Do very hot drinks raise your risk of esophageal cancer?

Yes, for one type. In 977,282 UK adults, people who liked their tea and coffee “very hot” had about 3 times the risk of esophageal squamous cell carcinoma compared with people who drank them warm. Drink temperature had no clear link to adenocarcinoma, the other main type of esophageal cancer.

The esophagus is the tube that carries food and drink from your throat to your stomach. Earlier studies in Asia, Africa, South America and the Middle East found that tea or mate, a South American herbal drink, raised esophageal cancer risk when people drank it at very high temperatures, around 70°C (158°F). Much less was known about the drink temperatures that are normal in Western countries. Researchers at the University of Oxford set out to answer that question using two large UK groups, the Million Women Study and UK Biobank, and they looked at the two main types of esophageal cancer separately.

What the data show about hot drinks and esophageal cancer

During follow-up, 2,348 people developed esophageal cancer. Of those, 1,045 had squamous cell carcinoma and 1,303 had adenocarcinoma. That works out to about 1 in 935 participants developing squamous cell carcinoma over 11 to 14 years, so this is an uncommon cancer to begin with.

People who preferred their drinks “very hot” had about 3 times the risk of squamous cell carcinoma compared with those who preferred them “warm” (hazard ratio 3.17). The true increase is very likely between about 2.5 and 4 times. This held after the researchers accounted for how many hot drinks people had each day, and they saw a clear trend in risk across the temperature groups. Adenocarcinoma was different. Very hot drinks made no clear difference to it (hazard ratio 0.92), with a range running from 24% lower to 12% higher risk.

How many hot drinks a day matters too

The number of cups carried its own risk. After the researchers accounted for drink temperature, people who had 6 or more hot drinks a day had about 71% higher risk of squamous cell carcinoma than people who had fewer than 6 (hazard ratio 1.71). That increase is very likely between 51% and 94%. For adenocarcinoma, the link was much smaller, about 19% higher risk (hazard ratio 1.19, very likely between 6% and 33%), which the authors describe as little association.

The researchers estimate that about 14% of squamous cell esophageal cancers in UK adults could be avoided if people who drink very hot drinks switched to the temperature the study called “hot.” They add that cooling drinks further, to well below the average for this group, may prevent an even larger share.

Dr. Kumar’s Take

This is one of the easiest cancer risk factors to change. Nobody has to give up tea or coffee to act on it. The fix is waiting a few minutes before the first sip.

The result also fits what the earlier studies found in countries where people drink tea or mate scalding hot, and it carries that finding over to ordinary British drinking habits. The split between the two cancer types makes the result more believable to me. If a preference for very hot drinks were only a stand-in for some other unhealthy habit, you might expect both cancer types to rise together. They did not. Temperature tracked squamous cell carcinoma and left adenocarcinoma alone.

How strong is the evidence?

The size is a real strength. The study followed 977,282 people for an average of 14.2 years in the Million Women Study and 11.1 years in UK Biobank. Drinking habits were recorded before anyone was diagnosed, so memories of past habits could not be colored by a cancer diagnosis.

This is still an observational study, so it shows a link rather than proof that heat causes the cancer. Temperature was each person’s own description of how they liked their drinks, not a thermometer reading, and one person’s “hot” may be another person’s “very hot.” The participants were middle-aged UK adults.

Practical takeaways

Let a fresh cup of tea or coffee sit for a few minutes, or add a splash of cold milk or water, so you drink it warm rather than very hot.
If you have 6 or more hot drinks a day, cutting back is worth considering, since that level carried about 71% higher risk of squamous cell carcinoma in this study even after accounting for temperature.
Keep enjoying tea and coffee if you like them, because the risks in this study were tied to very hot temperatures and high daily counts, not to having a cup at all.

FAQs

How hot is too hot for tea or coffee?

The studies that first raised concern, in Asia, Africa, South America and the Middle East, involved drinks around 70°C (158°F). This UK study found risk rising at temperatures people in a Western country normally choose, and the researchers suggested keeping drinks well below the average temperature people in this study preferred. A simple home test is to wait until you can take a full sip without any stinging or burning. A splash of cold milk or water brings the temperature down right away.

How common is esophageal cancer?

In this study, 2,348 of 977,282 people developed esophageal cancer during 11 to 14 years of follow-up, or about 1 in 416. More than half of those cases were adenocarcinoma, the type that drink temperature did not affect. Squamous cell carcinoma, the type linked to very hot drinks, affected about 1 in 935 participants. A tripling of risk is a big relative jump, but it applies to a cancer that most people will never get. That is why the authors frame temperature as a prevention target across the whole population, where small changes add up to fewer cases.

Do I need to stop drinking tea or coffee?

No. The comparisons in this study were very hot versus warm drinks, and 6 or more a day versus fewer than 6. Both of those changes are within reach without giving up your morning cup. The researchers describe temperature and frequency as useful targets for preventing squamous cell carcinoma, which points toward cooler and fewer drinks, not none. Other research on this site has looked at coffee’s links with lower risk of death and liver disease, which is worth reading alongside this study.

Bottom Line

In nearly 1 million UK adults, drinking tea and coffee very hot was linked to about 3 times the risk of esophageal squamous cell carcinoma compared with drinking them warm. Having 6 or more hot drinks a day was linked to about 71% higher risk, separately from temperature. Temperature had no clear link to adenocarcinoma. The authors estimate that 14% of squamous cell cases in UK adults could be avoided if very hot drinkers let their drinks cool to “hot.” Letting a cup cool for a few minutes is one of the simplest cancer prevention steps available.

Read the full study