Drinking Very Hot Tea, Coffee May Triple Risk Of Oesophageal Cancer: Study

Drinking very hot tea and coffee may triple the risk of developing oesophageal cancer, according to the world’s largest study examining the link between hot beverages and the disease.

Cancer experts said people should allow very hot drinks to cool to a comfortable temperature before consuming them to reduce the risk.

The study found that both the temperature of hot drinks and the number of such beverages consumed were linked to a higher risk of oesophageal squamous cell carcinoma (SCC). However, hot drinks were not associated with an increased risk of adenocarcinoma (AC), the other major type of oesophageal cancer.

Temperature and frequency linked to SCC risk

“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”, according to the study published on Wednesday in the International Journal of Cancer.

Researchers also found that after accounting for drink temperature, consuming six or more hot drinks daily, compared with fewer than six, was linked to a 71% rise in SCC risk, while showing little association with AC risk.

The study was led by Dr Keren Papier, a senior nutritional epidemiologist at the University of Oxford’s population health department.

The findings were based on an analysis of hot drink consumption among nearly 980,000 people in the UK, the largest group studied globally in research on the subject so far. Participants were followed for 14 years to assess long-term patterns in their habits and health.

Findings based on people's reported preferences

Participants were asked how they preferred to drink hot beverages. The options included “very hot”, “hot”, “warm” and “do not drink hot drinks”.

The researchers based their conclusions on participants’ estimates of drink temperatures rather than precise measurements.

The study’s findings among a western European population were consistent with earlier research from Asia, Africa, South America and the Middle East. Those studies found that drinking tea or mate, a caffeinated herbal drink popular in South America, at temperatures of 70C or higher increased the risk of oesophageal cancer.

The International Agency for Research on Cancer, part of the World Health Organization, classified hot drinks in 2016 as “probably carcinogenic to humans” and “one probable cause of oesophageal cancer”.

Hot drinks are believed to increase the risk of oesophageal cancer by causing heat-related damage to cells lining the oesophagus, also known as the foodpipe. Alcohol consumption and smoking are also major risk factors for the disease.

Cooler drinks could help reduce cases

The study team said health authorities could use the findings to encourage people to consume cooler drinks and reduce the intake of very hot beverages, which could help lower the number of oesophageal cancer cases.

The researchers estimated that one in seven cases of SCC in the UK “could be avoided if individuals who reported consuming their drinks at a ‘very hot’ temperature instead consumed them at a temperature more representative of the temperature range described as ‘hot’.

They said: “The fact that we observed a clear trend in risk across self-reported temperature categories suggests that further limiting the temperature at which individuals consume their drinks to something well below average for this population may well avoid an even greater proportion of SCC cases.

“This large UK study of middle-aged adults, amongst whom hot drinks are widely consumed, provides clear evidence that temperature and frequency of hot drink consumption represent useful targets for SCC prevention.”

Fiona Osgun, head of health information at Cancer Research UK, which funded the study, said: “It’s difficult to put an exact time on how long a hot drink should be left to cool. But if you’re worried, we’d suggest just waiting until it’s comfortable to drink rather than drinking it while it’s still very hot.”

However, the charity said cafes, coffee shops and restaurants do not need to start serving tea and coffee at lower temperatures to reduce the risk of SCC.

Also Watch:

Experts flag limitation of study

Muy-Teck Teh, a professor of molecular oral oncology at Queen Mary University of London, said the study’s reliance on self-reported temperatures could have influenced the findings.

“A key limitation, however, is that perceived drink temperature is inherently subjective, and it remains unclear whether individuals who tolerate or prefer very hot drinks have altered thermosensation or mucosal sensitivity that might itself reflect underlying biological predisposition to squamous cell carcinoma and lead them to prefer hotter drinks.

“This possibility cannot be excluded and complicates interpretation of causality”, he added.