Your Morning Coffee Could Be Raising Your Cancer Risk — Here's How Hot Is Too Hot

The Danger Is in the Temperature, Not the Drink

Millions of people start their day with a steaming cup of coffee or tea, but a sweeping new study suggests that how hot you drink it may matter far more than most people realize. Drinking beverages very hot, rather than warm, is associated with a three-fold risk of esophageal cancer, according to the study, conducted in the UK and published in the International Journal of Cancer. The research is the largest of its kind to examine this link in a Western population, and its findings are hard to ignore.

Experts from Oxford Population Health at the University of Oxford looked at data from around 980,000 adults by combining two large UK studies — UK Biobank and the Million Women Study. The researchers then tracked participants' health records for over 10 years to see whether they developed esophageal squamous cell carcinoma (SCC). The scale and duration of the study give its conclusions unusual weight.

A Clear and Escalating Risk

Compared to people who reported drinking their beverages "warm," the researchers found that those who preferred their drinks "hot" had nearly two times the risk of esophageal SCC, and those who drank them "very hot" had a three times higher risk. The pattern is unmistakable — the hotter the drink, the greater the danger. The risk also increases with the number of cups consumed daily, with heavy drinkers of hot beverages facing over five times the risk compared to those who drink warm beverages.

The finding applies specifically to esophageal squamous cell carcinoma, the most common form of esophageal cancer worldwide. While drink temperature affected SCC risk in the study, there was no obvious impact on adenocarcinoma risk — the other main type of esophageal cancer. Crucially, researchers emphasize that it's not the beverage itself but the heat that causes harm.

What "Very Hot" Actually Means

Drinking very hot beverages was classified as probably carcinogenic to humans by the International Agency for Research on Cancer (IARC) in 2016, which defines "very hot" as temperatures above 65 degrees Celsius, or 149 degrees Fahrenheit. The new study noted that the temperature at which coffee and tea is drunk in Western populations is estimated to be around 60°C — uncomfortably close to that threshold for many habitual drinkers.

"This is the largest study to date, and it does really add to the evidence that drinking very hot and hot beverages could increase the risk of this type of cancer," said lead study author Keren Papier, a senior nutritional epidemiologist at Oxford Population Health. Previous studies were mostly conducted in South America, Asia, and the Middle East, where drinking cultures are different — making this UK-focused research particularly significant for Western audiences.

A Simple Fix With Potentially Major Benefits

Globally, there were about 604,000 new cases of esophageal cancer and about 544,000 deaths from esophageal cancer in 2020, according to the World Health Organization's cancer agency. In the UK alone, there are around 9,500 cases of esophageal cancer every year, and people there have around a 1% lifetime risk of being diagnosed with SCC.

Letting drinks cool down before drinking or adding cold milk can negate the risk, experts have agreed. That's a remarkably low-effort adjustment for what could be a meaningful reduction in cancer risk. As researchers continue to build on these findings, the message is increasingly clear: there's no shame in letting your morning brew sit for a few extra minutes. Your esophagus will thank you.