The Science of 'Too Hot'
The conversation around hot drinks and health isn't new, but the focus has shifted. For years, researchers investigated specific beverages like coffee or maté for potential risks. However, a landmark 2016 report from the World Health Organization's International
Agency for Research on Cancer (IARC) clarified the concern: it's not about the drink, but its temperature. The IARC classified drinking beverages hotter than 65°C (149°F) as "probably carcinogenic to humans". This conclusion was based on studies from regions in Asia, South America, and Africa where drinks are traditionally consumed very hot, often above 70°C (158°F). These studies found a consistent link between the practice and a higher risk of oesophageal squamous cell carcinoma, a specific type of cancer affecting the food pipe.
How Heat Harms the Oesophagus
The oesophagus is a muscular tube connecting your throat to your stomach, and its lining is made of delicate tissue. When you repeatedly swallow scalding hot liquids, you cause what's known as "thermal injury". Think of it like a recurring burn. This constant damage forces your body into a cycle of repair. Over many years, this process of chronic injury and cell regeneration can increase the chances of cellular errors and mutations, which may eventually lead to cancer. Endoscopic examinations of people who have ingested excessively hot food or drink reveal visible damage, including inflammation, ulcers, and a distinct pattern sometimes called a "candy-cane oesophagus" due to the alternating red and white bands of injured tissue.
Finding the 'Goldilocks Zone'
So, how hot is too hot? The 65°C (149°F) threshold identified by the IARC is the key benchmark. For context, coffee is often brewed between 90°C and 96°C and served in cafes at temperatures as high as 85°C. One recent, large-scale study in the UK involving nearly a million people reinforced these concerns. It found that individuals who described their drinks as "very hot" had a threefold higher risk of oesophageal squamous cell carcinoma compared to those who preferred them "warm". The risk also increased with the quantity of hot drinks consumed daily. While the study relied on self-reported temperatures, the findings strongly suggest that consistently drinking beverages at scalding temperatures is a preventable risk factor.
Simple Steps for Safer Sipping
The good news is that you don't need to abandon your cherished morning ritual. The solution is simple and practical: let your drink cool down. Experts suggest an optimal drinking temperature is actually below 60°C (140°F), a range where you can better appreciate the flavour without the risk of scalding. Here are a few easy habits to adopt: Wait a few minutes after pouring before you take your first sip. If you get your beverage from a cafe, take the lid off to accelerate cooling. Add a splash of cold milk or water to instantly lower the temperature. Finally, listen to your body; if a drink feels uncomfortably hot in your mouth, it is certainly too hot for your oesophagus. By making this small adjustment, you can continue to enjoy the comfort of your favourite beverage while safeguarding your long-term health.
