It's a specific health warning for a specific group of people: If you smoke, drink alcohol, and also happen to drink tea, let the latter cool down before you drink it. Failing to do so might raise your risk of esophageal cancer, suggests a study in the Annals of Internal Medicine by Chinese researchers. The idea is that hot tea (or, presumably, any hot beverage) can damage cells in the esophagus and make it more vulnerable to the damage caused by cigarettes and alcohol, the lead researcher tells the Telegraph. How hot is too hot? The researchers didn't specify, but CNN notes that previous research on hot beverages pegged the danger zone at 149 degrees Fahrenheit and above.
"Irritating the lining of the esophagus could lead to increased inflammation and more rapid turnover of the cells," explains a National Cancer Institute investigator who was not involved with the study. "Alternatively, hot liquids may impair the barrier function of the cells lining the esophagus, leaving the tissue open to greater damage from other carcinogens." The observational study was a massive one, following nearly 500,000 Chinese adults ages 30 to 79 for about a decade. Those who drank hot tea and either smoked or used alcohol, but not both, also saw an increased risk of cancer, though it wasn't as great, reports Time. And hot tea alone did not carry a significant risk increase.