Drinking very hot beverages was associated with a threefold higher risk of developing esophageal squamous cell carcinoma (ESCC) than consuming warm beverages, suggested a large new study from the UK that has been making headlines across the globe.

If the link is causal, consuming beverages “hot” instead of “very hot” could prevent an estimated 14% of new ESCC cases, or 440 cancers each year in the UK, researchers reported.

The study of nearly 1 million people is consistent with previous research from countries such as Iran and China, where ESCC is much more common, and with the International Agency for Research on Cancer classification of beverages consumed above 65 °C (149 °F) as “probably carcinogenic” to humans based on limited epidemiologic and experimental evidence.

Several outside experts said the reported association is likely a real effect. But that doesn’t necessarily mean it’s something patients and their physicians need to worry about.

“Esophageal cancer is rare. More importantly, squamous cell carcinoma of the esophagus is declining in incidence,” said Gilbert Welch, MD, general internist at Brigham and Women’s Hospital in Boston, who frequently puts cancer risks into context.

According to the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program, the incidence of esophageal SCC was 1.1 per 100,000 in 2023 — a small fraction of the incidence of other cancer types, such as lung and bronchus (47.9 per 100,000 in 2023) and colorectal (40.5 per 100,000 ).

“Physicians need to prioritize what things to put on patients’ worry list,” said Welch. “Otherwise, they will be overwhelmed and fail to distinguish important risks from trivial ones.”

In the new work, published in the International Journal of Cancer, Keren Papier, PhD, of the University of Oxford in Oxford, England, and colleagues analyzed data from more than 977,000 participants in the Million Women Study and UK Biobank. The participants answered questions about the number of hot drinks they consumed daily and their preferred drinking temperature: “very hot,” “hot,” “warm,” or “do not drink hot drinks.” However, the temperature categories were based on participants’ perceptions and did not correspond to measured beverage temperatures.

In the Million Women Study, there were 799 cases of ESCC and 617 cases of esophageal adenocarcinoma during an average follow-up of about 14 years. The corresponding numbers were 246 ESCC cases and 686 esophageal adenocarcinoma cases over an average follow-up of 11.1 years in the UK Biobank.

After adjusting for the number of hot drinks consumed, the risk for ESCC was significantly higher in people consuming hot (pooled relative risk [RR], 1.69; 95% CI, 1.36-2.11) and very hot drinks (pooled RR, 3.17; 95% CI, 2.49-4.03) than in those who preferred their beverage warm. There was no association, however, between beverage temperature and risk for esophageal adenocarcinoma in either cohort or in pooled analysis (pooled RR, 0.92; 95% CI, 0.76-1.12).

After controlling for drink temperature, people who reported drinking at least six hot drinks per day had a 71% higher pooled risk for ESCC than those consuming fewer than six.

Drink temperature was tied to a higher risk for ESCC in a log-linear fashion (P trend < .0001 in both cohorts and pooled analysis). Incrementally adjusting for potential confounders, such as smoking and alcohol intake, did not materially alter the associations.

Muy-Teck Teh, PhD, professor of Molecular Oral Oncology at Queen Mary University of London in London, England, noted that the main study limitations — namely that perceived drink temperature is inherently subjective and temperature was self-reported — “do not fatally undermine the findings.” Commenting via the Science Media Centre Expert Roundup, Teh, however, cautioned that, given the limitations, “the results should be interpreted as robust associations rather than causal proof.”

Harindra Jayasekara, MD, PhD, of Cancer Council Victoria in Melbourne, Australia, who studies risk factors for esophageal cancer, said that although residual confounding is impossible to rule out, the consistent association “across different populations and exposure sources” and “the dose-response pattern with frequency” strengthen the case that the link is indeed causal.

Although he admitted liking his tea and coffee extra hot, Jayasekara suggested letting “very hot drinks cool before drinking, particularly in susceptible populations.”

Joel H. Rubenstein, MD, of the University of Michigan Medical School in Ann Arbor, Michigan, who specializes in esophageal disease, said the new study and an earlier one that also analyzed data from the UK Biobank are the first to demonstrate the link between beverage temperatures and ESCC in a Western population.

While there could be measurement error given the self-reported drink temperatures, Rubenstein said, “It is hard to imagine how the recall of temperature would be systematically biased to result in the observed association.”

He felt it was “prudent to avoid drinking scalding hot beverages” but added that given the low absolute risks and strong cultural preferences, “individuals can reasonably decide to continue drinking their warm/hot coffee or tea.”

As for what doctors should tell their patients, Jason Oke, DPhil, of the Centre for Evidence-Based Medicine at the University of Oxford suggested: “Nothing unless asked.”

Smoking and alcohol remain the major established risk factors for ESCC. For patients who are very worried, he said, “The fix is simple — switch to iced tea and iced lattes.”

The study had no commercial funding. None of the experts reported relevant financial disclosures.