Increased oesophagus cancer risk with hot tea or coffee
The World Health Organisation (WHO) International Agency For Research has classified drinking “very hot” beverages – above 65 ° C, such as hot tea or coffee – as “probably carcinogenic” to humans. A recent study has suggested that hot tea drinkers risk oesophageal squamous cell carcinoma compared to those who drank cooler and less tea in general.
Researchers have collected data over some 10 years on 50,000 adults in northeastern Iran, where high rates of oesophageal cancer have been reported and where residents drink an average of 1,100ml of black tea daily: participants were asked about their preferences for tea temperature, and how soon they drank the tea after pouring it. By 2017, 317 participants had developed oesophageal squamous cell carcinoma.
Participants who regularly drank tea at high temperature were 41% more likely to develop oesophageal cancer, and those who drank their tea within two minutes of pouring it had 51% higher risk than those who waited six minutes or more.Overall, participants who drank at least 700ml daily at temperatures above 60 ° C were observed to have 91% higher risk than those who drank less tea, at lower temperatures.
Even after accounting for other factors that could affect the risk, including use of tobacco, alcohol or opium, and socio-demographic factors, the heightened risk with scalding-hot tea remained – likely because of the direct influence on throat tissues through consistent inflammation.
Study leader Dr Farhad Islami of the American Cancer Society (ACS) in Atlanta, Georgia has admitted that drinking hot tea is a very common habit worldwide, but recommends waiting a while until hot beverages cool down before drinking.
Dr Dirk Lachenmeier, a food chemist and toxicologist in Karlsruhe, Germany, has noted that this study is more well-designed and informative, while most previous studies were based on self-reports.
Very high preparation temperatures may affect taste, so new studies are also investigating serving temperatures in restaurants and cooling behaviours, such as using milk.
Category: Features, Health alert