Study Links Very Hot Tea and Coffee to Higher Esophageal Cancer Risk
Drinking tea or coffee at “very hot” temperatures is associated with a 3.17-fold increase in the risk of developing esophageal squamous cell carcinoma (SCC), according to a large-scale study of nearly 980,000 British adults. The research, published in the International Journal of Cancer, suggests that thermal injury to the esophagus may impair mucosal integrity and promote carcinogenic processes.
- Individuals preferring “very hot” beverages face over triple the risk of esophageal SCC compared to those who drink beverages “warm.”
- High consumption volume (six or more drinks daily) is linked to a 71% increase in SCC risk, independent of temperature.
- The risk is specific to squamous cell carcinoma; no similar association was found for esophageal adenocarcinoma.
The study, led by nutritional epidemiologist Keren Papier of the University of Oxford, analyzed data from the Million Women Study and the UK Biobank. This represents the largest investigation to date into the link between beverage temperature and esophageal cancer. While previous research focused on extremely high temperatures—such as the 70°C (158°F) typically associated with mate consumption in South America—this analysis examined the temperature preferences common in Western populations.
Thermal Injury and the Pathogenesis of Esophageal SCC
The researchers posit that the primary driver of this increased risk is not the chemical composition of the tea or coffee, but the physical temperature of the liquid. The study found that adding milk did not significantly alter the identified risks, suggesting that the heat itself causes the damage. Biologically, repeated exposure to high temperatures can lead to esophageal necrosis and the formation of premalignant lesions.
“The most likely mechanism is thermal injury, which may impair mucosal integrity and promote carcinogenic processes,” the study authors wrote in the International Journal of Cancer.
This mechanism mirrors the effect of repeated burns on other parts of the body. Aaron Sasson, chief of surgical oncology and co-director of the gastrointestinal oncology team at Stony Brook Cancer Center, noted to Fox News that this process of repeated cellular damage can create an environment conducive to cancer development. For those experiencing chronic gastrointestinal discomfort or suspected mucosal damage, consultation with a gastroenterologist is necessary to assess the health of the esophageal lining.
Risk Gradients Based on Temperature and Volume
The data reveals a clear dose-response relationship where both the temperature and the frequency of consumption influence the probability of developing SCC. The risk increases incrementally as the perceived temperature of the drink rises.
Volume also matters. Participants consuming six or more hot beverages per day saw a 71% increase in SCC risk compared to those drinking fewer than six, even after accounting for the temperature of the drinks. This suggests a cumulative effect where both the intensity of the heat and the frequency of exposure contribute to the overall morbidity risk.
SCC Shows Strong Association While Adenocarcinoma Does Not
A critical distinction in this research is the type of cancer affected. The study found a strong association with esophageal squamous cell carcinoma (SCC), which begins in the flat cells lining the esophagus. However, the researchers found no such connection with esophageal adenocarcinoma, which develops further down the esophagus near the stomach.
This distinction significantly alters the clinical relevance for different populations. Aaron Sasson noted to Fox News that approximately 85% of esophageal cancers diagnosed in the United States are adenocarcinomas. He estimated that the lifetime risk of SCC for Americans is under 1%, meaning the findings have a more profound impact on populations where SCC is more prevalent than in the general U.S. population.
Limitations of Self-Reported Data and IARC Guidelines
The study relies on self-reported preferences—categories such as “very hot,” “hot,” and “warm”—rather than absolute temperature measurements. This limitation means the exact Celsius or Fahrenheit threshold for “very hot” in a Western context remains unconfirmed. However, the findings suggest that the risk may extend to temperature ranges lower than the 65°C (149°F) threshold previously classified as “probably carcinogenic to humans” by the International Agency for Research on Cancer (IARC) in 2016.
Despite the lack of absolute measurements, the researchers estimate that if individuals who currently drink beverages at a “very hot” temperature shifted to “hot,” roughly 14% of SCC cases could be prevented. In the United Kingdom, this would translate to approximately 440 prevented cancer cases annually.
Because these are observational findings, they establish an association rather than a direct causal link. Nevertheless, the alignment with animal studies—which show that 70°C water promotes premalignant lesions while lower temperatures do not—strengthens the biological plausibility of the claim. Individuals with a family history of esophageal cancer or those exhibiting symptoms like dysphagia (difficulty swallowing) should seek screening from an oncology specialist or a diagnostic imaging center to monitor for early cellular changes.
Future research will likely focus on obtaining objective temperature data to define the exact safety threshold for hot beverage consumption. Until then, the clinical evidence suggests that allowing a beverage to cool slightly before consumption may significantly reduce the risk of thermal mucosal injury.
Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.