A study of 977,282 people in the UK has found that it is not what is in your cup that matters for one type of cancer. It is how hot you drink it. People who preferred their tea or coffee "very hot" had about three times the risk of oesophageal squamous cell carcinoma compared with people who drank it warm. The coffee itself was not the problem. The temperature was.
The short version: drink it hot, not scalding. The researchers estimate that if "very hot" drinkers switched to merely "hot", about 14 per cent of this cancer type could be prevented. A flat white is already served in the safe zone. A black coffee straight off the machine is not.
What the study found
Researchers at the University of Oxford, led by nutritional epidemiologist Keren Papier, combined two of the largest health cohorts in the world, the Million Women Study and UK Biobank, and looked at how people said they liked their hot drinks. The results were published in the International Journal of Cancer and re-reported widely this month.
Compared with people who drank tea or coffee warm, those who preferred it "hot" had a 69 per cent higher risk of oesophageal squamous cell carcinoma. Those who preferred it "very hot" had a 3.17 times higher risk. That held after accounting for how many cups people drank. The authors estimate around 14 per cent of cases of this cancer type, roughly 440 a year in the UK, could be prevented if very-hot drinkers let their cup cool slightly.
What it did not find
This is an observational study. It shows an association, not a cause. Temperature was self-reported as a preference, not measured with a thermometer, so "very hot" means whatever each person thought it meant. The study did not test the mechanism, though the authors point to earlier animal research suggesting repeated heat injury to the lining of the oesophagus. It also found no link between the drink itself and this cancer. Coffee drinkers who let it cool were not at higher risk.
The World Health Organization's cancer agency already classifies very hot beverages above 65 degrees as "probably carcinogenic". This study suggests the risk may begin somewhat below that line.
What this means for how you drink coffee
Here is the useful part. Most of the coffee Australians drink is already in the safe zone, and the reason is milk.
A barista steams milk to around 60 to 65 degrees. Hotter than that and the milk loses its sweetness and the texture breaks down, which is why a good cafe will not serve you a scalding flat white even if you ask. By the time the cup reaches your hand and you take the first sip, it is well under 65 and dropping. The same goes for a latte, a cappuccino or a piccolo.
The drinks to watch are the ones without milk. Espresso comes off the machine at roughly 90 degrees and a long black is espresso plus water just off the boil. A pour-over is brewed at 92 to 96 degrees. None of these are a problem if you give them a minute. A black coffee drunk in the first 60 seconds after brewing is the one habit this study would change.
Three practical rules
Let black coffee sit for two minutes
A long black or filter coffee loses heat fast in an open cup. Two minutes takes it from scalding to pleasantly hot, and most people find they taste more of the coffee at the lower temperature anyway. Specialty roasters cup coffee as it cools for exactly that reason: the flavours open up. It is the same reason we recommend brewing black coffee a little cooler than the kettle.
Trust the milk
If your coffee has steamed milk in it and it was made properly, you are already drinking at a temperature the study would call "hot", not "very hot". If a cafe serves you a milk coffee you cannot hold, send it back, for your sake and the coffee's.
Mind the lid
A takeaway lid traps heat. A black coffee under a lid stays very hot for much longer than one in an open cup. Pop the lid off for a minute if you are drinking it straight away.
Two other coffee studies made news this month: one on coffee and repeat blood clots and one on coffee and the liver.
Quick facts
| Study | University of Oxford, International Journal of Cancer, 977,282 participants |
|---|---|
| "Hot" vs warm | 69 per cent higher risk of oesophageal squamous cell carcinoma |
| "Very hot" vs warm | 3.17 times the risk |
| Preventable | About 14 per cent of cases if very-hot drinkers switched to hot |
| Milk coffee serving temperature | About 60 to 65 degrees, inside the safe range |
| Espresso off the machine | About 90 degrees, let it sit |
Common questions
Is drinking very hot coffee bad for you?
A large UK study found people who prefer tea or coffee "very hot" had about three times the risk of one type of oesophageal cancer compared with people who drink it warm. The link is to temperature, not to coffee. Letting a hot drink cool for a minute or two is the practical takeaway.
What temperature should coffee be served at?
Milk coffees are steamed to around 60 to 65 degrees and served immediately. Black coffee comes off the machine or brewer at 90 degrees or more and is best left for a minute or two before drinking, both for safety and because the flavour opens up as it cools.
Does coffee cause oesophageal cancer?
No. The study found the association was with drink temperature, not with coffee or tea themselves. Coffee drinkers who drank it warm were not at higher risk.
Is a flat white too hot?
Not if it is made properly. Milk steamed above about 65 degrees loses its sweetness and texture, so a well-made flat white is served inside the range the study would consider "hot" rather than "very hot".
Taste it as it cools. A good coffee changes as it drops in temperature. Shop beans roasted this week in Hurstville and try a filter brew over five minutes instead of one.
Sources: ScienceAlert, 16 October 2026, reporting Papier et al, International Journal of Cancer. World Health Organization International Agency for Research on Cancer classification of very hot beverages. This article is general information, not medical advice. Talk to your GP about any health concern.
