Study links hot drinks to oesophageal cancer

Adding cold milk to tea and coffee and waiting for hot drinks to cool could protect against oesophageal cancer, a study suggests.

Research has found that regularly swallowing hot drinks nearly doubles the risk of developing diseases of the gullet and researchers have advised people to allow beverages to cool. In 2016, the World Health Organisation first warned of the cancer risk associated with drinks above 65 degrees Celsius.

Now a study of 50,000 people, published in the Journal of Cancer, has found that drinking 700ml a day of tea (about three cups) at 60C or higher appears to be ‘‘consistently associated’’ with a 90 per cent increased risk of contracting the disease, compared with people who consumed drinks at lower temperature. Between 2004 and 2017, 317 new cases of oesophageal cancer were identified within the test group, with the chance of developing the disease far higher for people consuming hot drinks.

Dr Farhad Islami said: ‘‘Many people enjoy drinking tea, coffee, or other hot beverages. But according to our report, drinking very hot tea can increase the risk of oesophageal cancer. It is therefore advisable to wait until hot beverages cool down before drinking.’’

The lifetime risk of getting oesophageal cancer in a man is 1 in 55.

The new research suggests that would virtually double for men who drink very hot beverages.

The carcinogenic effect is likely to stem from repeated scalding of the food pipe, which damages cells.

Alcohol and smoking have a similar impact on cells and can also cause oesophageal cancer.

Previous studies have found that smokers and drinkers who drink hot tea are more at risk of cancer of the gullet.

However, the study was carried out on people living in Iran, where tea and coffee is drunk far hotter than in Britain. An article published in the journal in 2016 found that a cup of tea with 10ml of milk cooled to less than 65C in under five minutes. Allowing tea to cool to 60C is unlikely to affect the taste, according to research.

The Royal Society of Chemistry also recommends drinking tea at 60C to 65C, while Northumbria University found the perfect drinking temperature of tea – 60C – was achieved six minutes after preparation.

Most coffee experts recommend the drink be served at 40C to 60C.

Georgina Hill, the health information officer at Cancer Research UK, said: ‘‘This study adds to the evidence that having drinks hotter than 60 degrees may increase the risk of oesophageal cancer, but most people in the UK don’t drink their tea at such high temperatures. As long you’re letting your tea cool down a bit before you drink it, or adding cold milk, you’re unlikely to be raising your cancer risk.

‘‘Not smoking, keeping a healthy weight and cutting down on alcohol will do much more to stack the odds in your favour.’’

A cup of tea with 10ml of milk cooled to less than 65C in under five minutes.