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Hot Tea Consumption Linked to Higher Risk for Esophageal Cancer

  • Authors: News Author: Laurie Barclay, MD
    CME Author: Désirée Lie, MD, MSEd
  • CME Released: 4/3/2009
  • Valid for credit through: 4/3/2010, 11:59 PM EST
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Target Audience and Goal Statement

This article is intended for primary care clinicians, gastroenterologists, oncologists, and other specialists who care for patients at risk for esophageal cancer.

The goal of this activity is to provide medical news to primary care clinicians and other healthcare professionals in order to enhance patient care.

Upon completion of this activity, participants will be able to:

  1. Describe the association between temperature of tea consumed and risk for esophageal squamous cell carcinoma.
  2. Describe the association between waiting time to consume hot tea and risk for esophageal squamous cell carcinoma.


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  • Laurie Barclay, MD

    Laurie Barclay, MD, is a freelance writer and reviewer for Medscape.


    Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.


  • Brande Nicole Martin

    Brande Nicole Martin, is the News CME editor for Medscape Medical News.


    Disclosure: Brande Nicole Martin has disclosed no relevant financial information.

CME Author(s)

  • Désirée Lie, MD, MSEd

    Clinical Professor, Family Medicine, University of California, Orange; Director, Division of Faculty Development, UCI Medical Center, Orange, California


    Disclosure: Désirée Lie, MD, MSEd, has disclosed no relevant financial relationships.

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Hot Tea Consumption Linked to Higher Risk for Esophageal Cancer

Authors: News Author: Laurie Barclay, MD CME Author: Désirée Lie, MD, MSEdFaculty and Disclosures

CME Released: 4/3/2009

Valid for credit through: 4/3/2010, 11:59 PM EST


April 3, 2009 — Drinking hot tea was strongly associated with a higher risk for esophageal cancer according to the results of a northern Iranian population-based case-control study reported online first on March 27 in the British Medical Journal.

"An association between drinking hot beverages and risk of oesophageal cancer has been reported in several studies from different parts of the world," write Farhad Islami, MD, from Shariati Hospital, Tehran University of Medical Sciences in Iran, and colleagues. "In Golestan, tea and water are the only drinks commonly consumed, with comparable average intake. An ecological study showed that inhabitants of Golestan drank more tea and at a higher temperature than people living in a nearby area with a low incidence of oesophageal cancer."

The goal of this study was to evaluate the relationship between characteristics of tea drinking habits in Golestan province in northern Iran, which is an area with a high incidence of esophageal squamous cell carcinoma (SCC), and risk for that disease. Patterns of tea drinking and temperature at which tea was usually drunk were also determined for healthy persons enrolled in a cohort study.

Tea drinking among 300 patients with histologically proven esophageal SCC was compared with that in 571 matched neighborhood controls in the case-control study and in 48,582 participants in the cohort study. The primary study endpoint was the odds ratio (OR) of esophageal SCC associated with drinking hot tea.

Regular drinking of black tea was reported by 98% of the cohort participants, with mean daily volume more than 1 L. Reported temperature of tea was less than 60°C in 39.0% of participants, 60°C to 64°C in 38.9%, and 65°C or higher in 22.0%. Reported temperature agreed moderately with actual temperature measurements (weighted κ, 0.49).

In the case-control study, risk for esophageal cancer was increased for drinking hot tea (OR, 2.07; 95% confidence interval [CI], 1.28 – 3.35) or very hot tea (OR, 8.16; 95% CI, 3.93 – 16.9) vs lukewarm or warm tea. Risk was also significantly increased for drinking tea 2 to 3 minutes after pouring (OR, 2.49; 95% CI, 1.62 – 3.83) or less than 2 minutes after pouring (OR, 5.41; 95% CI, 2.63 – 11.1) vs drinking tea at least 4 minutes after being poured. Responses to the questions about temperature at which tea was drunk agreed strongly with interval from tea being poured to being drunk (weighted κ, 0.68).

"Drinking hot tea, a habit common in Golestan province, was strongly associated with a higher risk of oesophageal cancer," the study authors write.

Limitations of this study include possible information bias regarding the amount and temperature of consumed tea, validation study performed among healthy people, possible selection bias, and some missing data.

"A large proportion of Golestan inhabitants drink hot tea, so this habit may account for a substantial proportion of the cases of oesophageal cancer in this population," the study authors write. "Informing the population about the hazards of drinking hot tea may be helpful in reducing the incidence of oesophageal cancer in Golestan and in other high risk populations where similar habits are prevalent."

