Very hot drinks increase oesophageal cancer risk, UK study finds

LONDON — A new large-scale study has found that drinking beverages "very hot" triples the risk of developing oesophageal squamous cell carcinoma (SCC) compared to those who drink them warm. While researchers emphasize that the overall risk of this cancer remains very small, the findings provide the most comprehensive evidence to date regarding how beverage temperature affects the UK population. The study suggests that the physical heat may damage the cells lining the oesophagus, potentially creating a pathway for cancer to develop.

Scale and Scope of the Oxford Study

Experts from Oxford Population Health at the University of Oxford conducted the analysis, combining data from two massive datasets: the UK Biobank and the Million Women Study. In total, researchers examined the habits of approximately 980,000 adults across the UK. The project, funded by Cancer Research UK, sought to determine if the risks associated with very hot drinks in other parts of the world applied to Western populations. Dr Keren Papier, lead researcher and senior nutritional epidemiologist at Oxford Population Health, noted that international research had previously linked the consumption of mate — a beverage typically consumed at very high temperatures in South America, to increased cancer risks.

Quantifying the Thermal Risk

The study identified a clear escalation of risk based on the perceived temperature of the beverage. Those who reported enjoying their drinks "hot" faced a 1.7 times higher risk, while the "very hot" group saw that risk climb to three times that of people who drank beverages warm.

Perceived Drink Temperature	Risk Multiplier (vs. Warm)
Warm	Baseline
Hot	~1.7x
Very Hot	~3x

Beyond temperature, the volume of consumption played a role. According to the research, individuals consuming six or more hot drinks per day experienced an increased risk compared to those drinking fewer than six. The Mirror reported that certain beverage choices may carry higher risks, specifically noting that black coffee, black tea, and herbal teas consumed without milk could be more problematic.

Biological Distinctions and Global Benchmarks

Medical professionals distinguish between the two primary forms of oesophageal cancer: adenocarcinoma and squamous cell carcinoma (SCC). The study found that while temperature significantly affected the risk of SCC, there was no obvious impact on the risk of adenocarcinoma. In the UK, there are approximately 9,500 cases of oesophageal cancer annually. The lifetime risk for a UK resident to be diagnosed specifically with SCC is around 1%. To provide a scientific benchmark for "very hot," researchers referenced a 2016 classification by the International Agency for Research on Cancer, which labeled beverages above 65C as probably carcinogenic. However, the Oxford study notes that the estimated temperature at which tea and coffee are actually consumed in Western populations is around 60C.

Contextualizing the Danger

Despite the risk multipliers, clinicians urge the public not to panic. Fiona Osgun, head of health information at Cancer Research UK, stated:

"While the risk of being diagnosed with this cancer remains relatively low in the UK, this research does add to the evidence that drinking very hot drinks could increase the risk of oesophageal squamous cell carcinoma."

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Fiona Osgun, head of health information at Cancer Research UK, via Rte

Osgun further clarified that while cooling drinks is a helpful step, the most critical methods for reducing the risk of this specific cancer are avoiding smoking and reducing alcohol consumption. The Mirror also cited acid reflux as a known risk factor for oesophageal cancer.

Frequently Asked Questions

Does adding milk to my tea reduce the cancer risk?

Yes. Experts agree that adding cold milk or simply letting the drink cool down before sipping can negate the risk associated with high temperatures.

What is the temperature threshold for concern?

The International Agency for Research on Cancer classified beverages above 65C as "probably carcinogenic," though typical Western consumption is estimated at 60C.

Is the risk high for the average person?

No. The overall risk is described as "very small," and the lifetime risk of being diagnosed with squamous cell carcinoma in the UK is approximately 1%.

A primary limitation of the study is that it relied on participant self-reporting and general estimates rather than recording the actual physical temperature of the beverages consumed. Dr Papier has indicated that further research is now required to identify the precise drink temperatures that trigger an increased risk of cancer.

Risk Mitigation and Behavioral Factors

While the thermal impact on the oesophagus is a primary focus, the study highlights that the risk is not uniform across all consumption habits. According to reporting by Rte and the Mirror, the risk is linked to the absence of cooling agents. Beverages such as black coffee, black tea, and herbal teas consumed without milk are identified as more problematic because they lack the temperature-reducing effect of cold additives.

These behavioral adjustments are viewed as simple preventative measures. Fiona Osgun of Cancer Research UK noted that while letting a "cuppa" cool is a helpful step, it remains secondary to the most critical risk reduction strategies, which include cutting down on alcohol and avoiding smoking.

Filling the Data Gap

The current findings build upon a trajectory of international research. Dr Keren Papier explained that previous evidence had established a link between oesophageal cancers and the consumption of mate at very high temperatures in South America. The Oxford study was designed to determine if these findings translated to Western populations, where tea and coffee are the primary daily staples.

Despite the scale of the data, a gap remains between perceived temperature and scientific measurement. Because the research relied on how participants described their drinks rather than using thermometers, the exact thermal threshold for UK consumers remains an estimate. As a result, the next step is for researchers to conduct further studies to identify the precise drink temperatures linked to this increased risk.