Most cancer-prevention messaging around beverages focuses on alcohol or sugar content — but the temperature at which people drink their tea or coffee may be an underappreciated and modifiable risk factor for a particularly lethal cancer subtype. This finding matters because oesophageal squamous cell carcinoma carries a five-year survival rate below 20%, and identifying avoidable exposures in Western populations — where the temperature-cancer link was previously thought to be less relevant — is clinically meaningful.
Drawing on nearly one million UK adults across two large prospective cohorts (the Million Women Study and UK Biobank), researchers tracked 2,348 incident oesophageal cancers over follow-up periods averaging 11–14 years. Participants who reported preferring drinks at a "very hot" temperature faced more than three times the risk of squamous cell carcinoma (SCC) compared to those preferring "warm" drinks (RR = 3.17; 95% CI: 2.49–4.03), with no meaningful elevation in adenocarcinoma risk. High-frequency consumption — six or more hot drinks daily — was independently associated with a 71% increase in SCC risk, even after adjusting for temperature preference. Crucially, the researchers estimated that 14% of SCC cases in UK adults could theoretically be prevented if very-hot-drink consumers shifted to cooler temperatures.
This study adds important Western-population data to a body of evidence largely built on populations in Iran, China, and South America, where drinking temperatures routinely exceed 70°C. The temperature thresholds in the UK cohorts were self-reported rather than measured, a limitation that likely introduces misclassification and may compress the observed effect sizes — meaning the true biological gradient could be steeper. The mechanistic hypothesis centers on repeated thermal injury to the oesophageal epithelium, promoting mucosal inflammation and carcinogenic transformation, consistent with IARC's 2016 classification of very hot beverages as probable carcinogens (Group 2A). Adenocarcinoma, driven primarily by gastroesophageal reflux and obesity, showed no temperature association — reinforcing that these are etiologically distinct tumors. The study's scale and prospective design make it among the most statistically robust investigations of this question in a Western context, elevating it from a plausible hypothesis to an evidence-grounded population-level concern.