Drinking hot tea may be a common habit, but a new study reveals a link between scalding tea and an increased risk of esophageal cancer.
While previous papers have already linked hot tea and esophageal cancer, it's the first time that scientists have examined the connection with a specific temperature in mind.
Burning Tea Doubles Cancer Risk
The new study, published in the International Journal of Cancer, followed 50,045 individuals in Iran who ranged from 40 to 75 years old for an average period of 10 years.
Among the participants, 317 cases of esophageal cancer were identified during the follow-up.
Researchers discovered that people who drink more than 700 ml of tea hotter than 60 degrees Celsius (140 degrees Fahrenheit) every day are at a 90 percent higher risk of esophageal cancer than those who drink less and prefer their cups at cooler temperatures.
"Many people enjoy drinking tea, coffee, or other hot beverages. However, according to our report, drinking very hot tea can increase the risk of esophageal cancer, and it is therefore advisable to wait until hot beverages cool down before drinking," Dr. Farhad Islami, lead author from the American Cancer Society, said.
Heat Likely The Factor Behind Link
In the study, the team explains that their findings support the link between hot beverages and esophageal cancer. However, they also recommend further studies on the reason behind the connection.
Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine who was not involved with the study, theorizes that heat was the factor rather than the nature of the beverage.
"In fact, it is probably anything hot: Microwaved jam has been known to cause esophageal injury. It is possible that the trauma leads to cell changes and hence to cancer," Evans tells the Science Media Centre, according to CNN.
About Esophageal Cancer
As of 2019, the American Cancer Society estimates a total of 17,650 new cases of esophageal cancer and 16,080 deaths from the disease.
While this type of cancer makes up just 1 percent of all cancers diagnosed in the United States, it's a lot more common in other countries such as Iran, China, southern Africa, and India. Specifically, esophageal cancer is the eighth most common cancer in the world, according to data from the International Agency for Research on Cancer.
Survival rate has improved over the years. In 2019, about 20 percent of all patients with esophageal cancer now survive at least five years after diagnosis.