Africa's oesophageal cancer corridor: Do hot beverages contribute?

Abstract

Hot beverage consumption has been linked to oesophageal squamous cell cancer (EC), but its contribution to the poorly understood East African EC corridor is not known. In a cross-sectional study of general-population residents in Kilimanjaro, North Tanzania, tea drinking temperatures and times were measured. Using linear regression models, we compared drinking temperatures to those in previous studies, by socio-demographic factors and tea type ("milky tea" which can be 50 % or more milk and water boiled together vs "black tea" which has no milk). Participants started drinking at a mean of 70.6 °C (standard deviation 3.9, n = 188), which exceeds that in all previous studies (p ≤ 0.01 for each). Tea type, gender and age were associated with drinking temperatures. After mutual adjustment for each other, milky tea drinkers drank their tea 1.9 °C (95 % confidence interval: 0.9, 2.9) hotter than drinkers of black tea, largely because black tea cooled twice as fast as milky tea. Men commenced drinking tea 0.9 °C (-0.2, 2.1) hotter than women did and finished their cups 30 (-9, 69) seconds faster. 70 % and 39 % of milky and black tea drinkers, respectively, reported a history of tongue burning. Hot tea consumption, especially milky tea, may be an important and modifiable risk factor for EC in Tanzania. The contribution of this habit to EC risk needs to be evaluated in this setting, jointly with that of the many risk factors acting synergistically in this multi-factorial disease.