Ah, tea — it’s the most widely consumed drink in the world, and a staple of the Asian (and, indeed, global) diet and lifestyle.
A team of researchers from Iran found that tea drinkers who preferred their beverage at temperatures of 60 degrees Celsius (140 degrees Fahrenheit) or higher and drank more than 700 ml (roughly two large cups) a day had a 90% higher risk of developing esophageal cancer compared to those who consumed less tea and at cooler temperatures.
The study examined 50,045 individuals aged 40 to 75 in Golestan, a province in northeastern Iran, for a median period of 10 years. The researchers detected 317 new cases of esophageal cancer from 2004 to 2017.
“Many people enjoy drinking tea, coffee, or other hot beverages,”
said lead author Dr. Farhad Islami
, who serves as the strategic director of the American Cancer Society (AMC). “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,”
While previous research has observed the link between hot tea consumption and esophageal cancer, the present study — published this Wednesday in the International Journal of Cancer — was the first to specify ranges of temperature.
Esophageal cancer is a cancer of the esophagus, the pipe through which swallowed food and liquids travel towards the stomach. According to the International Agency for Research on Cancer, it is the eighth most common cancer in the world, killing approximately 400,000 people every year. It is generally caused by repeated aggravation to the esophagus by smoke, alcohol, acid reflux and, apparently, heat.
The findings are particularly relevant for tea drinkers in regions where the beverage is customarily served hot, contrasting with the United States and Western Europe, where tea is usually consumed after having cooled down significantly.
“If you go to the Middle East or to Russia, they drink it out of a samovar that’s constantly under heat,”
Peter Goggi, president of the Tea Association of the USA, told CNN in 2018
. “It’s very, very hot.”
But even if you don’t drink your tea at tongue-burning temperatures, there’s still something to take away from this. Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine who was not involved with the research, believes the findings in the study have less to do with tea — or any other beverage or food for that matter — but with the heat.
“In fact, it is probably anything hot: Microwaved jam has been known to cause esophageal injury,” he was quoted as saying by the Science Media Centre. “It is possible that the trauma leads to cell changes and hence to cancer.”
Images via Pixabay