Esophageal cancer is the eighth most common cancer in the world and is often fatal, killing approximately 400,000 people every year, according to the International Agency for Research on Cancer. It is usually caused by repeated injury to the esophagus due to smoke, alcohol, acid reflux and — maybe — hot liquids.
The esophagus is a long tube through which swallowed food and liquids travel to reach the stomach.
The American Cancer Society estimates that 13,750 new cases of esophageal cancer will be diagnosed in men and 3,900 new cases in women in the United States in 2019.
The team of researchers followed 50,045 people, aged between 40 and 75, for an average of 10 years. Between 2004 and 2017, the researchers detected 317 new cases of oesophageal cancer.
The study said more research was needed on why exactly drinking very hot tea is associated with the higher risk of esophageal cancer.
Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said that it was the heat that was the issue rather than the type of beverage.
“In fact, it is probably anything hot: Microwaved jam has been known to cause oesophageal injury. It is possible that the trauma leads to cell changes and hence to cancer,” he told the Science Media Centre. Evans was not involved in the study.
In the United States and Europe, tea is rarely consumed at temperatures above 65 degrees Celsius (149 degrees Fahrenheit) — but in places like Russia, Iran, Turkey and South America, it is common to drink tea that hot or even hotter.
“If you go to the Middle East or to Russia, they drink it out of a samovar that’s constantly under heat,” said Peter Goggi, president of the Tea Association of the USA told CNN last year. “It’s very, very hot.”
Dr. James Doidge, senior research associate at University College London, said that hot drinks were an established risk factor for oesophageal 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, who wasn’t involved in the research, told the Science Media Centre.