Coffee warning as drinking it this way could increase risk of cancer by 6 times

Regularly drinking tea or coffee at very hot temperatures may increase the risk of cancers affecting the oesophagus, the tube that carries food from the throat to the stomach. A study using data from more than 450,000 members of the UK Biobank found those who drank eight more cups of very hot tea or coffee per day were almost six times more likely to be diagnosed with oesophageal squamous cell carcinoma (ESCC) over an average follow-up period of 12 years, compared to those who did not consume hot drinks.

Participants were asked to rate the their preferred temperature of hot beverages. Some 17% selected “very hot”, 66.5% said “hot”, and 15.3% said “warm”. Women were more likely than men to select “very hot”, which could be defined as a temperature greater than 65C, the researchers said.

An increased risk was also seen for people who drank more than eight cups per day.

Risk increased by 2.52 times for those who drank four or more very hot drinks per day, 3.67 times for those who drank four to six cups, and 4.75 times for those who drank six to eight cups.

Writing in the British Journal of Cancer, the researchers concluded: “We found that tea and coffee drinkers in the UK who preferred their beverages hot or very hot, had a higher incidence of ESCC relative to those who did not drink hot beverages or preferred to drink them warm.”

The experts noted that the biological explanation for this link between very hot drinks and risk of oesophageal cancer was unclear.

But they added: “One hypothesis is that habitual exposure to very hot beverages causes cell injuries that contribute to the development of cancer in the oesophagus.

“An animal study showed that ingesting very hot water (70°C) had a tumour promoter effect on oesophageal hyperproliferative premalignant lesions in rats.”

A similar study in 2019 of people living in Iran found that people who drank tea at or above 60C had an increased risk of oesophageal cancer.

Cancer Research UK noted at the time that 60C was likely to be “a lot hotter than most cups of tea”.

The charity’s analysis added: “If you’re leaving your tea to cool for a few minutes before drinking it, even while it’s brewing, or adding cold milk, it’s unlikely that you’re increasing your risk of oesophageal cancer.”