Archive
2014
January
February
March
April
May
June
July
August
2013
January
February
March
April
May
June
July
August
September
October
November
December
2012
January
February
March
April
May
June
July
August
September
October
November
December
2011
January
February
March
April
May
June
July
August
September
October
November
December
2010
January
February
March
April
May
June
July
August
September
October
November
December
2009
January
February
March
April
May
June
July
August
September
October
November
December
2008
January
February
March
April
May
June
July
August
September
October
November
December
2007
January
February
March
April
May
June
July
August
September
October
November
December
2006
March
April
May
June
July
August
September
October
November
December
Mar. 28, 2009

Tea's Great, Just Don't Drink It When It's Too Hot

by Science Friday Education

By Nikki Saint Bautista

Two things that you will find in every culture are tea and alcoholic beverages, but drinking plenty of tea has been known to reduce cancer, whereas the opposite is true for alcohol. Water was purified for consumption either by boiling it or fermenting the juice from squeezed fruits. However, the British Medical Journal published a study yesterday, which claims that drinking scalding hot (70° Celsius or 150° Fahrenheit) liquids may lead to a higher risk in esophageal cancer.

Epidemiologist Nick Day, who was one of the first leaders on this project, explained that cancer of the esophagus starts out with a lump inside the esophagus and over time the area becomes so irritated that it becomes difficult to swallow.

The search for the explanation of why there was a 20-25% chance of developing esophageal cancer in certain regions of Iran began in the 1970s, but the “Iranian Revolution halted the study for several years,” according to the companion video to the BMJ report.

Reza Malekzadeh, vice president for research at Iranian Academy of Medical Sciences, stated that Iran’s socioeconomic situation improved after the Iranian Revolution and in 2004, studies resumed.

Nearly 50,000 people were involved in this study, which spanned several decades, and thousands of people in Iran and around the world may be saved as a result of finding the correlation between hot tea and cancer.

In the west esophageal cancer is strongly linked to smoking and drinking, whereas tobacco, opium, or alcohol are not consumed so much in Gollestan-- an “arid location” and “the worst affected area,” says BMJ video reporter.

BMJ VIdeo

Other causes may be related to “diets deficient in fruits and vegetables because the land is not fertile,” states Paul Brennan of the International Agency for Research on Cancer.

The BBC’s article following the BMJ report stated, “The University of Tehran researchers studied tea drinking habits among 300 people diagnosed with OSCC and compared them with a group of 570 people from the same area. Nearly all participants drank black tea regularly, on average drinking over a litre a day.”

Gollasten is a dry region where the population does not drink or smoke much, but the people do consume plenty of tea throughout the day, often without letting it cool even for a minute.

"Hot tea was drunk to quench the thirst, and drunk very hot, and drunk in very large quantities," said Nick Day, who is now Emeritus Professor of Epidemiology at Cambridge. The distinction he made between tea and coffee drinking habits in the western world versus that of Iran's is this: westerners sip hot beverages for pleasure, while tea is pretty much all that's there.

"Tea is innocent by itself, most likely, but it is really the temperature which drives the risk because it damages the esophageal mucosa and leads to other changes, which may be due to opium, tobacco, or poor diet," explained Paolo Boffetta, en epidemiologist and research group head for IARC in Lyon, France.

The What's Cooking America website lists the varying temperatures of water with its cooking terminology. Water boils at 212°F (sea level), and simmers at 190°F. Water in the state before simmering and boiling is said to be “tepid” when it is between 85° to 105°F (comparable to our body temperature of 98.6°F); “warm” and touchable in between 115° to 120°F; “hot” when it is 130°F to 135°F (one may be injured upon touching water in this temperature range); “poach” is when the water shivers at the 160°to 180°F range.

Starbucks serves their hot tea at 200°F and their lattes are served hot in the range of 130° to 150°F and from 160° to 180°F when a customer requests their drink to be “extra hot.”

The BBC summary of the BMJ report concluded, “Compared with drinking warm or lukewarm tea (148°F and less), drinking hot tea (149° to 156.2°F) was associated with twice the risk of esophageal cancer, and drinking very hot tea (158°F or more) was associated with an eight-fold increased risk.”

According to Nick Day and Paul Brennan, there is an "international significance" to the study as well. Brennan claims, "We can all be very proud and happy with is that a very strong level of international collaboration has been shown in bringing the results to this level."

According to Cha-An, a Japanese Tea House on East 9th St, tea should be served at 175℉ but it's worth waiting for your cup to cool down before you take that first sip.

About Science Friday Education

The views expressed are those of the author and are not necessarily those of Science Friday.

Science Friday® is produced by the Science Friday Initiative, a 501(c)(3) nonprofit organization.

Science Friday® and SciFri® are registered service marks of Science Friday, Inc. Site design by Pentagram; engineering by Mediapolis.

 

topics