Drinks above 65°C linked to increased oesophageal cancer risk

Drinking beverages at extreme temperatures may significantly increase the risk of developing oesophageal cancer. The International Agency for Research on Cancer (IARC), a branch of the World Health Organization, has classified the consumption of very hot drinks as 'probably carcinogenic to humans,' placing them in Group 2A.

According to the IARC, beverages consumed at temperatures exceeding 65°C are the primary concern. The risk is not tied to the specific ingredients of the drink—such as the chemical composition of coffee or tea—but rather to the physical temperature of the liquid. This heat causes direct thermal damage to the cells lining the oesophagus, which can lead to the development of squamous cell carcinoma (SCC).

The scale of the risk

Recent data highlights the severity of this link. A large-scale study in the UK involving approximately 980,000 adults found that individuals who prefer their drinks 'very hot' are three times more likely to develop oesophageal cancer than those who consume tepid beverages. Furthermore, the frequency of consumption plays a role, as drinking six or more hot beverages per day further increases the risk.

These results suggest that the temperature, rather than the drinks themselves, is the responsible factor in these cancer cases, shifting the focus from chemical properties to physical thermal stress.

Global context and causes

Oesophageal cancer currently ranks as the eighth most common cause of cancer globally. While smoking and alcohol consumption are the primary drivers of the disease in high-income nations, different patterns emerge in other regions. High incidence rates in parts of East Africa, South America, and Asia are closely linked to cultural practices where beverages like maté and tea are traditionally served at very high temperatures, often reaching around 70°C.

Why this shift matters

This classification represents a significant shift in medical understanding. For years, researchers suspected the chemical properties of coffee might be carcinogenic; however, the evidence now points toward the physical act of consuming hot liquids.

This finding provides a simple, actionable preventative measure for the public. By allowing beverages to cool before drinking or adding milk to lower the temperature, consumers can reduce the risk of thermal injury to their oesophageal lining. This is particularly critical for heavy consumers of hot drinks who may be unknowingly exposing themselves to chronic thermal stress.

What to watch

While the link between temperature and squamous cell carcinoma is established, health officials continue to monitor the long-term impact of beverage consumption habits across different demographics. The focus remains on public education regarding safe drinking temperatures to lower the global burden of this specific cancer type.