Very Hot Tea and Coffee Linked to Threefold Increase in Risk of Specific Esophageal Cancer

Drinking scalding hot tea and coffee is linked to a sharp increase in the risk of developing esophageal squamous cell carcinoma, according to Oxford University epidemiologists who analyzed data from nearly one million UK residents. The findings of the large-scale prospective study were published in the International Journal of Cancer.

Data from One Million People and a Threefold Statistical Gap

Researchers combined medical records from two major UK health studies: the Million Women Study and UK Biobank. The combined sample included 977,282 participants whose health was continuously monitored over 11 to 14 years. During this period, participants were diagnosed with 2,348 cases of malignant esophageal tumors: 1,045 squamous cell carcinomas and 1,303 adenocarcinomas.

Survey participants reported their preferred temperature for everyday beverages, choosing between “warm,” “hot,” and “very hot.”

Comparing the data revealed a strong temperature dependency:

• Those who preferred “very hot” tea and coffee had a 3.2 times higher risk of esophageal squamous cell carcinoma compared to those who preferred warm drinks;
• In the “hot” beverage category, the risk of developing the tumor was 69% higher;
• Total volume served as an additional factor: consuming six or more cups per day increased the risk of squamous cell carcinoma by another 71%, regardless of temperature;
• Meanwhile, researchers found no statistically significant link between beverage temperature and esophageal adenocarcinoma.

Thermal Burns Rather Than Caffeine Harm

The authors emphasize that the danger lies not in the chemical composition of coffee or tea leaves, but solely in the physical temperature of the liquid.

Boiling liquids cause repeated micro-burns to the esophageal epithelium. Chronic thermal damage triggers persistent tissue inflammation, weakens the mucosal barrier function, and makes cells more vulnerable to tobacco smoke, alcohol, and other external carcinogens.

Oncologists have warned about this risk before. Back in 2016, the International Agency for Research on Cancer (IARC), an agency of the World Health Organization, classified drinking any beverage above 65°C as “probably carcinogenic to humans” (Group 2A).

Because the study is observational, researchers established direct cause and effect using statistical models. According to Oxford analysts’ calculations, if hot coffee drinkers allowed their cups to cool to a moderate temperature before the first sip, up to 14% of all esophageal squamous cell carcinoma cases could be prevented. Doctors advise a simple rule of thumb: refrain from drinking freshly brewed tea immediately and wait 4 to 6 minutes after pouring boiling water into a mug.