The Global Consensus on 'Very Hot' Drinks
For years, the conversation around beverages and health focused on what was in the cup—caffeine, antioxidants, or sugar. However, a landmark evaluation shifted the focus to the thermometer. The International Agency for Research on Cancer (IARC), a part
of the World Health Organization (WHO), classified drinking beverages at temperatures above 65°C (149°F) as “probably carcinogenic to humans”. This conclusion was based on a review of numerous studies, which found a consistent link between the consumption of very hot drinks and an increased risk of esophageal cancer. It is important to note that this classification places the thermal aspect in the same risk category as things like red meat consumption, indicating a probable, but not definite, link. The key takeaway was clear: the danger isn't in the coffee or tea itself, but in the scalding heat.
How Heat Harms the Esophagus
The esophagus is the muscular tube that carries food and liquid from your throat to your stomach. Its lining is delicate and not designed to handle repeated exposure to extreme temperatures. When you consistently drink liquids above 65°C, you can cause what is known as thermal injury. This repeated scalding can lead to chronic inflammation of the cells lining the esophagus. Over time, this constant state of injury and repair can increase the chances of cellular mutations, which may eventually lead to the development of esophageal squamous cell carcinoma, a common form of esophageal cancer. Endoscopic examinations of individuals who regularly consume very hot liquids have shown visible damage, including inflammation and the formation of a whitish pseudomembrane, which resolves when the habit is stopped.
Putting the Risk into Perspective
While the link is concerning, it is crucial to avoid alarmism. Regularly drinking very hot beverages doesn't guarantee you will develop cancer; it is a contributing risk factor. The risk is most pronounced in populations where drinking extremely hot tea or other infusions is a deep-rooted cultural norm. For example, a large-scale study in Iran, a region with high rates of this cancer, found that individuals drinking 700 ml of tea daily at 60°C or higher had a 90% increased risk compared to those drinking at cooler temperatures. Similarly, a recent University of Oxford study found that those who prefer their drinks 'very hot' could have up to a threefold greater risk. This risk can also be amplified when combined with other major risk factors for esophageal cancer, such as smoking and alcohol consumption.
Your Action Plan for Safer Sipping
The good news is that this risk is almost entirely preventable with a minor change in habit. The solution is simple: patience. Instead of drinking your tea or coffee immediately after it's poured, allow it to cool for a few minutes. Experts suggest that waiting just four or five minutes can bring a scalding drink down to a safer temperature, below 65°C. A practical way to test this is the 'sip test'—if you have to sip gingerly because it's too hot to gulp, it's a sign to wait a little longer. Another simple trick, especially for tea and black coffee lovers in India, is to add a small amount of cool water or milk, which instantly lowers the overall temperature. The ideal drinking temperature for both safety and flavour is often cited as being around 60°C or slightly below.
It’s Not the Chai, It’s the Heat
It's worth repeating that the research does not condemn tea or coffee. In fact, after reviewing over 1,000 studies, the IARC found inadequate evidence that coffee itself is carcinogenic and noted that it may even reduce the risk of certain cancers, like those of the liver and uterine endometrium. Tea is also celebrated for its health benefits, including a wealth of antioxidants. The problem is exclusively the high temperature. So, there is no need to give up your beloved masala chai, filter coffee, or green tea. By simply adopting the habit of letting your beverage cool to a warm, comfortable temperature, you can continue to enjoy the ritual and the flavour without the associated long-term health risk. It’s a small adjustment that your esophagus will thank you for in the years to come.
