Regularly drinking tea, coffee and other beverages while they are extremely hot may increase the risk of developing cancer of the oesophagus, commonly known as the food pipe, a new study has found.
Researchers from the University of Oxford analysed health data from nearly one million middle-aged men and women and found that people who regularly drank beverages at very high temperatures had about three times the risk of developing oesophageal cancer compared with those who drank their beverages warm.
The study, published in the International Journal of Cancer, described drinks heated to 65°C or above as “very hot”.
Researchers said repeated exposure to scalding-hot liquids could damage the lining of the oesophagus as the drink passes from the mouth to the stomach, potentially increasing the risk of cancer over time.
Drinking several hot beverages may increase risk
The study also found that consuming six or more hot drinks a day was associated with a higher risk.
However, experts stressed that oesophageal cancer remains relatively uncommon, meaning the overall chance of developing the disease is still low even among people who regularly consume very hot drinks.
Lead researcher Dr Keren Papier said previous research, including studies of people who drink very hot mate in South America, had also suggested a link between extremely hot beverages and oesophageal cancer.
She said further research was needed to establish more precisely which drink temperatures pose the greatest risk.
How hot is too hot?
A freshly prepared cup of tea or coffee can be much hotter than the temperature considered comfortable for drinking.
Water straight from a boiling kettle can reach about 100°C, while a freshly poured drink may still be around 90°C to 95°C.
Researchers therefore advise people to allow hot drinks to cool before drinking them.
Cancer Research UK said there is no specific amount of time that every drink needs to cool, but advised people to wait until the beverage is comfortable to drink rather than consuming it while it is still steaming hot.
Adding milk may lower the temperature slightly, but experts said a milky tea or coffee can still be dangerously hot if consumed immediately.
Cancer risk remains relatively low
Despite the association found in the study, researchers cautioned against assuming that drinking hot tea or coffee will automatically cause cancer.
Oesophageal cancer is relatively rare, and other established risk factors, particularly smoking and excessive alcohol consumption, have a much stronger link with the disease.
Fiona Osgun of Cancer Research UK said the most important steps people can take to reduce their risk are avoiding smoking and reducing alcohol consumption.
The researchers estimated that around one or two out of every 10 cases of oesophageal cancer could potentially be prevented if people stopped consuming beverages at extremely high temperatures.
Symptoms to watch out for:
Symptoms of oesophageal cancer can include persistent heartburn, indigestion, pain in the throat or chest, difficulty swallowing and unexplained weight loss.
Health experts advise people experiencing persistent or unusual symptoms to seek medical attention rather than assuming they are simply related to their diet.
For tea and coffee lovers, the message from the study is relatively simple: you do not necessarily have to stop drinking your favourite beverage, but allowing it to cool to a comfortable temperature before drinking may reduce a potentially avoidable risk.
BBC.
