In rural western Kenya the beverage of
In rural western Kenya, the beverage of choice is chai, the Swahili word for tea, which is a mixture of black tea MF498 and varying ratios of water and cow’s milk (typically 1:1). Given the ubiquitous consumption of chai and the high rates of esophageal cancer, we set out to study two potential risk factors of tea consumption in rural Kenya. In other endemic areas, the presence of polycyclic aromatic hydrocarbons (PAH) have been associated in beverages [12,13] and are present in the epithelium of ESCC cases . Therefore, we decided to examine the PAH content of tea leaves. Additionally, chai is consumed at hot temperatures. In this area, chai is made by first mixing the tea, water and milk together, and then bringing this mixture to a boil. This is different from other parts of the world where cold or warm milk is added to previously boiled water and tea. Sugar is also commonly added to chai. Tenwek Hospital has taken care of numerous children and adolescents with thermal esophageal injuries caused by ingestion of boiling hot chai. Anecdotally, the population seems to prefer hot drinking temperatures. But the actual preferred temperature of chai consumption has never been studied or reported in this population.
Consumption of hot food and beverages has been proposed as a risk factor for esophageal cancer in a number of different geographical locations , including drinking hot maté in South America ; drinking hot tea in Iran [17,18]; and consumption of hot food and beverages in China [19,20]. Recently, the International Agency for Research on Cancer (IARC) defined drinking temperatures above 65 °C as “very hot” and considered this exposure as probably carcinogenic (Group 2A) [21,22]. However, very limited research on this topic has been conducted in East Africa, which is known as a high-risk area for ESCC . One recent study from Tanzania has measured beverage temperature, and it found that the participants drank their beverages (mainly tea) at an average temperature of 70.6 °C, higher than that reported in previous studies from other populations . A recent case-control study by Middleton et al. in Kenya, showed an association between self-reported ingestion of hot beverages with ESCC . Historically, studies have utilized participant self-assessed questionnaires to report on their preferences for the temperature. The actual temperature of consumption is rarely reported. So, questionnaires could naturally reflect relative preferences compared to the region and not the actual temperature. Therefore, action potential is necessary to determine how questionnaires might reflect temperatures in the regional context.
Methods Consecutive healthy individuals >18 years of age who were accompanying relatives to the Tenwek Hospital endoscopy unit were recruited to participate in the study. After signing an informed consent, all subjects were given a brief questionnaire by one of two trained interviewers. Questions included demographic information (age, sex, and ethnic group), the kind of beverage most commonly consumed, how many cups of this beverage were consumed daily (a typical cup is equivalent to 300 mL), the temperature of the drink (self-reported: warm, hot, or very hot), and how many minutes the subject typically waited for the drink to cool after pouring, before drinking. Then the subject was offered a cup of chai, using methods similar to Islami et al . Briefly, when the chai was at 80 °C, two cups of tea were poured. One cup was offered to the subject, and a digital thermometer was placed in the second. The subject was then asked if he or she preferred the chai at that temperature. If not, when the chai reached 75 °C, the subject was asked again if they preferred drinking at that temperature. This was repeated at 70 °C, 65 °C, 60 °C, etc. until the preferred initial temperature at first drink was reached.