Drinking ‘very hot’ drinks may increase risk of esophageal cancer: study

A new study from the University of Oxford in the U.K. found that participants who said they drank “hot” or “very hot” drinks may have a higher risk of developing a type of esophageal cancer.

Scientists outside the U.K. have been studying a possible correlation for years, Cancer Research U.K. — which funded the research — noted.

“International research has shown for some time that drinking beverages like mate at very high temperatures, as is typical in South America, is linked to increased risk of certain oesophageal cancers,” Dr. Keren Papier, lead researcher and senior nutritional epidemiologist at Oxford Population Health, told the charity.

Mate is a caffeinated herbal beverage similar to tea, but made with the yerba mate plant.

“What was less clear was whether this also applied to the temperatures at which hot drinks are usually consumed in Western populations,” she added.

Papier and her team of researchers analyzed data from almost one million British adults to identify possible signs of a similar link to the development of esophageal squamous cell carcinoma (SCC) in the U.K.

Esophageal SCC is relatively rare in the U.K. to begin with, with people having around a one per cent lifetime risk of being diagnosed, so even if a person’s risk increases slightly from very hot drink consumption, it will likely remain low overall, the study notes.

In Canada, there are approximately 33.5 diagnoses of the same type of cancer per million individuals per year, or about 2,800 people in total. Although it is rare here too, survival rates are less than 20 per cent.

In the study, participants reported whether they typically drank drinks “very hot,” “hot,” or “warm.”

The researchers tracked participants’ health for over 10 years to see whether they developed esophageal SCC. Findings indicated that consuming scalding hot drinks over a long period of time could damage the lining of the esophagus, which may increase the risk of developing cancer.

Compared with those who said they consumed their drinks “warm,” researchers found that those who preferred their beverage “hot” had a nearly two-times higher risk of developing esophageal SCC, while those who drank them at “very hot” temperature had a three-times higher risk.

“This is now the largest study to look at that question in a U.K. population, where many people drink tea and coffee daily,” Papier said.

“It adds to existing evidence that drinking very hot drinks could increase the risk of oesophageal squamous cell carcinoma.”

The study did not find a correlation between tea or coffee consumption and an increased risk of developing esophageal SCC; the risk is associated with the temperature of any hot drink.

The International Agency for Research on Cancer considers a beverage “very hot” if it is above 65 degrees Celsius, and says it is “probably carcinogenic” to people.

Average serving temperatures of tea and coffee are generally between  71–85 degrees Celsius but are usually consumed at lower temperatures, typically 50–70 degrees Celsius, according to a study in the National Library of Medicine.

There are no specific laws or regulations in Canada requiring hot drinks to be served within a certain temperature range, though businesses can face legal liability if they serve a drink at an unreasonably high temperature.