Drinking scorching coffee or tea triples oesophageal cancer risk, study finds
Study of nearly 1 million people ties scalding drinks to higher cancer odds
Most of us have burned our tongue while drinking coffee that came out of the machine too eagerly, or scalded ourselves waiting impatiently for tea to cool. New research out of Oxford University suggests that habit, drinking beverages while they're still scorching, may carry a real, measurable health cost over time.
Published in the International Journal of Cancer, the study tracked nearly a million middle-aged adults in the UK and found that those who habitually drank their tea or coffee 'very hot' faced roughly triple the risk of oesophageal cancer compared to people who stuck to warmer drinks. It's the largest study of its kind to draw this connection, giving fresh weight to a link scientists had previously only observed in smaller populations notably in South America, where the scalding herbal drink mate is popular.
What counts as too hot?
The researchers set the threshold at 65°C (149°F), anything above that qualifies as 'very hot' in their analysis. For context, tea poured straight after a kettle boils typically sits around 90–95°C, meaning most people are drinking well above the risk threshold unless they pause to let it cool. Milk helps bring the temperature down, but not always enough to fully escape the danger zone.
Volume mattered too: Downing six or more hot drinks daily compounded the risk further, according to the data drawn from 977,282 participants.
The mechanism, researchers explain, is fairly intuitive, repeated exposure to very hot liquid can injure the lining of the oesophagus as it passes through, and that recurring damage may set the stage for cancerous changes over time.
Keeping the risk in perspective
Despite the tripled relative risk, experts are careful to note that oesophageal cancer remains uncommon. Only a few thousand people are diagnosed with the squamous cell type each year in the UK, and the average person's lifetime risk sits around 1%. Even a threefold increase off that small baseline still leaves the absolute risk modest.
Dr. Keren Papier, who led the research, said in a statement, as quoted by BBC, the next step is pinning down more precisely which temperatures carry the most danger: "More research is now needed to identify the exact drink temperatures linked to this increased risk."
A separate, smaller study of 118 young adults taste-testing coffee found people generally didn't perceive a drink as "too hot" until it hit around 70°C — meaning our own sense of discomfort isn't always a reliable warning system. For comparison, one coffee-cup manufacturer notes that takeaway coffee is typically served between 49–60°C for drinkability, though "extra hot" orders can push past 82°C.
The bigger picture
Cancer Research UK, which funded the study, estimates that 10–20% of oesophageal cancer cases might be prevented if people avoided very hot drinks altogether. Still, the charity is quick to point out that temperature is far from the leading risk factor.
"The most important ways to reduce the risk of this cancer type are not smoking and cutting down on alcohol," said Fiona Osgun of Cancer Research UK.
Their practical advice on drink temperature is refreshingly simple: there's no need to obsess over a thermometer. If a drink still feels too hot to sip comfortably, it's too hot to drink — just wait a bit.
Warning signs of oesophageal cancer to watch for include persistent heartburn or indigestion, pain when swallowing, throat or chest discomfort, and unexplained weight loss.
