By Jane Collingwood
There may be a health risk from drinking extremely hot tea, researchers report today.
The study was carried out in northern Iran, where it is common to drink large amounts of hot tea every day. Professor Reza Malekzadeh and colleagues from Tehran University, Iran, investigated a link between tea drinking habits and risk of throat cancer, or oesophageal squamous cell carcinoma.
The study was set in Golestan province, which has a high rate of this cancer. Details were taken from 300 patients and 571 similar healthy people. Almost all (98 per cent) drank black tea regularly, on average more than a litre per day. Twenty two per cent drank tea at 65 degrees Celsius or higher.
On the website of the British Medical Journal, the researchers report: “Compared with drinking lukewarm or warm tea, drinking hot tea or very hot tea was associated with an increased risk of oesophageal cancer.
“Likewise, compared with drinking tea four or more minutes after being poured, drinking tea less than three minutes after pouring was associated with a significantly increased risk.”
There was no association between the amount of tea consumed and risk of cancer.
In an editorial, Dr David Whiteman of the Queensland Institute of Medical Research, Australia, writes: “Repeated thermal injury to the oesophageal epithelium may initiate carcinogenesis, but the limited evidence to date is inconclusive.” This new study “is the most compelling test to date of the thermal injury hypothesis for oesophageal squamous cell carcinoma in humans,” he believes.
Dr Whiteman concludes that: “Allowing tea to cool for five minutes before drinking is advisable.”
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