There is sufficient proof to suggest drinking “very hot” beverages can lead to cancer, says the World Health Organization.
A study from the International Agency for Research on Cancer released on Wednesday states beverages at temperatures above 70 degrees Celsius (160 degrees Fahrenheit) are “probably carcinogenic,” regardless of the ingredients in them. But drinking beverages at “normal serving temperature” under 65 degrees Celsius pose no threat to humans.
“Most people in the U.K. don't consume drinks at the temperatures considered in this research, although very hot tea is a popular drink in Middle Eastern and other countries,” said Casey Dunlop, health information officer at Cancer Research U.K. “There is some evidence that drinking very hot drinks over 65ºC may increase the risk of esophageal cancer. So as long as you let your drink cool down a bit before you drink it, you're unlikely to be much at risk.”
The report cited countries including China, Iran and those of South America and Middle East — where bitter infusions of tea are served at temperatures way above 70 degrees Celsius and are much hotter than ones served in Western cafes — are at particular risk.
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Dana Lewis, deputy head of the IARC program, suggests such hot beverages may be the cause of “thermal injuries” to the throat, which could result in a growth of tumors, but the evidence was limited. He also said there is insufficient evidence to suggest if eating very hot food could be dangerous as well.
The IARC also notes that coffee, which was once thought to be carcinogenic, is relieved of the stigma 25 years later, based on the results of more than 1,000 studies.
“I’m not really sure why coffee was in a higher category in the first place,” said Owen Yang, an epidemiologist at Oxford University who has studied the possible link between coffee and cancer. “The best evidence available suggests that coffee does not raise the cancer risk.”
In fact, the American Institute of Cancer Research states coffee may even provide protection from liver and endometrial cancer.
However, other cancer researchers think experts should focus on the leading causes of cancer rather than on hot drinks that may or may not cause the disease.
“Quitting smoking and reducing alcohol consumption are much more significant for reducing cancer risk than the temperature of what you’re drinking,” said Otis Brawley, chief medical officer of the American Cancer Society, who has likened cancer risk by hot beverages to that posed by pickled vegetables. But as an avid coffee drinker, he is relieved to see that coffee is off the list of carcinogenic.
The IARC report makes no mention of how many hot beverages it would take to significantly increase one’s chances of cancer.