Tea is often associated with a number of health benefits.
If your daily drink is too hot, however, you may dramatically increase your risk of cancer, according to a new study.
Research published Wednesday in the International Journal of Cancer tracked the habits of more than 50,000 tea drinkers in Golestan, a province in northeastern Iran. Over a 10-year period, 317 new cases of esophageal cancer were developed.
The study found that those who drank more than 700 ml (almost 24 ounces) of tea a day at a temperature of 60 degrees Celsius (140 degrees Fahrenheit) had a 90 percent higher risk for esophageal cancer.
“Based on the results of our study, drinking hot tea is associated with an increased risk of esophageal cancer,” said Farhad Islami, the study’s lead author.
The American Cancer Society estimates about 17,650 new cases of esophageal cancer will be diagnosed in the United States in 2019. Americans typically drink beverages like coffee, tea and hot chocolate at temperatures lower than 149 degrees Fahrenheit, but in South America, Asia and Africa, tea is served much hotter, according to the organization.
However, beverages at restaurants may be served at higher temperatures, as was revealed in the infamous 1994 lawsuit against McDonald’s during which the company admitted to keeping its coffee at temperatures between 180 and 190 degrees Fahrenheit,
It’s the temperature not the type of beverage that poses a threat, although Islami noted that more research needs to be done on why hot beverages can cause cancer.
He said chronic thermal injury could cause inflammation that could lead to cancer or make it easier for carcinogens ingested through food or drink to penetrate the esophageal lining.
Previous studies have examined the link between hot beverages and cancer, including a 2018 China-based study published in Annals of Internal Medicine that found drinking hot tea, when combined with heavy alcohol and tobacco use, significantly increases the risk of esophageal cancer.
The World Health Organization, in 2016, said drinking coffee, tea and other beverages at temperatures hotter than 149 degrees Fahrenheit “probably causes cancer.”
However, Islami said these previous studies were limited because they were either based on self-reported perceptions of tea drinking temperature or were conducted after participants developed cancer.
“As there is no known health benefit from drinking very hot beverages, it will be reasonable to advise people in Golestan and elsewhere to wait for their hot beverages to cool down before drinking,” the study concluded.