For many people, starting the day with a hot cup of coffee or enjoying a freshly brewed tea is part of a daily routine. In many regions of the world, beverages such as coffee, tea, and mate also hold deep cultural and social significance. For years, researchers investigated whether certain beverages, particularly coffee and mate, might be associated with cancer development. However, as scientific research advanced, investigators began to notice an interesting pattern: the risk appeared to be more closely related to the temperature of the beverage than to the beverage itself.
Although this idea may seem surprising at first, a growing body of evidence suggests that the temperature of a beverage may be just as important as its chemical composition. In fact, the International Agency for Research on Cancer (IARC), a specialized agency of the World Health Organization, has evaluated this issue and concluded that the consumption of very hot beverages may represent a potential risk factor for certain types of cancer, particularly esophageal cancer.
This observation led researchers to rethink the original question. Rather than focusing solely on what people drink, scientists began examining how they drink it. The results showed that individuals who regularly consume beverages at very high temperatures, generally above 60–65°C (140–149°F), have an increased risk of developing esophageal squamous cell carcinoma, one of the most common forms of esophageal cancer in many parts of the world.
These findings have been supported by studies conducted across multiple continents, including Asia, South America, the Middle East, and Europe, strengthening the hypothesis that repeated thermal injury may play an important role in the development of this disease.
The Esophagus: A Continuously Exposed Tissue
To better understand this possible association, it is important to understand the role of the esophagus. This muscular tube connects the throat to the stomach and allows food and liquids to pass during swallowing.
The inner surface of the esophagus is lined with specialized cells that, while resistant to the normal passage of food and beverages, can be affected when repeatedly exposed to extremely high temperatures.
When a person frequently consumes very hot beverages, the esophageal tissue may experience repeated minor thermal injuries. In most cases, the body is capable of repairing this damage. However, when exposure occurs over many years, repair mechanisms must be activated continuously, resulting in a constant process of cellular renewal.
It is within this context that researchers believe the likelihood of biological errors leading to the development of abnormal cells may increase.
Furthermore, when tissues are repeatedly exposed to high temperatures, local inflammatory processes may be triggered. Inflammation is a natural response to injury, but when it persists over long periods, it can disrupt the normal biological balance of cells.
Some researchers have also suggested that thermal injury may increase the vulnerability of esophageal tissue to other known risk factors, such as tobacco use, alcohol consumption, or certain dietary carcinogens.
Figure 1. Proposed relationship between very hot beverage consumption and esophageal cancer risk. Repeated thermal injury may promote chronic inflammation, genetic alterations, and tissue changes that contribute to carcinogenesis, particularly in the presence of additional risk factors such as tobacco and alcohol exposure.
The Strongest Scientific Evidence to Date
One of the most important studies on this topic was conducted in the Golestan Cohort in Iran, a region with a particularly high incidence of esophageal cancer. Researchers followed more than 50,000 individuals over several years and evaluated their tea-drinking habits.
The results showed that individuals who consumed tea at temperatures above 60°C had a significantly higher risk of developing esophageal squamous cell carcinoma compared with those who allowed their beverages to cool before drinking.
This study was especially important because it directly measured beverage temperatures rather than relying solely on participants’ perceptions, providing more accurate and reliable data.
In addition, multiple systematic reviews and meta-analyses have reached similar conclusions, consistently reporting an association between the habitual consumption of very hot beverages and an increased risk of esophageal cancer.
Do All Hot Beverages Carry the Same Risk?
Current evidence indicates that temperature itself is the key factor, rather than the specific type of beverage consumed. This means that coffee, tea, herbal infusions, and mate may produce similar effects when consumed at sufficiently high temperatures.
This observation has allowed researchers to move beyond earlier concerns regarding specific chemical components of these beverages and focus instead on the physical effects of heat on esophageal tissue.
Should We Stop Drinking Coffee or Tea?
The answer is NO.
There is currently no evidence supporting the elimination of coffee or tea consumption because of cancer concerns related to beverage temperature. In fact, numerous studies have shown that some of these beverages contain bioactive compounds that may provide health benefits.
The primary recommendation is not to avoid these beverages but rather to allow them to cool slightly before consumption. Waiting a few minutes after pouring a hot drink may be enough to significantly reduce the esophagus’s exposure to potentially harmful temperatures.
A Balanced Perspective
As with many cancer-related factors, the consumption of very hot beverages should not be interpreted as a single or inevitable cause of disease. Cancer is a complex process influenced by multiple genetic, environmental, and lifestyle factors.
Nevertheless, the scientific evidence accumulated over recent decades suggests that repeated exposure to high temperatures may contribute to the development of esophageal cancer under certain circumstances. For this reason, international health organizations and public health experts consider it prudent to adopt simple measures to reduce this exposure.
Ultimately, enjoying a cup of coffee or tea remains compatible with a healthy lifestyle. The difference may simply lie in having a little more patience before taking that first sip.
Main reference:
Loomis, D., Guyton, K. Z., Grosse, Y., Lauby-Secretan, B., El Ghissassi, F., Bouvard, V., Benbrahim-Tallaa, L., Guha, N., Mattock, H., Straif, K., & International Agency for Research on Cancer Monograph Working Group (2016). Carcinogenicity of drinking coffee, mate, and very hot beverages. The Lancet. Oncology, 17(7), 877–878. https://doi.org/10.1016/S1470-2045(16)30239-X
Other references:
IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. (2018). Drinking Coffee, Mate, and Very Hot Beverages. International Agency for Research on Cancer. https://pubmed.ncbi.nlm.nih.gov/31310458/
Chen, Y., Tong, Y., Yang, C., Gan, Y., Sun, H., Bi, H., Cao, S., Yin, X., & Lu, Z. (2015). Consumption of hot beverages and foods and the risk of esophageal cancer: a meta-analysis of observational studies. BMC cancer, 15, 449. https://doi.org/10.1186/s12885-015-1185-1
Islami, F., Boffetta, P., Ren, J. S., Pedoeim, L., Khatib, D., & Kamangar, F. (2009). High-temperature beverages and foods and esophageal cancer risk–a systematic review. International journal of cancer, 125(3), 491–524. https://doi.org/10.1002/ijc.24445
