A recent study has found that regularly drinking beverages like tea and coffee at very hot temperatures increases the risk of cancer of the food pipe or gullet, known as oesophageal cancer.
Researchers followed the participants for 14 years to examine the relationship between drinking very hot beverages and the two main types of oesophageal cancer: adenocarcinoma and squamous cell carcinoma (SCC).
The participants were asked how hot they usually preferred their drinks, with options including “very hot”, “hot”, “warm” and “do not drink hot drinks”.
The researchers based their findings on the participants’ descriptions of how hot their drinks were, rather than on the actual temperature of the drinks.
The study, which was conducted by Oxford University, defines any drink at 65 degrees celsius or above as “very hot” and potentially posing a health risk.
Researchers found that people who drank very hot beverages had about three times the risk of developing squamous cell carcinoma (SCC) compared with those who drank warm beverages.
It also found that consuming six or more hot drinks a day was linked to a 71% higher risk of SCC.
However, neither the temperature nor the frequency of hot drink consumption was strongly associated with an increased risk of adenocarcinoma (AC).
The study revealed that steaming hot liquid can damage the cell lining of the food pipe on the way down to the stomach.
The researchers also suggested that around one or two in every 10 oesophageal cancers could be avoided if people stopped drinking very hot beverages.
However, SCC is rare, affecting a few thousand people a year. In the UK, around 1% of the population has a lifetime risk of being diagnosed with this type of cancer.
So even if scalding hot drinks might increase someone’s risk, the chances of them developing the cancer are still low.
Also there are other said factors, such as smoking, which are a bigger risk for oesophageal cancer.
Fiona Osgun, the head of health information at Cancer Research UK, which funded the study, advised people to wait until hot drinks are at a comfortable temperature before drinking them.
“It’s difficult to put an exact time on how long a hot drink should be left to cool. But if you’re worried, we’d suggest just waiting until it’s comfortable to drink rather than drinking it while it’s still very hot,” Osgun said.
Muy-Teck Teh, a professor of molecular oral oncology at Queen Mary University of London, said the research’s limitation is that people’s perception of how hot their drinks are is subjective, making it difficult to determine whether the temperature itself causes the increased cancer risk.
“A key limitation, however, is that perceived drink temperature is inherently subjective, and it remains unclear whether individuals who tolerate or prefer very hot drinks have altered thermosensation or mucosal sensitivity that might itself reflect underlying biological predisposition to squamous cell carcinoma and lead them to prefer hotter drinks,” he said.
“This possibility cannot be excluded and complicates interpretation of causality.”
In 2016, the International Agency for Research on Cancer stated that drinking very hot beverages was “probably carcinogenic to humans” and a “probable” cause of oesophageal cancer.
