Oxford study involving nearly 1 million people links very hot drinks to a higher risk of oesophageal squamous cell carcinoma
Oxford: A large study involving nearly one million people has found a significant association between drinking very hot beverages and an increased risk of a type of oesophageal cancer.
Researchers from the University of Oxford found that people who reported drinking their tea, coffee or other beverages at very high temperatures had a substantially higher risk of developing oesophageal squamous cell carcinoma (SCC) compared with those who preferred their drinks warm or lukewarm.
The study included 977,282 middle-aged men and women and is among the largest investigations to examine the relationship between beverage temperature and oesophageal cancer risk. The findings were published in the International Journal of Cancer.
Very Hot Drinks Linked to Nearly Threefold Higher Risk
According to the research, participants who reported drinking beverages as “very hot” had around three times the risk of oesophageal squamous cell carcinoma compared with those who drank them at a warm temperature.
Importantly, the study does not suggest that tea or coffee itself is responsible for the increased risk. Instead, the association appears to be related primarily to how hot the beverage is when consumed. Cancer Research UK, which reviewed the findings, also noted that the study did not measure the actual temperature of the drinks consumed by participants.
Scientists believe that repeatedly exposing the oesophagus to very hot liquids may cause thermal injury to its lining. Over time, repeated irritation and damage could potentially contribute to the development of cancerous changes.
What Temperature Is Considered ‘Very Hot’?
The 65°C threshold often mentioned in discussions about very hot beverages comes from the International Agency for Research on Cancer (IARC), which has classified beverages consumed above 65°C as probably carcinogenic.
However, the new Oxford study did not measure the actual temperature of the drinks. Participants reported whether they usually consumed beverages as warm, hot or very hot. Therefore, 65°C should not be treated as an exact safety cut-off established by this study.
Earlier research has also reported a relationship between high-temperature beverage consumption and oesophageal squamous cell carcinoma. A prospective study published in the International Journal of Cancer found that objectively measured tea temperatures of 60°C or higher were associated with increased risk, further supporting the importance of allowing very hot drinks to cool before drinking them.
Drinking Frequency May Also Matter
The Oxford research also examined how frequently people consumed hot beverages. The findings suggest that people drinking large quantities of hot beverages may have a higher risk, although researchers caution against treating a particular number of cups as a definite “danger threshold.”
The key concern appears to be repeated exposure to high temperatures, rather than simply drinking tea or coffee.
Should You Stop Drinking Tea or Coffee?
Not necessarily.
The findings do not mean that people need to give up tea or coffee altogether. The practical takeaway is to avoid drinking beverages while they are hot enough to burn the mouth or throat.
Allowing freshly prepared tea or coffee to cool for a few minutes before drinking can reduce the temperature and may help avoid repeated thermal injury to the oesophagus.
Cancer Research UK advises people to drink hot beverages when they are at a comfortable temperature. The organisation also points out that there is no precise evidence-based waiting time that applies to every cup, because cooling depends on factors such as the drink, cup and surrounding temperature.
Why the Oesophagus Matters
The oesophagus, commonly called the food pipe or swallowing tube, carries food and liquids from the mouth to the stomach.
Repeated exposure to very hot liquids may injure the cells lining this passage. Researchers believe that this type of repeated thermal damage could be one mechanism behind the observed association between very hot drinks and oesophageal squamous cell carcinoma.
However, the overall risk of developing this cancer remains relatively low, and temperature is only one of several possible risk factors.
Smoking and Alcohol Remain Important Risk Factors
Experts stress that people should not overlook better-established risk factors for oesophageal cancer.
Smoking and alcohol consumption are important risk factors, and reducing or avoiding them remains a much more established way of lowering cancer risk.
Symptoms of oesophageal cancer can include:
- Persistent heartburn or acid reflux
- Indigestion
- Pain or discomfort in the throat or chest
- Difficulty swallowing
- Unexplained weight loss
These symptoms can have many causes and do not necessarily indicate cancer. However, persistent or worsening symptoms should be discussed with a doctor.
The Bottom Line
The latest Oxford research adds to growing evidence that regularly drinking beverages at very high temperatures may increase the risk of oesophageal squamous cell carcinoma.
The message is not to stop drinking tea or coffee, but to avoid consuming them when they are extremely hot. Giving a freshly prepared drink a few minutes to cool before taking a sip is a simple precaution.
At the same time, the study should be interpreted carefully. It shows an association rather than proving that very hot drinks directly cause cancer, and the actual temperatures consumed by participants were not measured.
