UK-based researchers have identified a link between regularly drinking beverages at very high temperatures and an elevated risk of oesophageal cancer, also referred to as cancer of the food pipe. The study, led by Oxford University and published in the International Journal of Cancer, is described as the largest of its kind to date, analyzing data from nearly one million participants.
According to the findings, individuals who habitually consumed drinks classified as “very hot” faced approximately three times the risk of developing the disease compared to those who preferred their tea or coffee at warm temperatures. The researchers defined “very hot” as any liquid at 65 degrees Celsius or above. However, they emphasized that while the relative risk increases, the absolute probability of developing this specific cancer remains low.
The potential harm stems from the physical damage scalding liquids can cause to the cell lining of the food pipe as they travel toward the stomach. The data, drawn from 977,282 middle-aged men and women, indicated that consuming six or more of these hot drinks daily further elevated the risk. Researchers noted that adding milk may lower the temperature only slightly, meaning a milky brew could still pose a threat if served at boiling point.
Dr. Keren Papier, the lead researcher, highlighted that previous studies in South America had observed similar connections between oesophageal cancer and the consumption of mate, a herbal beverage typically drunk piping hot. She called for further research to pinpoint the exact temperature thresholds associated with increased risk.
Practical guidance on cooling times remains difficult to standardize. Cancer Research UK suggested that consumers should wait until a drink is comfortable to consume rather than ingesting it while it is steaming. For context, coffee straight from a fully boiled kettle sits at 100 degrees Celsius and cools to roughly 90–95 degrees Celsius once poured. A separate study involving young adults found that most only perceived black coffee as too hot once it reached 70 degrees Celsius.
Industry standards vary; takeaway coffee is typically served between 49 and 60 degrees Celsius, though requests for “extra hot” can result in temperatures exceeding 82 degrees Celsius. The researchers estimated that between one and two in every ten cases of oesophageal squamous cell carcinoma could be prevented if people ceased drinking very hot beverages.
Despite the findings, health charities stressed that lifestyle factors such as smoking and alcohol consumption remain far more significant drivers of oesophageal cancer. Fiona Osgun from Cancer Research UK, which funded the study, advised that the most effective ways to reduce risk are avoiding tobacco and limiting alcohol intake. Symptoms of the disease can include persistent heartburn, indigestion, throat or chest pain, and unexplained weight loss.
Finally, a reason to be patient with my morning coffee! Though waiting five minutes feels like an eternity.
The researchers mentioned mate tea specifically. I guess I need to be careful with my afternoon brew too.
Makes me wonder about takeaway coffee chains. How many ‘extra hot’ orders actually exceed that danger zone?
This is worrying, but smoking and alcohol are still way bigger risks. Don’t lose sleep over the temperature!
I never knew about the 65-degree threshold. I’ll let my tea cool down a bit more before taking that first sip.