What the Global Experts Say
The conversation around hot drinks and health gained significant attention when the World Health Organization's International Agency for Research on Cancer (IARC) evaluated the evidence. After a thorough review, the agency classified drinking beverages
at temperatures above 65°C (149°F) as “probably carcinogenic to humans”. The key finding is that the risk isn't tied to coffee or tea themselves, but rather the temperature at which they are consumed. The primary concern is an increased risk for cancer of the oesophagus, the tube that carries food from your throat to your stomach. The theory is that repeated thermal injury from scalding liquids can damage the cells lining the oesophagus, potentially leading to harmful changes over time.
Putting 65°C into Perspective
The number 65°C might seem abstract, so what does it actually feel like? For context, water boils at 100°C. Many commercial coffee shops serve their beverages at temperatures between 71°C and 85°C, well above the IARC's threshold of concern. However, the preferred drinking temperature for most people is actually lower. Studies and consumer surveys suggest that many people find coffee most enjoyable between 55°C and 70°C. A simple rule of thumb is that if a drink is hot enough to scald your mouth or tongue on the first sip, it's likely too hot. Waiting just a few minutes after a drink is poured can significantly lower its temperature. For instance, letting a freshly brewed tea sit for four or more minutes can make a substantial difference. One study even found letting a drink cool for five minutes can lower the temperature by 10-15°C.
Understanding the Nuances of Risk
It’s important not to be alarmist. The IARC's “probably carcinogenic” (Group 2A) classification means there is strong evidence, but it's not as definitive as for substances in Group 1 (like tobacco). The risk is associated with the consistent, long-term habit of drinking very hot liquids, not the occasional cup that's a bit too steamy. Most of the studies observing this link were conducted in parts of Asia, South America, and the Middle East, where it's traditional to consume beverages like tea or maté at very high temperatures, often around 70°C. Furthermore, other major risk factors for oesophageal cancer, especially in high-income countries, include smoking and alcohol consumption. Some research suggests the risk from hot drinks is more pronounced when combined with these other habits.
The Indian Context: A Nation of Chai Lovers
In India, the culture of drinking piping hot chai from roadside stalls or freshly brewed filter coffee at home is deeply ingrained. These beverages are often served at temperatures that could easily exceed the 65°C guideline. While specific data on average serving temperatures in India is sparse, the cultural preference for 'kadak' or 'garam' chai suggests that many are likely consuming their drinks in the higher temperature range. The findings are therefore particularly relevant. It prompts a moment of reflection on a daily ritual that is central to social and cultural life across the country. The good news is that enjoying this tradition more safely doesn't require giving it up, but rather making a small adjustment.
Simple Tips for Safer Sipping
Protecting yourself from this potential risk is straightforward and doesn't mean you have to drink your beverages lukewarm. The easiest and most effective strategy is simply to wait. Instead of sipping your tea or coffee immediately after it's poured, let it cool for a few minutes. Experts suggest that letting a drink rest until it is warm rather than scalding is sufficient. Adding a small amount of cold milk or water can also quickly bring the temperature down to a safer level. Pay attention to your body's signals; if a drink feels uncomfortably hot on your lips or tongue, it's a clear sign to wait a little longer before you continue.
