Piping Hot Milky Tea In The Tanzanian Oesophageal Cancer Hotspot: A Cross-Sectional Study


1 International Agency for research on cancer
2 kilimanjaro christian medical centre

OBJECTIVE. Esophageal cancer is a devastating disease with poor prognosis. In East Africa, it ranks amongst the top 4 most common cancers and its histology is mainly oesophageal squamous cell cancer (ESCC). Causal factors in this area are not well identified. As hot beverage drinking has been strongly linked with ESCC in the high risk area of Iran, we measured population-level hot beverage drinking habits in the oesophageal cancer hotspot of North Tanzania.
METHODS. We conducted a cross-sectional study of established and putative ESCC risk factors in 188 participants from the general-population in Kilimanjaro, North Tanzania. Temperature of and time taken to drink tea were measured. A questionnaire on regular tea habits was also administered. We examined these measurements in relation to external international means and to tea type (“milky tea”= up to 50% milk and water boiled together; “black tea”=no milk at all) and socio-demographic factors. 
​RESULTS. In tea preparation, 62% of participants added milk before boiling.  Participants started drinking tea at a mean of 70.6°C (standard deviation 3.9), which was higher than in all previous studies worldwide (p≤0.01), in particular it was much higher than in Golestan, Iran. The strongest determinant of tea drinking temperature was the type of tea. Milky tea (milk and water boiled together) was drunk 3.2°C (95% confidence interval: 2.1, 4.3) hotter than black tea. Men drank their tea hotter and faster than women. The prevalence of reported tongue burning was high and agreed with measured tea temperatures.
CONCLUSION. Repeated thermal injury to the esophageal mucosa may be implicated in carcinogenesis, by damagining the mucosa repair mechanism. Akin to the deeper dermatological scald burns caused by hot milk than by hot water, piping hot milky tea drinking may be a significant risk factor for EC in this area.