Aug 20, 2025 12:30:00

Experts explain that drinking hot tea or coffee may cause cancer, and the trick is to drink it in small amounts

Hot drinks like tea and coffee can be comforting and soothing, but drinks that are too hot may increase your risk of cancer, explains Associate Professor

Vincent Ho, a gastroenterologist at Western Sydney University .

Do hot drinks really give you cancer? A gut expert explains
https://theconversation.com/do-hot-drinks-really-give-you-cancer-a-gut-expert-explains-261256

So far, no link has been found between hot drinks and laryngeal or stomach cancer , but a link has been found with esophageal cancer . In 2016, the International Agency for Research on Cancer, a division of the World Health Organization (WHO), classified drinking very hot drinks (over 65°C) as ' probably carcinogenic to humans .' This category also includes 'eating large amounts of red meat' and 'fumes released from indoor wood burning.'

The International Agency for Research on Cancer's classification is based on a study examining the association between mate, a herbal drink primarily consumed in South America, and esophageal cancer. Mate is typically consumed at a high temperature of about 70°C, and the study found that heavy consumption of mate was associated with an increased risk of esophageal cancer.

Studies in the Middle East, Africa, and Asia have also confirmed the link between very hot drinks and esophageal cancer: A 2025 study of nearly 500,000 UK adults found that people who drank eight or more cups of very hot tea or coffee per day were almost six times more likely to develop esophageal cancer than those who did not drink hot drinks.

One long-standing theory about why drinking very hot beverages increases the risk of esophageal cancer is that hot beverages damage the lining of the esophagus, leading to long-term cancer development. Researchers have conducted animal studies to study the damage caused by hot beverages to the esophagus.

A 2016

study found that mice orally administered hot water (approximately 70°C) developed esophageal cancer precursor lesions more frequently and earlier than mice given water at a lower temperature.

Another theory is that hot drinks may damage the esophageal mucosa, weakening its normal barrier function and increasing the damage caused by acid reflux. Long-term accumulation of chronic damage from acid reflux may increase the risk of developing esophageal cancer.

The risk of esophageal cancer may also depend on the amount of hot beverage consumed at one time.

A study measuring the temperature inside the esophagus when drinking coffee of various temperatures found that the amount consumed had a stronger effect than the temperature of the beverage. Drinking a very large amount of 65-degree coffee, '20 ml in one sip,' can raise the temperature inside the esophagus by up to 12 degrees. This can cause persistent heat damage and potentially damage esophageal cells.

'Drinking a small amount of 65-degree coffee occasionally is unlikely to cause long-term problems, but drinking large amounts of very hot drinks over many years may increase your risk of esophageal cancer,' Ho said.

Coffee and other beverages are often brewed at temperatures exceeding 90°C, and takeaway hot drinks are often served at around 90°C, with the intention of being consumed at the office or at home. An American study concluded that the optimal temperature for coffee is 57.8°C, which preserves the flavor and taste while minimizing the risk of damage to the esophagus.

Ho's advice for drinking hot drinks safely is as follows:

・Take your time and enjoy it.
- Stir hot drinks, open the lid if taking out, or add cold water or milk to cool them down before drinking.
- If you want to check the temperature of a drink, sip small amounts to minimize damage to your esophagus.