Recent research highlights a concerning link between the consumption of very hot beverages and an increased risk of certain cancers, particularly oesophageal cancer. In a study involving nearly half a million adults in the United Kingdom, those who regularly consumed very hot tea or coffee were found to be almost six times more likely to develop this type of cancer compared to individuals who did not consume hot drinks.
The International Agency for Research on Cancer classified beverages served above 65°C as “probably carcinogenic to humans” back in 2016. This categorization places them in the same risk bracket as indoor wood smoke and high consumption of red meat. The classification is based on evidence indicating that it is the temperature of the drink, rather than the beverages themselves, that poses the health risk.
Understanding the Risks
The primary concern lies with the oesophagus, or food pipe. Research, particularly from regions in South America, has linked the consumption of very hot maté, traditionally served around 70°C, to an elevated risk of oesophageal cancer. Similar findings have emerged from studies conducted in the Middle East, Africa, and Asia, reinforcing the connection between the consumption of hot beverages and cancer development.
A recent study in the UK added to the existing body of research by confirming that drinking higher volumes of very hot drinks correlates with increased cancer risk. The study’s findings suggest that individuals consuming eight or more cups a day of very hot beverages are significantly increasing their likelihood of developing oesophageal cancer.
The mechanism behind this risk involves the damage that very hot drinks can inflict on the cells lining the oesophagus. Over time, repeated exposure to high temperatures may lead to changes that foster cancer development. Evidence gathered over nearly a century supports this theory, with animal studies indicating that exposure to hot water can accelerate cancer growth.
How Temperature Affects Your Health
Research indicates that the quantity and temperature of hot drinks consumed in a single sitting also play critical roles in the risk of oesophageal damage. A study measuring the temperature inside the oesophagus revealed that larger sips can raise internal temperatures significantly. For instance, a sip of 65°C coffee can increase oesophageal temperature by up to 12°C, potentially causing lasting heat-related injuries.
To mitigate risks, understanding the optimal drinking temperatures is essential. While brewing temperatures for beverages like coffee can approach boiling point, a study from the United States identified an ideal temperature of 57.8°C. This balance allows for flavour preservation while reducing the risk of heat injury.
To safely enjoy hot beverages, experts recommend a few strategies. Taking time to let drinks cool, which can drop their temperature by 10–15°C within five minutes, is beneficial. Additionally, sipping slowly and testing temperatures with smaller amounts can help avoid potential damage to the oesophagus.
Vincent Ho, an Associate Professor and Clinical Academic Gastroenterologist at Western Sydney University, emphasizes the importance of moderating beverage temperatures to protect long-term health. Adopting these practices can allow individuals to enjoy their favourite hot drinks while minimizing associated health risks.
