For generations, the ritual of a hot cup of tea or coffee has been woven into daily life across cultures, yet a study of nearly a million British adults now asks us to reconsider not what we drink, but how we drink it. Researchers drawing on two of the largest health cohorts ever assembled found that a preference for 'very hot' beverages was associated with more than three times the risk of esophageal squamous cell carcinoma — a cancer that claims hundreds of thousands of lives worldwide each year. The finding, which held even among non-smokers and light drinkers, points toward thermal injury
Very Hot Tea and Coffee Linked to Threefold Higher Esophageal Cancer Risk
The study identified 1,045 participants who developed esophageal squamous cell carcinoma during follow-up, highlighting the disease burden that could be reduced through behavioral modification.
Let your tea cool slightly before you drink it.
Mark
So the headline is that very hot tea and coffee triple your cancer risk. But what does "very hot" actually mean in someone's kitchen?
Mimi
That's the tricky part. The study asked nearly a million people to describe their preference as "warm," "hot," or "very hot"—it was subjective. The researchers didn't measure actual temperatures. We know from other work that the IARC classified anything above 65 degrees Celsius as probably carcinogenic, and that Western tea and coffee typically sit around 60 degrees. But in this study, people were just reporting how they liked it.
Luke
Which means we're comparing people's preferences, not precise temperatures. Someone's "very hot" might be another person's "hot." The association is real in the data, but we can't say "switch from 70 degrees to 60 degrees and you'll cut your risk by two-thirds." We just know that people who like it hotter had higher cancer rates.
Mark
And it's only one type of esophageal cancer—squamous cell carcinoma—not the other kind?
Mimi
Exactly. Adenocarcinoma showed no meaningful link to drink temperature. That actually strengthens the thermal injury theory, because squamous cell cancers develop in the upper part of the esophagus, where hot liquid would hit first and hardest. The tissue there seems particularly vulnerable.
Luke
But we should be clear: this is an observational study. They followed nearly a million people for 11 to 14 years and tracked who got cancer. They can show association, not causation. It's possible that people who prefer very hot drinks share some other characteristic that raises cancer risk—though the researchers did control for smoking and alcohol, and the pattern held in never-smokers too.
Mark
What about the frequency finding? Six or more hot drinks a day?
Mimi
That was independent of temperature. Even after accounting for how hot people liked their drinks, consuming six or more daily was linked to a 71 percent higher risk. So it's not just about temperature—it's also about exposure.
Luke
Though again, we're talking about people who drink six or more hot beverages daily. That's a specific group. The study doesn't tell us much about someone who has one very hot cup of tea in the morning.
Mark
The modeling suggests 440 cases a year could be prevented in the UK if this is causal. That's a real number.
Mimi
It is, and it's significant. But it depends on the association being causal, which we don't know for certain. And it assumes people would actually change their behavior—that they'd let their tea cool down. That's a behavioral intervention, not a medical one.
Luke
The honest answer is: we have a strong association in a very large study, but we don't have proof of cause and effect, and we don't have precise guidance on what temperature is safe. What we have is a signal worth taking seriously and a simple thing people could try if they're concerned.
The Pulse
- Nearly a million participants across two major UK cohorts revealed that drinking beverages 'very hot' more than triples the risk of esophageal squamous cell carcinoma, making this the largest and most consequential study of its kind to date.
- The cancer burden is not abstract: 1,045 people in the study developed this specific cancer over the follow-up period, and globally the disease killed nearly 550,000 people in 2020 alone.
- A second independent risk factor emerged — drinking six or more hot beverages daily raised squamous cell carcinoma risk by 71%, suggesting that both temperature and frequency of consumption are separate levers of harm.
- The mechanism appears to be direct thermal injury to the esophageal lining, explaining why only squamous cell carcinoma — arising in the heat-exposed upper esophagus — was affected, while adenocarcinoma showed no temperature link.
- Public health modeling offers a rare note of optimism: if very hot drinkers simply switched to hot beverages, an estimated 440 UK cancer cases per year could be prevented — no drug, no screening program, just a cooler cup.
- Researchers caution that temperature was self-reported rather than measured, and the observational design cannot confirm causation, meaning further study is needed before this becomes formal clinical guidance.
For generations, the ritual of a hot cup of tea or coffee has been woven into daily life across cultures, yet a study of nearly a million British adults now asks us to reconsider not what we drink, but how we drink it. Researchers drawing on two of the largest health cohorts ever assembled found that a preference for 'very hot' beverages was associated with more than three times the risk of esophageal squamous cell carcinoma — a cancer that claims hundreds of thousands of lives worldwide each year. The finding, which held even among non-smokers and light drinkers, points toward thermal injury as a quiet and largely overlooked hazard hiding inside an ordinary comfort. In the long human story of preventable suffering, this study suggests that one small act of patience — letting a cup cool before drinking — may carry consequences far larger than the gesture itself.
