Drinking hot tea tied to higher risk of oesophageal cancer
Drinking burning hot tea is associated with an increased risk of oesophageal cancer in men, especially in those who also smoke and drink, a study suggests.
However, the association was attenuated in the absence of smoking and excessive drinking—suggesting that abstaining from hot tea may help prevent oesophageal cancer in smokers and drinkers.
The prospective cohort involved 456,155 participants aged 30–79 years in the China Kadoorie Biobank who self-reported their tea consumption behaviours, including frequency, amount, type, and temperature of tea consumed (classifed as room temperature/warm, hot, or burning hot). [Ann Intern Med 2018;168:489-497]
After following up for a median of 9.2 years, there were 1,731 incident cases of oesophageal cancer.
With increasing temperature of tea preferred, the risk of developing oesophageal cancer increased (hazard ratios [HRs], 1.17, 1.30, and 1.55 for warm, hot, and burning hot tea, respectively) among men who drank tea daily compared with the reference group who drank tea less than once weekly. There
was no signifcant association between tea temperature and risk of incident oesophageal cancer in women. The association between tea temperature and oesophageal cancer risk remained when analyses were stratifed by alcohol consumption (pinteraction<0.001) or smoking status (pinteraction=0.001), with a stronger association observed in individuals with excessive alcohol intake (≥15 g/day) or currently smoking, respectively. In the analysis stratifed by alcohol consumption, excessive alcohol drinkers who also drank burning hot tea had the highest risk of oesophageal cancer compared with the reference group who had <15 g/day of alcohol and drank tea less than once weekly (HR, 5.00, 95 percent confdence interval [CI], 3.64–6.88). Similar association was observed in the analysis stratifed by smoking status, with current smokers who drank burning hot tea daily being twice as likely to develop oesophageal cancer than the reference group who were non-smokers and had tea less than once weekly (HR, 2.03, 95 percent CI, 1.55–2.67). When considering all three risk factors for oesophageal cancer concurrently, the highest risk of developing oesophageal cancer was seen in daily drinkers of burning hot tea who also smoked and consumed alcohol excessively (HR, 5.01, 95 percent CI, 4.00–6.28). However, no association was found between daily tea drinking (regardless of tea temperature) and risk of oesophageal cancer in the absence of both smoking and excessive alcohol intake. “[T]hermal injury may damage the epithelium and impair barrier function, subsequently augmenting the risk for damage from other risk factors, such as excessive alcohol consumption and smoking,” the researchers said regarding the synergistic contribution of the three risk factors on oesophageal cancer risk. [Am J Prev Med 2015;49:952-960] “Perhaps those of us who drink hot beverages often should be prudent and wait for the liquid to cool a bit frst,” suggested Drs Farin Kamangar and Neal Freedman from the Morgan State University, Baltimore, Maryland and National Cancer Institute, Bethesda, Maryland, US, respectively, in an editorial. “However, the results of this study should not cause people to abandon their favourite beverage,” they wrote, noting that tea may contain many compounds that may have benefts on health. “Most people drink their tea and coffee at a temperature that seems unlikely to cause cancer.” Recognizing tea-drinking patterns that were self-reported once at baseline as a limitation, the researchers suggested that more prospective studies be conducted to confrm the fndings.