Source: www.scoop.co.nz
Author: Megan Anderson

Hot tea drinkers are being warned to slow down and cool down, after a recent study has linked drinking hot liquids to an increased risk of throat cancer. Oesophageal cancers kill more than 500,000 people per year.

The Iranian study, published in the British Medical Journal, found that drinkers of hot tea (65-69 degrees celsius) and very hot tea (over 70 degrees celsius) were more at risk of developing oesophageal cancer.

Risk of cancer was also increased with fast, hot tea drinkers, especially those who drank their tea under four minutes.

Drinking tea in under two minutes increased the risk of cancer five-fold.

The study, begun in the 1970s, investigated the Golestan province of Iran, in which cases of oesophageal squamous cell carcinoma cancer (OSCC), the most common form of throat cancer, were extremely high.

While tobacco and alcohol are known causes of OSCC and other oesophageal cancers, in the Golestan province tobacco consumption and drinking rates were low. While it is common in western countries for OSCC to occur more frequently in men than women, this pattern was absent in the province, where rates of cancer were similar for both sexes. These anomalies were detected also in Linxian, China.

Earlier studies of OSCC in Golestan had pointed to the common and widespread practice of drinking extremely hot tea as a possible cause. Drinking hot tea, without milk, is the norm throughout Iran and the Middle East.

In the Golestan region it is common for people to drink more than one litre of hot tea a day, at temperatures reaching over 60 degrees. In the UK, it is more common to drink tea 56-60 degrees. Almost all of people studied were daily tea drinkers, who drank on average around five cups a day. Researcher Dr Farhad Islami says the tea itself did not seem to be a factor in the increased risk of OSCC.

“It seems that tea drinking per se is not harmful, but the temperature of tea seems to be a strong risk factor.”

He says this suggests drinking other hot drinks may carry the same risks of developing the cancer as tea.

“Several studies have shown an association between drinking maté (a beverage which is commonly consumed in South America) and risk of oesophageal cancer. However, both the temperature and maté itself may have a role in this case.”

Dr Islami is unsure of the relationship between the years spent drinking tea and the risk of OSCC.

“Since tea drinking usually starts in early ages, studying the association between duration of tea drinking and risk of oesophageal cancer could be difficult.”

Drinking hot tea is not only a common practice overseas. It appears New Zealanders are scorching their throats through hot drinks too.

Candice Douglas, 21, a regular drinker of hot tea, says she realizes the risks of drinking hot tea quickly.

“I scald my tongue all the time because I’m too impatient and I drink my tea too quickly.”

While Doctor Brian Cox, associate professor at the University of Otago’s Dunedin School of Medicine, has yet to see the study, he stresses that the two major causes of throat and mouth cancer are alcohol and smoking.

“One study is just one study,” he warns.