A study pooling data from the Million Women Study and UK Biobank — nearly 977,000 participants in total — has produced the clearest evidence yet that the temperature of your morning tea or coffee may carry meaningful health consequences. People who preferred their hot drinks 'very hot' faced more than three times the risk of developing esophageal squamous cell carcinoma compared with those who preferred them 'warm,' over follow-up periods averaging 11 to 14 years. Crucially, this elevated risk applied only to squamous cell carcinoma, not to the adenocarcinoma variant — a distinction that points directly to thermal injury as the likely mechanism, since squamous cells line the upper esophagus where hot liquids make first and most damaging contact.
The study also found that drinking six or more hot beverages daily independently raised squamous cell carcinoma risk by 71 percent, and the two factors — temperature and frequency — appeared to act separately rather than compounding each other. Adding milk to tea or coffee did not explain away the findings, and the associations persisted among non-smokers and light drinkers, ruling out the most obvious confounding culprits. Excluding the first five years of follow-up — to account for the possibility that early undiagnosed cancer might have altered drinking habits — left the results essentially unchanged.
The International Agency for Research on Cancer classified very hot beverages, defined as above 65 degrees Celsius, as 'probably carcinogenic' back in 2016. What this new research adds is scale, a Western population context, and a striking public health calculation: if UK residents who currently drink 'very hot' beverages shifted to simply 'hot,' modeling suggests roughly 440 esophageal cancer cases could be prevented annually — about 14 percent of the country's yearly burden of this cancer type. The researchers acknowledged the study's observational limits and the subjective nature of temperature reporting, stopping short of prescribing an exact cooling time. The recommendation, for now, is as simple as it is accessible: a little patience before the first sip.
Nearly a million British adults have just handed researchers a straightforward warning: the temperature at which you drink your tea or coffee matters more than most people realize. A study pooling data from the Million Women Study and the UK Biobank—977,282 participants in total—found that people who preferred their hot drinks "very hot" faced more than three times the risk of developing esophageal squamous cell carcinoma compared with those who preferred them "warm." Over an average follow-up period of 11 to 14 years, 1,045 participants developed this particular form of esophageal cancer, and 1,303 developed the adenocarcinoma variant. The distinction between these two types proved crucial: temperature preference showed no meaningful connection to adenocarcinoma risk, only to the squamous cell form.
The mechanism appears to be thermal injury. Squamous cell carcinomas arise in the upper two-thirds of the esophagus, where the tissue lining is especially vulnerable to heat damage from liquids consumed at high temperatures. In 2016, the International Agency for Research on Cancer classified drinking very hot beverages—defined as anything above 65 degrees Celsius—as "probably carcinogenic to humans." What this new research adds is scale and specificity: it shows the effect persists in a Western population where tea and coffee are typically consumed at around 60 degrees Celsius, and it quantifies the independent contribution of how often people drink hot beverages.
Beyond temperature preference alone, the study found that consuming six or more hot drinks daily was independently associated with a 71 percent higher squamous cell carcinoma risk compared with drinking fewer than six. The two factors—how hot and how often—appeared to work separately; there was no statistical evidence that they amplified each other. Researchers also tested whether adding milk to tea or coffee might explain the temperature findings by examining a subset of 459,739 women from the Million Women Study. It did not. The association between drink temperature and cancer risk remained essentially unchanged whether women added milk or drank their beverages plain.
These associations held even among people who had never smoked and those who drank little alcohol, ruling out the possibility that smoking or heavy drinking was doing the real work. The researchers acknowledge the study's limitations: participants reported their preferred drinking temperature subjectively rather than having it measured precisely, so the categories "warm," "hot," and "very hot" cannot be translated into exact temperatures. The observational design cannot prove that hot drinks cause the cancer—only that the two are associated. When researchers excluded the first five years of follow-up to account for the possibility that undiagnosed cancer might have changed drinking habits, the findings remained similar.
Yet the public health implications are substantial if the association is indeed causal. Modeling suggests that if people in the UK switched from drinking "very hot" to "hot" beverages, approximately 440 esophageal squamous cell carcinoma cases could be prevented each year—about 14 percent of the annual UK burden of this cancer type. This is not a drug, not a screening program, not a surgical intervention. It is a change in habit: letting your tea or coffee cool slightly before you drink it. The researchers stopped short of specifying an exact cooling time, framing the recommendation as simply reducing the temperature of very hot drinks before consumption.
Esophageal cancer globally kills hundreds of thousands of people each year. The World Health Organization's cancer research agency documented more than 600,000 new cases and nearly 550,000 deaths in 2020 alone. Most of those cases occur in regions where very hot beverages are a cultural norm—parts of South America, the Middle East, and East Asia—but the disease remains a significant burden in Western countries as well. This study, the largest of its kind to date, suggests that a modest behavioral shift could reduce that burden measurably. The mechanism remains incompletely understood, and more research will be needed to clarify how heat damages esophageal tissue and why squamous cell carcinomas are vulnerable while adenocarcinomas are not. For now, the evidence points toward a simple intervention: patience, and a slightly cooler cup.
Notable Quotes
Drink temperature showed no material association with adenocarcinoma risk, only with squamous cell carcinoma, suggesting thermal injury as the mechanism.— Study researchers
Want the full story?
Read the original at News-Medical ↗
Health & Medicine