Very hot tea and coffee were linked to a threefold rise in hot drinks cancer risk for oesophageal squamous cell carcinoma. The UK study found no higher risk for adenocarcinoma. Researchers said people should let hot drinks cool until they are comfortable to drink.
University of Oxford study
Dr Keren Papier, a senior nutritional epidemiologist at the University of Oxford’s population health department, led the work published on Wednesday in the International Journal of Cancer. The analysis tracked hot drink habits in almost 980,000 people in the UK over 14 years.
Participants were asked to classify their drinks as very hot, hot, warm or do not drink hot drinks. The study’s findings were based on those self-reported categories, not on exact measured temperatures.
SCC and AC risk
The published findings state that consumption of drinks at a “very hot” versus “warm” temperature was associated with a threefold greater SCC risk but not with AC risk, after adjustment for consumption frequency. After controlling for drink temperature, daily consumption of six or more versus fewer than six hot drinks was associated with a 71% increase in SCC risk, with little association with AC risk.
The split between the two cancer types is the main practical point for readers. The association ran through SCC, while hot drinks did not heighten the risk of adenocarcinoma, the other form of oesophageal cancer.
Warm drinks and UK cases
The researchers said the risk pattern across self-reported temperature categories suggests that further limiting drink temperature could avoid more SCC cases. Their estimate is that one in seven cases of SCC in the UK could be avoided if people who report very hot drinks instead drank them at a temperature closer to the hot range.
That advice matches the study’s own conclusion: let very hot cups of tea and coffee cool before drinking. The paper also places the result alongside earlier studies in Asia, Africa, South America and the Middle East, and with the International Agency for Research on Cancer’s 2016 view that hot drinks were “probably carcinogenic to humans” and “one probable cause of oesophageal cancer.”
