Very hot drinks ‘probably’ cause oesophageal cancer, according to the World Health Organisation’s International Agency for Research on Cancer.
The agency issued the verdict after completing a review of over 1,000 studies on the carcinogenic properties of common hot drinks.
It concluded that drinking anything over 65°C seemed to be linked to oesophageal cancer, which can be caused by irritation of the lining of the mouth and throat.
Although the proportion of oesophageal cancer deaths caused by hot beverages is not known, it is the eighth most common cause of cancer worldwide, and one of the most deadly, accounting for five per cent of all cancer deaths.
Previous studies have shown that, in mice, water drunk at 65-70°C increased the size of oesophageal tumours.
In a statement the agency said: ‘Studies in places such as China, Iran, Turkey and South America, where tea or mate is traditionally drunk very hot (at about 70°C) found the risk of oesophageal cancer increased with the temperature at which the beverage was drunk. Drinking very hot beverages at above 65°C was classified as “probably” carcinogenic to humans.’
Christopher Wild, director of the WHO’s cancer agency, said: ‘New figures suggest drinking very hot beverages is one probable cause of oesophageal cancer and that it is the temperature, rather than the drinks themselves, that appears to be responsible.
‘Smoking and alcohol drinking are major causes of oesophageal cancer, particularly in many high-income countries.
‘However, the majority of oesophageal cancers occur in parts of Asia, South America, and East Africa, where regularly drinking very hot beverages is common and where the reasons for the high incidence of this cancer are not as well understood.’
It has been a widely held view for a long time that drinking very hot drinks can cause damage to the tissues in the throat and the oesophagus which leads to a more rapid turnover in cells which, in turn, may raise increase the likelihood of developing cancerous cells. The true level of impact is unknown and what is interesting in this case is that the conclusion is still a ‘probably’; the agency is very clear that other lifestyle factors such as smoking and drinking alcohol are far more important in causing cancer than drinking coffee.
Research score: 3/5