Regular consumption of very hot drinks may almost triple the risk of squamous cell carcinoma of the oesophagus. Researchers at the University of Oxford reached this conclusion after analysing data from nearly one million people in the UK. At the same time, the researchers emphasise that the problem is likely not the tea or coffee itself, but the high temperature of the drink.
- The study involved around 980,000 people.
- «Very hot» drinks have been linked to an almost threefold increase in the risk of one type of oesophageal cancer.
- For «hot» drinks, the risk was approximately 1.7 to 2 times higher.
- It is the temperature itself, rather than tea or coffee, that is the likely factor.
- The WHO classifies drinks hotter than 65°C as «probably carcinogenic».
What a new study has revealed
The team Oxford Population Health analysed data on approximately 980,000 adults from the UK Biobank and the Million Women Study. The participants’ health was monitored for over ten years.
People were asked how they usually drink hot drinks — lukewarm, hot or very hot.
Compared with those who preferred hot drinks, among coffee lovers hot For those who consumed alcoholic drinks, the risk of developing squamous cell carcinoma of the oesophagus was almost twice as high. Among those who described their drinks as «very hot», the risk was approximately three times higher.
The study was published on 9 September in International Journal of Cancer. This is the largest study of its kind carried out amongst the population of Great Britain.
Six or more hot drinks a day also increased the risk
Researchers found a link not only with temperature but also with the number of drinks consumed. According to the study, consumption of six or more hot drinks a day was associated with an approximately 71% higher risk of squamous cell carcinoma of the oesophagus.
At the same time, it is important to note that this concerns relative risk. This type of cancer itself remains relatively rare: Cancer Research UK estimates the lifetime risk of squamous cell carcinoma of the oesophagus in the UK to be approximately 1%.
In other words, the new findings do not mean that people who regularly drink hot coffee are at a high risk of developing cancer.
Why it is dangerous to drink beverages that are too hot
Researchers suggest that high temperatures may damage the mucous membrane of the oesophagus. Repeated thermal damage and inflammation over a long period of time may potentially contribute to the development of malignant changes in cells.
This hypothesis is not new. The International Agency for Research on Cancer (IARC), which is part of WHO, back in 2016, classified the consumption of drinks by temperature over 65°C as «probably carcinogenic to humans» — Group 2A.
At the same time, the IARC emphasised that the data specifically indicate temperature, rather than on the properties of coffee, tea or mate. For example, hot or cold mate did not show the same association with oesophageal cancer.
Should you give up coffee and tea?
No. A new study did not show that tea or coffee, on their own, increase the risk. The correlation was observed specifically with the temperature of the drink.
Scientists also point out that the study is observational: it shows a consistent link, but cannot conclusively prove that the hot drink was the cause of the illness. Furthermore, the participants estimated the temperature of their drinks themselves, rather than measuring it with a thermometer.
The simplest piece of advice is — Don’t drink tea or coffee whilst they’re scalding hot; let them cool down a little. The IARC classifies temperatures above 65°C as «very hot».
At the same time, Cancer Research UK emphasises that the following remain the most significant proven risk factors for squamous cell carcinoma of the oesophagus: smoking and alcohol consumption.
