Regularly consuming beverages at temperatures above 149 degrees Fahrenheit (65 degrees Celsius) could significantly increase the risk of developing esophageal cancer, according to a major study by scientists at the University of Oxford. The research suggests that individuals who prefer their drinks "very hot" are more than three times as likely to develop esophageal squamous cell carcinoma (SCC) compared to those who drink them "warm."
The study, which analyzed data from nearly 980,000 UK adults followed for over a decade, also found that drinking more than six hot beverages per day was associated with a 71% higher risk of the cancer, irrespective of temperature. Esophageal SCC is an aggressive form of the disease, accounting for over 3,000 new cases annually in the UK.
Scientists believe that the heat from very hot drinks can damage the cells lining the upper part of the food pipe, contributing to cancer development. The researchers estimated that approximately 14% of esophageal cancer cases diagnosed in the UK each year could potentially be prevented if people allowed hot drinks to cool before consumption. Early symptoms of esophageal cancer can be mistaken for indigestion, leading to late-stage diagnoses. Survival rates for esophageal cancer remain low, with about a fifth of patients alive five years after diagnosis.
While the study did not directly measure the exact temperature of participants' drinks, it relied on self-reported preferences for 'warm,' 'hot,' or 'very hot.' Previous research has indicated that beverages around 158°F (70°C) are considered very hot, and the International Agency for Research on Cancer classifies drinks above 149°F (65°C) as "probably carcinogenic."
Fiona Osgun, head of health information at Cancer Research UK, which funded the study, noted that while the overall risk of this cancer in the UK is relatively low, the findings add to evidence linking hot beverage consumption to increased risk. She advised a simple preventative measure: allowing a cup of tea or coffee to cool slightly before drinking.
The research found no increased risk for adenocarcinoma, another primary type of esophageal cancer. Major risk factors for esophageal cancer include smoking, obesity, and alcohol consumption, which experts emphasize remain the most critical factors for risk reduction.
Dr. Keren Papier, lead researcher at Oxford Population Health, stated that the study is the largest of its kind in a UK population to investigate the link between usual hot drink consumption temperatures and cancer risk. Further research is needed to pinpoint the precise drink temperatures associated with this elevated risk. Professor Muy-Teck Teh, an expert not involved in the study, urged caution, noting that perceptions of drink temperature can vary and that the study demonstrates a correlation rather than direct causation.