A study published this week in Annals of Internal Medicine shows that hot teas, in conjunction with other risk factors, can increase the chances of developing esophageal cancer, according to Gizmodo.com.
The researchers used data from the ongoing China Kadoorie Biobank study, which has tracked physical measurements and health issues for over half a million residents of China, starting from 2004 to 2008, and keeping track of health outcomes since then. The new research looks at 400,000 individuals who were cancer free at the start of the study, and the 1,731 who had been diagnosed with esophageal cancer by 2015.
They found that those who drank more than a standard serving of alcohol each day, and also drank hot tea were more than five times as likely to develop this type of cancer as those who consumed hot tea and alcohol less than once a week. Smokers who also drank hot tea were twice as likely to be diagnosed with cancer. Those who drank alcohol, smoked cigarettes, and also drank hot tea faced even higher risk.
According UCLA clinical nutrition associate professor Catherine Carpenter:
“I think the results are really important. There isn’t any question about whether tea in of itself is carcinogenic. It’s not about that, it’s about having a lifetime history of drinking very hot beverages.”
She also noted that regular tea consumption has been connected to a lower risk of certain types of cancer, adding;
“Probably all cancers have more than one cause, and what makes it so challenging that some people can develop the same cancer, but for different reasons. That’s what makes the study of cancer so hard.”
Other studies, however, have shown some increased cancer risk associated with hot drinks alone. That evidence led the International Agency for Research on Cancer to designate hot beverages as “probably carcinogenic” to humans, in 2016.
Gender also seemed to play a part in the cancer risk found by the study, with men more likely to develop esophageal cancer alongside a habit of drinking hot tea. But men in the study also were broadly more likely to drink tea, especially alongside alcohol and smoking habits. In the study, 40 percent of men drank tea regularly, compared to only 16 percent of women.
In general, esophageal cancer is fairly rare. Only 0.5 percent of people will be diagnosed with esophageal cancer in their lifetimes, compared with 12 percent of women who will be diagnosed with breast cancer.