According to a new study reported by CNN, drinking very hot coffee or tea could nearly double a person's risk of esophageal cancer.
The study, lead by Dr. Farhad Islami of the American Cancer Society, found that people who drink 700 ml or more of tea daily (around two cups) at 60 degrees Celsius (140 degrees Farenheit) or hotter have a 90% higher risk of esophageal cancer versus those who drank less tea or drank it at a slightly colder temperature.
"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. Islami concluded.
The study examined over 50,000 people in the Irani province of Golestan. Researchers chose to conduct the study in Iran thanks, in part, to its history of extremely hot tea consumption. While Americans and Europeans rarely drink tea above 65 degrees Celsius (149 degrees Fahrenheit), it's common in places like the Middle East, Russia, and South America to drink it much hotter.The temperature difference is due partly to the practice of drinking tea out of a constantly heated samovar -- in the United States and England, tea is served in a room-temperature mug and allowed to cool naturally.
As a previous CNN story indicates, prior research has already suggested a connection between consumption of extremely hot beverages and increased cancer risk, but this new study was reportedly the first to name a specific temperature threshold for the increased danger.
Esophageal cancer is among the top 10 most prevalent forms of cancer, with over 572,000 new cases per year. It's also one of the more deadly cancer varieties -- The World Health Organization's International Agency for Research on Cancer estimates that esophageal cancer kills over 500,000 people annually.
Esophageal cancer has long been linked with repeated stress on the esophagus caused by behaviors like excessive smoking and drinking. This new research suggests that any extremely hot liquid may pose a similar risk.
Dr. James Doidge of the University College London concurred, noting that extremely hot drinks were an established risk factor for esophageal cancer.
"It doesn't take a scientist to appreciate that repeated irritation of any body surface increases your risk of cancer. Sunburn gives us skin cancer, smoking gives us lung cancer, and many foods and drinks contribute to risk of gastrointestinal cancers," Doidge said to the Science Media Centre.
A cup or two of hot coffee or tea in the morning is a daily ritual for millions of people worldwide. But as the research continues to build a link between excessively hot coffee and tea and increased risk of cancer, it might be time to slow down on the habit.