Saturday, April 4, 2009
Drinking hot tea?
There is something about a hot cup of frothing tea or teh tarik to soothe a tired soul. Wait at least four minutes before drinking hot tea, is the advice from researchers who have found drinking very hot tea can increase the risk of throat cancer.
Cancer of the oesophagus has causal links to smoking and alcohol consumption, but previous studies have suggested hot drinks may also be a risk factor.
An international team of researchers, reporting in the British Medical Journal, examined the theory that repeated thermal injury to the oesophagus might initiate cancer. They studied a population in northern Iran, which has one of the highest rates for oesophageal cancer in the world, yet consumes very little alcohol or tobacco.
The researchers found people who drank their tea within two minutes had a five times higher risk of oesophageal cancer compared with those who waited more than four minutes before drinking their tea. Queensland Institute of Medical Research senior research fellow David Whiteman said the study was the most compelling test to date of the thermal injury hypothesis.
''It's interesting for us to be aware of, because it gives us an insight potentially into other ways in which cancers might arise,'' Dr Whiteman said. We know about smoking and alcohol being causes for these cancers. But this idea that chronic irritation from hot things in the oesophagus might also lead to cancer has long been suspected. The research team led by Tehran University of Medical Sciences, Farhad Islami, studied 300 people with oesophageal cancer and compared their tea drinking preferences with a control group of more than 500. Almost all participants drank one litre of tea a day.
They found the cancer patients were eight times more likely to drink their tea very hot or more than 70 degrees, compared with the control participants. The findings were similar for how quickly they drank the tea- people who drank their tea within two minutes had a five times higher risk than those who waited more than four minutes.
The researcher reported there was no significant association between the risk cancer and the amount of tea consumed.
By Nyssa Skilton, The Canberra Times