In an accompanying editorial, David C, Whiteman, from Queensland Institute of Medical Research at Royal Brisbane Hospital in Australia, recommends allowing tea to cool for 5 minutes before drinking.

"The mechanism through which heat promotes the development of tumours warrants further exploration and might be given renewed impetus on the basis of these findings," Dr. Whiteman writes. "These findings are not cause for alarm, however, and they should not reduce public enthusiasm for the time honoured ritual of drinking tea. Rather, we should follow the advice … [that suggests] a five to 10 minute interval between making and pouring tea, by which time the tea will be sufficiently flavoursome and unlikely to cause thermal injury."

The Digestive Disease Research Center of Tehran University of Medical Sciences, the National Cancer Institute, National Institutes of Health, and the International Agency for Research on Cancer supported this study. The study authors and Dr. Whiteman have disclosed no relevant financial relationships.

BMJ. Published online March 27, 2009.

Clinical Context

SCC of the esophagus is the most common type of esophageal cancer worldwide; in the West, it is associated primarily with smoking and alcohol consumption, with a higher incidence in men than women. However, in certain regions such as northern Iran and Linxian, China, with very high incidence of SCC of the esophagus, the consumption of hot tea has been linked to increased risk for esophageal SCC. The mechanism of carcinogenesis is believed to be thermal damage of the epithelium.

The study was a combination of a case-control and a cohort study to examine the association between the temperature at which tea was consumed and waiting time between making and drinking hot tea and to examine the link between consumption of hot tea and risk for esophageal SCC.

Study Highlights

  • In the case-control study, 300 patients with histologically proven esophageal SCC were matched to 571 control patients between 2003 and 2007 in Golestan province, northern Iran.
  • Patients with esophageal SCC presented to the only referral center for esophageal SCC; all patients underwent video esophagogastroduodenoscopy with fixed biopsy samples examined by experienced pathologists.
  • Only newly diagnosed patients with esophageal SCC were included; population-based control patients were matched for age, region, and sex.
  • Participants were interviewed on the same day they underwent diagnostic endoscopy by trained nutritionists, and data on demographics and tea drinking were collected.
  • They were asked whether they drank tea and if so whether they drank it very hot, hot, warm, or lukewarm.
  • There were also questions about the interval between tea being poured and drunk and consumption of black vs green tea.
  • The Golestan Cohort Study was a prospective study of 50,045 adults aged 45 to 75 years that included 10,032 participants from urban and 40,013 participants from rural areas.
  • Participants were asked the same questions about the temperature of tea drunk and the minutes of waiting between pouring and drinking of hot tea.
  • In addition, cohort members had a cup of hot tea prepared, the temperature was measured at 5ºC intervals, and they were asked at intervals as the temperature decreased which was the temperature they most likely drank tea.
  • For the case-control study, mean age was 64.4 years, half were men, 73% were from rural areas, 14% used tobacco, 6% to 10% used opium, and 13% to 20% used both.
  • All but 1 patient with esophageal SCC drank hot tea.
  • Tea temperature was significantly associated with risk for esophageal SCC.
  • Compared with drinking warm or lukewarm tea, the OR for hot tea was 2.07; for very hot tea, it was 8.16 (P for trend < .001).
  • The interval between tea being poured and drunk was inversely associated with risk for esophageal SCC, with OR of 2.49 for 2 to 3 minutes and 5.41 for less than 2 minutes compared with 4 or more minutes (P for trend < .001).
  • No clear pattern was seen between amount of black tea consumed and risk for SCC.
  • There was no significant association between green tea consumption and risk for esophageal SCC.
  • For the cohort, data were available for 48,582 participants, of whom 96.8% drank black tea every day for a mean of 1179 mL daily.
  • Only 5.8% of the participants drank green tea.
  • 39% drank their tea at temperatures less than 60°F, 39% at 60°F to 64°F, and 22% at 65°F or higher.
  • Moderate agreement was found between reported tea drinking temperature and actual temperature measurements.
  • The authors concluded that in a region with high tea consumption with a high incidence of esophageal SCC, higher temperature of the tea consumed was a risk factor for esophageal SCC.

Pearls for Practice

  • Higher temperature of hot tea consumed is associated with greater risk for esophageal SCC among northern Iran's inhabitants.
  • A longer waiting time between tea being prepared and consumed is associated with lower risk for esophageal SCC in northern Iran.