A comprehensive review of epidemiological studies has found strong evidence that regularly consuming very hot beverages and foods increases the risk of esophageal cancer (EC), reinforcing long-standing concerns about thermal injury to the esophagus.
Researchers examined decades of studies on tea, coffee, mate (a traditional South American herbal drink), and other hot foods and beverages. While the amount of coffee or tea consumed showed little consistent association with esophageal cancer risk, temperature emerged as a key factor. Most studies reported a statistically significant increase in EC risk among people who drank these beverages at higher temperatures.
Mate showed the clearest pattern. Although fewer studies were available, they consistently demonstrated that both the quantity consumed and the temperature at which it was drunk independently increased esophageal cancer risk.
More than half of studies examining other hot foods and drinks also found significantly higher EC risks linked to hotter consumption.
Biological Plausibility Strengthened
The idea that repeated thermal injury may damage the esophageal lining dates back nearly a century. In 1939, physician W.L. Watson described thermal irritation as “probably the most constant factor” predisposing individuals to esophageal cancer.
Concerns that hot drinks cool too quickly to harm the esophagus were challenged by experimental evidence. Studies measuring intra-esophageal temperature showed that drinking beverages at around 65 °C can raise esophageal temperature by 6–12 °C, depending on sip size—enough to plausibly cause tissue injury.
Chemicals vs. Heat
Tea, coffee, and mate contain numerous bioactive compounds, some of which have shown mutagenic effects in laboratory studies, while others appear to have cancer-preventive properties in animal models. Overall, epidemiological evidence suggests these chemical effects do not explain esophageal cancer risk as clearly as heat exposure does.
Global Health Implications
The findings are particularly relevant in regions where drinking very hot tea, coffee, maté, or consuming hot foods is customary. If confirmed, high-temperature consumption could account for a substantial proportion of esophageal cancer cases in these populations.
