Regular drinking of hot tea or coffee increases a person’s chances of developing cancer substantially, a study has found.
Latest research from the University of Cambridge found that consuming hot drinks almost triples the likelihood of a person contracting the disease in the oesophagus.
It builds on previous studies which have detected a similar link.
The researchers at Cambridge studied the health records of around 500,000 people in the UK to assess the risk of cancer in people who drink more coffee than others.
They found it increased the chances of developing one type of cancer — oesophageal.
People who were the most likely to consume coffee and tea were found to have a 2.8 times-higher risk than non-hot beverage drinkers.
Those who liked their coffee “hot” faced the highest risk, at 5.5 times, while people who preferred it “very hot” faced 4.1 times the risk and those who favoured it tepid were found to be at 2.7 times more risk.
The survey did not cover how much coffee a person drank, so it is not known whether volume was also a factor.
“There was evidence for a causal effect of coffee increasing oesophageal cancer, even in people who have self-reported preference for warm drinks,” study author Dr Stephen Burgess told The Daily Telegraph.
Experts have said a longstanding theory, stretching back to the 1930s, suggests hot drinks can destroy the inner lining of the oesophagus.
The process causes cells to continually regenerate, which creates a greater chance of errors that could turn cells cancerous, scientists say.
In 2016, the World Health Organisation issued a statement on the topic, which said that while a working group investigating the link had found “no conclusive evidence for a carcinogenic effect of drinking coffee”, experts said drinking very hot beverages “probably” caused cancer of the oesophagus in people.
Previous studies from China and Iran also found a link between hot drink consumption and oesophageal cancer, said Memorial Sloan Kettering Cancer Centre oncologist and gastroenterologist Smita Joshi in an online Q&A on the topic.
“The China study found a higher incidence of oesophageal cancer in people who drank more hot tea — but who also drank alcohol every day or smoked,” she said.
“I think all these conclusions were a bit misleading, at least as they apply to people in the United States and Europe. The type of oesophageal cancer that is far more common in the US is adenocarcinoma.
“The supposed link with hot beverages is related to an oesophageal cancer called 'squamous cell carcinoma'. This type is prevalent in many other parts of the world — China, other parts of Asia, India, South America and Africa — but is less common in the US and Europe.”
Dr Joshi advised anyone who is concerned about the link to allow their coffee or tea to cool for a few seconds before drinking it and focus on reducing other risk factors.
“I would advise people to focus more on factors that are very solidly linked to a higher risk of developing oesophageal cancer,” she said.
“For squamous cell, it’s smoking and alcohol. For adenocarcinoma, the most common risk factors are obesity and gastroesophageal reflux disease.”