The Real Issue: Temperature, Not the Tea
The central point of concern is not the coffee, tea, or any other specific drink itself, but rather its temperature. The International Agency for Research on Cancer (IARC), a part of the World Health Organization, has classified the consumption of beverages
hotter than 65 degrees Celsius (149 degrees Fahrenheit) as "probably carcinogenic to humans". This conclusion is based on studies showing a link between the habit of drinking very hot liquids and a higher incidence of oesophageal cancer, specifically oesophageal squamous cell carcinoma (SCC). The good news is that coffee and tea consumed at normal temperatures are not associated with this risk.
How Hot Is Too Hot?
The critical threshold identified by the IARC is 65°C. To put that in perspective, water boils at 100°C, and a freshly brewed black coffee or tea can easily be served at temperatures between 71°C and 85°C. Most people, however, tend to prefer drinking their beverages at a much cooler temperature, typically below 60°C, as anything above 65°C can feel uncomfortably hot or scalding. A recent large-scale study from the University of Oxford found that individuals who reported drinking their beverages "very hot" had a threefold higher risk of oesophageal SCC compared to those who drank them "warm". The simplest guide is personal comfort: if a drink is too hot to sip without wincing or causes a burning sensation, it's best to let it cool.
The Science Behind the Damage
The connection between high temperatures and increased cancer risk is rooted in the concept of chronic thermal injury. Repeatedly consuming scalding liquids can cause damage to the delicate cells lining the oesophagus, the muscular tube that carries food and drink from your throat to your stomach. This recurring injury forces the cells to repair and regenerate more frequently. Over a long period, this constant cycle of damage and repair can lead to chronic inflammation and may increase the chances of errors during cell replication, potentially leading to mutations that could eventually become cancerous. It's important to note this risk is associated with a long-term, habitual practice, not the occasional hot drink.
Who Needs to Be Most Mindful?
The risk appears to be most pronounced in individuals who habitually consume multiple very hot drinks daily. Research highlights that the combination of drinking very hot beverages with other known risk factors for oesophageal cancer, such as smoking and alcohol consumption, can significantly amplify the danger. Studies in regions like parts of Asia, South America, and East Africa, where it is traditional to drink tea or maté at very high temperatures (around 70°C), have consistently shown an elevated risk. In India, where hot tea is a cultural staple, being mindful of the temperature is particularly relevant. While one drink is unlikely to cause harm, the daily habit of consuming scalding beverages is what experts are flagging as a preventable risk factor.
Simple Adjustments for Safer Sipping
The advice from experts is not to give up your beloved chai or coffee, but simply to exercise a little patience. Allowing your drink to cool for a few minutes before you start sipping is the most effective way to lower your risk. Adding a splash of cold milk or water can also bring the temperature down to a safer level more quickly. Instead of gulping it down immediately after it's served, test the temperature with a small sip first. The goal is to find a warmth that is comforting without being scalding. This small change in your daily routine costs nothing but can contribute significantly to your long-term oesophageal health.
