Coffee and tea drunk very hot may increase the risk of oesophageal cancer

A study conducted by researchers at the University of Oxford shows that people who regularly drink tea, coffee, or other very hot liquids face an increased risk of oesophageal cancer. The research, cited by BBC, was carried out on nearly one million people and is considered the most comprehensive analysis to date on this subject.

The results show that those who habitually consume "very hot" drinks have approximately three times the risk of developing oesophageal cancer, compared to people who drink warm beverages that are not at extreme temperatures. Specialists note, however, that the overall risk of developing the disease remains low.

What "very hot" means

According to the study, published in the International Journal of Cancer, a drink is considered "very hot" when it reaches at least 65 degrees Celsius. The analysis included data from 977,282 middle-aged men and women. It was found that the risk increases further in people who drink six or more hot beverages per day.

High temperatures can damage the cells lining the oesophagus on its way to the stomach. Adding milk reduces the temperature, but the drink may still remain too hot to consume safely. As a reference point: freshly boiled water reaches approximately 100 degrees Celsius, and tea or coffee poured immediately into a cup can be 90–95 degrees.

Specialists' recommendations

Researchers advise waiting a few minutes before drinking a hot beverage, to allow the temperature to drop. Cancer Research UK states that there is no exact timeframe that applies to all cases, but recommends waiting until the drink can be consumed comfortably, without it being very hot.

Dr Keren Papier, the study's lead researcher, explained that previous research in South America, where maté is frequently consumed at high temperatures, had shown a similar link to oesophageal cancer. She stressed, however, that further studies are needed to more precisely establish the temperature thresholds associated with increased risk.

How hot is "too hot"

Another study, in which 118 young adults repeatedly tasted black coffee at various temperatures, showed that the majority considered the drink too hot from around 70 degrees Celsius. For coffee served in cafés, one cup manufacturer recommends an ideal temperature of between 49 and 60 degrees Celsius, though an "extra hot" order can exceed 82 degrees.

Increased individual risk, but a rare disease

According to the researchers' estimates, between one and two in ten cases of oesophageal cancer could be prevented if people stopped consuming very hot drinks. Squamous cell oesophageal cancer remains a rare form of the disease, affecting several thousand people each year. In the United Kingdom, the lifetime risk of being diagnosed with this form of the disease is approximately 1%.

Other significant risk factors

Smoking and alcohol consumption remain more significant risk factors for oesophageal cancer. Fiona Osgun, a representative of Cancer Research UK, emphasised that quitting smoking and reducing alcohol intake are the most important steps for lowering the risk. Possible symptoms of the disease include heartburn, indigestion, pain in the throat or chest, and weight loss.