Man consumes water and water based drinks to meet the demand from the body for maintaining homeostatic balance. Some are consumed cold, some at ambient temperature and others in hot or warm state. While cool drinks are more popular during summer, warm/hot drinks are preferred in winter or rainy days. Juices, beverages, soft drinks, buttermilk, sweetened yogurts and flavored milk are consumed at 4-10C while tea, coffee, milk, cocoa, malted drinks, etc are enjoyed better when taken hot. In a startling report a group of scientists have raised an alarm regarding taking beverages like tea at high temperatures beyond 70 degree Celsius (158 F). According to them, drinking hot tea poses risk of oesophagus cancer and recommends waiting for 10 minutes after the preparation before drinking. Oesophagus is the tube that carries food from the throat to the stomach and is susceptible to cancer due to many reasons, most common being drinking of alcohol and use of tobacco, causing more than half a million deaths a year in the world. The vulnerability to this type of cancer increases several fold if the socio-economic conditions are poor, consumption of fruits and vegetables is not practiced and irregular habits of brushing the teeth. But no link has so far been established between the temperature of the food consumed and oesophagus cancer. The new findings implicating hot black tea in cancer raises disturbing questions regarding the eating and drinking practices and their impact on health.
According to the above findings drinking black tea hot was associated with twice the risk of oesophagus cancer while drinking very hot tea raised the risk level eight-fold. Likewise drinking tea within 2 minutes after preparing raised the risk five-fold as compared to drinking the same tea after 4 minutes. Conventionally any beverage at a temperature of less than 149 F is considered warm, at 158 F as hot and beyond 158 F as very hot. It is hard to believe that temperature of the drink can make such a difference considering the in-built safety provided by the inability of the oral cavity to tolerate high temperatures. Many consume tea at a much lesser temperatures and this is especially true with green tea and black tea beverages which are prepared by dropping the tea leaves into hot water followed by straining. In some cases tea is 'cooked' in boiling water for a few minutes, strained and consumed with or without sugar. More over sipping action and roiling the liquid in the mouth for some time before gulping naturally will bring down the temperature significantly. Also to be remembered is that drinking coffee or tea is never done in a jiffy as it provides relaxation when one sits own for the drink and the slow process of sipping does not permit the drinking temperature to go high beyond the danger level at any time. It is doubtful whether in all these cases the temperature would go beyond 149 F when the drink passes down the throat. Same applies to coffee also. Whitened tea or coffee is still more safe as addition of milk naturally brings down the temperature to tolerable levels.
The alarm was raised by the scientists based on their finding of wide spread incidence of oesophagus cancer in Golestan Province in Iran where local people traditionally drink very hot tea to which their oral cavity is accustomed. But it is rather naive to assume that hot tea is the only factor that is responsible because the population there are also reported to be socio-economically poor; they do not eat vegetables at all and do not brush their teeth regularly. Probably further studies only can bring out the causative factors that make this cancer prevalent in that region. Such stray reports should not dissuade people drinking coffee and tea regularly to shun their enjoyable habit fearing dangerous consequences. At best one can consider exercising caution while drinking hot beverages in general, to be on the safer side!