A steaming cup of tea or coffee may feel comforting, familiar and harmless. New evidence suggests that the temperature of that drink could matter more than many people realise.

A large UK study has found that regularly drinking beverages described as “very hot” was linked with a substantially higher risk of oesophageal squamous cell carcinoma, a serious form of oesophageal cancer. People who said they preferred very hot tea or coffee had more than three times the risk of this cancer compared with those who drank their beverages warm.

The findings were published recently in the International Journal of Cancer. They add weight to a growing body of research indicating that repeated heat injury to the lining of the oesophagus (the muscular food pipe that carries what you eat and drink from the back of your throat down to your stomach) may contribute to cancer over many years.

Oesophageal cancer is a leading cause of cancer-related mortality in Malaysia. Although relatively uncommon, with an overall age-standardised incidence of approximately 1.89–2.0 cases per 100,000 population, it carries a poor prognosis (outcomes). More than 50%–70% of patients are diagnosed at an advanced stage (Stage IV), contributing to its high mortality rate.

“Compared with people who drank warm tea or coffee, those who drank very hot beverages had a pooled relative risk of 3.17. In practical terms, this means their risk was more than three times higher”

The message for tea and coffee drinkers is straightforward. There is no need to abandon hot drinks altogether. Letting them cool before the first sip may be a sensible, low-effort health precaution, regardless of types of beverages.

The research brought together data from two major UK studies: the Million Women Study and UK Biobank. In total, scientists assessed almost one million adults aged between 37 and 73. Participants answered questions about their usual tea and coffee habits, including whether they preferred their drinks warm, hot or very hot. They also reported how many hot beverages they drank each day.

“People who drank six or more cups of hot tea or coffee each day had a 71% higher risk of oesophageal squamous cell carcinoma than those who drank fewer than six cups daily“

Researchers followed participants for more than a decade. Health records linked through the NHS were used to identify new diagnoses of oesophageal cancer. During follow-up, there were 2,348 cases of oesophageal cancer. Of these, 1,045 were squamous cell carcinoma and 1,303 were adenocarcinoma, another common type of oesophageal cancer.

The clearest association concerned squamous cell carcinoma. Compared with people who drank warm tea or coffee, those who drank very hot beverages had a pooled relative risk of 3.17. In practical terms, this means their risk was more than three times higher. Participants who preferred drinks described as hot, rather than very hot, also had an increased risk, though the association was smaller.

The results did not show the same pattern for oesophageal adenocarcinoma (a different type of oesophageal cancer). Drink temperature appeared to make little difference to the risk of that form of cancer. This distinction is important because the two cancers arise in different types of oesophageal cells and have different leading risk factors.

Squamous cell carcinoma tends to affect the upper or middle part of the oesophagus. Tobacco use and heavy alcohol consumption are well-established contributors. Adenocarcinoma occurs more often in the lower oesophagus and is strongly associated with chronic acid reflux, Barrett’s oesophagus and excess body weight.

The study also found a possible role for the number of hot drinks consumed. People who drank six or more cups of hot tea or coffee each day had a 71% higher risk of oesophageal squamous cell carcinoma than those who drank fewer than six cups daily. This result remained after scientists accounted for beverage temperature and other relevant factors.

The association with frequent consumption was weaker and less certain for adenocarcinoma. Researchers reported only a modest increase in risk, one that was not as clearly distinguished from chance.

These findings should not be interpreted as proof that hot tea or coffee directly causes cancer in every case. This was an observational study. It can identify associations across large populations, yet it cannot establish direct cause and effect with the certainty of a clinical trial.

There are also practical limits to the research. Participants described their usual drinking temperature rather than having each cup measured with a thermometer. One person’s “hot” drink may be another person’s “very hot” drink. Personal tolerance varies. Cup type, milk, room temperature, drinking speed and the time allowed for cooling can all influence the temperature of a beverage by the time it reaches the oesophagus.

Even so, the findings are notable because of the study’s scale, duration and consistency.

The increased risk associated with very hot drinks appeared across groups with different smoking habits, alcohol intake and milk use. That supports the possibility that repeated exposure to excessive heat itself may be harmful.

