancer problem
The findings are particularly interesting in the UK because Britain already has an unusually high burden of oesophageal cancer.
Around 9,200 people are diagnosed with oesophageal cancer in the UK each year, and the UK has one of the highest rates in Europe, about 6.4 cases per 100,000 people annually, compared with a European average of roughly 3.3 per 100,000.
That makes the hot-drinks finding more than a curiosity in a country where tea and coffee are consumed relentlessly.
The UK's high rates of oesophageal cancer are generally linked to established risk factors including smoking, alcohol consumption and obesity.
So the message is not that Britain's tea habit suddenly ranks alongside smoking.
It doesn't.
Rather, very hot drinks could represent another, potentially avoidable piece of the puzzle.
The bigger UK picture: tea isn't the main villain
Cancer Research UK stresses that the most important ways of reducing the risk of oesophageal cancer are not smoking and cutting down on alcohol.
Smoking alone accounts for around 35 per cent of oesophageal cancer cases in the UK, while more than 25 per cent are attributed to being overweight or obese. Alcohol is another significant contributor.
The hot-drink effect therefore needs to be put into perspective.
Even if drinking scalding tea increases an individual's relative risk, the absolute likelihood of developing oesophageal cancer is still comparatively small.
Around 1 per cent of people in the UK are estimated to develop squamous cell oesophageal cancer during their lifetime.
That distinction matters: a threefold increase in a small baseline risk does not mean that one in three people drinking very hot tea will develop cancer.
But six cups a day changes the conversation
Temperature isn't the only factor identified by the researchers.
The study also found that people consuming six or more hot drinks a day had a higher risk.
That is significant for Britain because tea and coffee are not occasional indulgences for many people, they are woven into the working day, commuting, socialising and even the humble British biscuit break.
The potential issue is therefore not simply what people drink, but how hot and how frequently they drink it.
A single warm cup is a very different proposition from repeatedly swallowing near-scalding liquid throughout the day.
This isn't the first warning from UK Biobank data
The Oxford findings also build on earlier research using data from the UK Biobank.
A related study published in February 2025, involving 454,796 adults, reported that consuming four to six cups of hot beverages a day was associated with almost twice the risk of squamous cell oesophageal cancer.
For people drinking beverages described as very hot, the risk was around 2.5 times higher, with risk increasing further as daily consumption rose.
The new research involves more than twice as many participants, 977,282 people, and appears to represent a larger examination of essentially the same UK Biobank population.
Together, the findings make the temperature question increasingly difficult to dismiss, although observational research cannot by itself prove that hot drinks directly cause cancer.
The cancer is rare, but can be devastating
Oesophageal cancer is not among Britain's most common cancers, but its consequences can be severe.
Symptoms can include persistent heartburn or indigestion, difficulty swallowing, pain in the throat or chest and unexplained weight loss.
Survival remains poor compared with many other cancers. Fewer than 20% of people diagnosed with oesophageal cancer in the UK survive beyond five years.
That grim statistic helps explain why prevention is so important.
Yet prevention does not mean abandoning Britain's beloved brew.
So, should you stop drinking tea?
Probably not.
The practical takeaway is much simpler: let it cool.
Cancer Research UK says there is no exact number of minutes that everyone should wait because drinks cool at different rates depending on their volume, container, and surroundings.
Its advice is essentially common sense: wait until the drink is comfortable to drink rather than consuming it while it is still very hot.
That may mean giving the kettle a few minutes to do its work, rather than immediately putting the mug to your lips.
And if you're looking to reduce your overall oesophageal cancer risk, the bigger wins remain clear: don't smoke, moderate alcohol consumption, and maintain a healthy weight.
The curious case of Britain's boiling brew
The striking part of this research is not that tea or coffee themselves have suddenly become cancer-causing drinks.
It is the possibility that temperature, something most people never think about, could matter.
For generations, Britain's kettle culture has rewarded speed: boiling water, quick pour, quick sip.
Perhaps the new lesson is less dramatic.
Keep the tea. Just lose the scald.
After all, your cuppa doesn't need to be cold.
It just doesn't need to be boiling hot.
