Very Hot Coffee and Cancer Risk: What the New Study Found

A large UK study published September 9 adds new evidence that the temperature of a hot drink—not coffee itself—may matter for the risk of one specific type of esophageal cancer. For coffee drinkers and cafés, the useful takeaway is straightforward: brew for extraction, then let the beverage cool until it is comfortable to drink.

The research does not establish a universal “safe” serving temperature, and it does not show that coffee causes cancer. It examined self-reported preferences for drinking tea and coffee “warm,” “hot,” or “very hot,” then compared those preferences with long-term health records.

What the new study found

The International Journal of Cancer study combined data from 977,282 adults in the UK Biobank and Million Women Study. Average follow-up was 11.1 years in one cohort and 14.2 years in the other, during which researchers recorded 2,348 cases of esophageal cancer.

After adjusting for how many hot drinks people consumed, participants who said they preferred “very hot” drinks had a relative risk of esophageal squamous cell carcinoma (SCC) 3.17 times that of people who preferred warm drinks. The relative risk for those who preferred “hot” drinks was 1.69. Drinking six or more hot beverages per day was also associated with higher SCC risk after accounting for temperature.

The same pattern was not found for esophageal adenocarcinoma, the other major subtype studied. That distinction matters: a headline about “cancer risk” can make the result sound broader than it is.

Relative risk needs absolute context

A threefold relative risk is significant, but it is not the same as saying that three out of every four very-hot-coffee drinkers will develop cancer. Cancer Research UK, which funded the study, notes that lifetime risk of esophageal SCC in the UK is around 1%. Even when a relative risk rises, the individual absolute risk can remain low.

Cancer Research UK also emphasizes that smoking and alcohol are established major risk factors for SCC. Drink temperature is one part of a much larger risk picture.

The study measured preference, not the liquid

This was an observational cohort study. Participants described how hot they liked their drinks, but researchers did not measure the temperature of each beverage. “Very hot” is subjective: one person may use that label for a drink another person would call merely hot.

That limitation means the results show an association, not proof that a particular temperature caused a particular case. The large sample, long follow-up, similar results across two cohorts, and adjustment for smoking, alcohol, and other variables strengthen the evidence, but they do not eliminate every possible source of bias or confounding.

The International Agency for Research on Cancer has classified beverages consumed above 65°C (149°F) as “probably carcinogenic to humans” since 2016. Even that threshold should not be treated like a cliff edge: the new paper describes it as a practical classification point, not a proven biological line between harmless and harmful.

Brewing temperature is not drinking temperature

This distinction is especially important for espresso and specialty coffee. Hot water is used to extract soluble compounds from coffee, but the beverage starts losing heat immediately as it enters the cup. Cup material, beverage mass, room temperature, stirring, added milk, and waiting time all change the temperature that reaches your mouth.

Do not respond to this study by lowering an espresso machine’s PID or kettle set point without considering extraction. Brew-water temperature is a recipe variable; consumption temperature is a service variable. Our guide to variable-temperature kettles explains why a kettle setting and the temperature of the coffee slurry are not identical. The same general principle applies here: the number on the equipment is not necessarily the temperature of the sip.

A small espresso cools faster than a full mug of filter coffee. A milk drink may arrive at a different temperature again, depending on milk volume, cup temperature, and steaming technique. If you steam milk, the milk-temperature guide covers texture and flavor considerations without treating “extra hot” as an automatic quality upgrade.

Practical takeaways at home

• Do not rush the first sip. If a drink feels uncomfortably hot, let it cool.
• Separate extraction from service. Keep the brew recipe that tastes good, then wait before drinking rather than using cooler water by default.
• Stir before judging. Coffee can have hot and cool zones, especially in an insulated or preheated cup.
• Use measurement for your own workflow, not as a universal rule. A clean instant-read thermometer can help you learn how quickly a favorite mug or drink cools, but this study did not determine an exact safe temperature for every person.
• Remember the larger risk picture. Personal medical concerns belong with a qualified healthcare professional, especially when other risk factors are present.

What cafés should—and should not—change

This research is a reason to review service habits, not a reason to make an unverified medical claim at the counter. Cancer Research UK does not recommend that cafés and restaurants adopt a universal lower serving temperature based on this study alone.

Reasonable operational steps include training staff not to equate “hotter” with “better,” following applicable food-service and burn-prevention guidance, keeping lids secure, warning customers when a beverage is unusually hot, and avoiding automatic extra-hot preparation unless it is requested and compatible with product quality.

Cafés should also distinguish public-health evidence from flavor standards. A temperature that supports good milk texture or coffee extraction does not tell you how soon a guest will drink the beverage. Service policy should account for the complete path from machine to cup to customer.

Bottom line

The September 9 study strengthens the case that routinely drinking beverages at very high temperatures may increase the risk of esophageal SCC. It does not implicate coffee as an ingredient, prove causation, or supply a precise café serving limit.

For coffee people, the practical response is modest: keep brewing and drinking temperature conceptually separate, do not treat scalding heat as a mark of quality, and let a very hot cup cool until it is comfortable to drink.

Sources

• Hot Drinks and Oesophageal Cancer: Prospective Analyses in Around 1 Million UK Adults, International Journal of Cancer, published September 9, 2026.
• Cancer Research UK: New UK study links hot drink consumption to one type of oesophageal cancer, September 9, 2026.
• IARC: Cancer of the Oesophagus and Drinking Very Hot Beverages, June 15, 2016.