Scientists have long considered very hot beverages a potential cancer risk. The International Agency for Research on Cancer, part of the World Health Organization, has classified drinking beverages at temperatures above about 65 degrees Celsius as “probably carcinogenic to humans”. This classification does not mean every hot drink is dangerous. It reflects evidence that regularly consuming scalding liquids can damage the oesophagus.

“Allowing a drink to cool down a bit is one of the simplest changes people can make. It costs nothing. It does not require giving up tea, coffee or other warm drinks. It may reduce a repeated source of injury that can otherwise go unnoticed”

The biological explanation is plausible. The oesophagus is the muscular tube that carries food and drink from the mouth to the stomach. When exposed repeatedly to very high temperatures, its delicate inner lining can suffer minor burns and tissue injury. The body repairs this damage. If the process happens often, chronic inflammation and repeated cell turnover may follow.

Over time, such conditions could make abnormal cell changes more likely. Cancer usually develops through a complex mix of genetic susceptibility, environmental exposures and cumulative tissue damage. Heat may be one piece of that wider picture.

The risk from hot drinks should also be kept in perspective. A threefold relative increase can sound alarming. Individual risk still depends on a person’s age, medical history, smoking, alcohol use, diet, weight, reflux symptoms and other factors. Oesophageal cancer remains relatively uncommon compared with many other cancers, though it can be difficult to detect early and often has serious consequences.

For people who smoke or consume alcohol heavily, reducing or stopping these habits is likely to have a far greater effect on oesophageal cancer risk than changing tea-drinking routines alone.

Managing longstanding heartburn or reflux is also important, particularly because persistent reflux can damage the lower oesophagus and increase the risk of adenocarcinoma.

Still, allowing a drink to cool down a bit is one of the simplest changes people can make. It costs nothing. It does not require giving up tea, coffee or other warm drinks. It may reduce a repeated source of injury that can otherwise go unnoticed.

A practical approach is to wait several minutes after pouring or buying a hot beverage. Stirring the drink can help distribute heat more evenly. Adding cold milk or water lowers the temperature quickly. Small, cautious sips are wiser than swallowing a mouthful immediately after a drink has been served.

A useful rule is to pay attention to the tongue. If a sip burns, numbs or causes discomfort, it is too hot to drink. The absence of severe pain should not be taken as reassurance, however. A person may tolerate a drink in the mouth while the oesophagus still receives more heat than is advisable.

Takeaway coffee cups can present a particular problem. Their lids retain heat, while insulation can keep drinks hot for longer than expected. A drink bought on the commute may remain near-scalding several minutes later. Removing the lid where safe, stirring carefully and waiting before drinking can make a meaningful difference.

The study’s population-level estimate suggests that a notable proportion of oesophageal squamous cell carcinoma cases in the UK could potentially be avoided if people who currently drink beverages very hot reduced the temperature to merely hot. Researchers estimated that around 14% of these cancers, equivalent to roughly 440 UK cases each year in this particular study, might be preventable under that scenario.

That estimate is based on statistical modelling, not a guarantee. Yet it illustrates the potential public-health relevance of a habit that is easy to overlook. Much cancer prevention advice focuses on major lifestyle changes. Those remain essential. The temperature of a daily drink is a smaller detail, though it may still matter when repeated thousands of times over decades.

Tea and coffee have also been studied for possible health benefits, including associations with lower risks of some chronic diseases in certain populations. This research does not overturn those findings. It shifts attention away from the beverage itself and towards how it is consumed.

For most people, the sensible response is moderation rather than worry. Enjoy tea or coffee. Do not rush it. Give it time to cool.

Anyone experiencing ongoing difficulty swallowing, pain when swallowing, unexplained weight loss, persistent indigestion, vomiting, chest discomfort or black stools should seek medical advice promptly. These symptoms do not necessarily indicate cancer, but they deserve assessment, especially if they persist or worsen.

The new study offers a clear public-health reminder. Daily rituals can carry hidden risks when heat is involved. A cup of tea does not need to be lukewarm to be safe or enjoyable. It simply should not be hot enough to burn.