Large Study Links Very Hot Tea and Coffee to Threefold Esophageal Cancer Risk

Key facts

According to reporting by Tudor Tarita, a landmark study encompassing one million participants has provided substantial new empirical evidence linking hot beverage consumption to upper gastrointestinal cancers. Researchers evaluated long-term dietary patterns, drinking habits, and health outcomes across the expansive participant cohort to assess how liquid temperatures influence oncological risk over extended periods.

The data revealed that individuals who routinely drank tea or coffee at very high temperatures faced up to three times the likelihood of developing esophageal cancer compared to those who drank cooler beverages or avoided scalding liquids entirely. Crucially, the research determined that the physiological driver of this risk is physical thermal trauma rather than the biochemical composition of the drinks themselves.

When liquids at elevated temperatures enter the throat, they cause acute micro-thermal burns to the squamous epithelial cells lining the esophageal tract. While isolated instances of minor burning heal quickly, chronic exposure over years or decades creates a continuous cycle of tissue injury, inflammation, and rapid cellular repair. During these sustained cycles of forced cellular regeneration, the probability of genetic mutations and abnormal cellular replication increases significantly, eventually creating fertile ground for malignant tumor formation.

Why it matters

Tea and coffee represent two of the most widely consumed beverages in the world, with global daily consumption estimated in the billions of cups. Because drinking hot beverages is a deeply embedded daily habit across virtually every culture, even a moderate shift in relative disease risk carries massive public health implications worldwide.

From a preventive health perspective, the study's conclusions offer a remarkably straightforward intervention. Unlike environmental toxins or genetic predispositions that require complex medical therapies or sweeping regulatory overhauls to address, the risk associated with hot beverage consumption can be largely neutralized through simple behavioral changes. Consumers do not need to give up tea or coffee, nor do they need to forgo the beneficial antioxidants, polyphenols, and cognitive compounds contained within these drinks. Instead, simply allowing beverages to cool for three to five minutes, stirring them, or adding a small amount of cold liquid can bring consumption temperatures down into a safe range, dramatically reducing thermal injury to esophageal tissues.

For healthcare systems and oncologists, the study highlights the importance of incorporating routine dietary temperature inquiries into standard clinical screenings, particularly for patients presenting with early symptoms of upper digestive discomfort such as difficulty swallowing or chronic acid reflux. Furthermore, commercial coffee retailers, food safety authorities, and workplace equipment manufacturers may re-evaluate automated brewing and serving guidelines to minimize the risk of thermal harm to consumers.

Esophageal cancer is the sixth leading cause of cancer-related mortality globally, responsible for more than 500,000 deaths annually according to international health data. The disease manifests primarily in two distinct histological forms: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). While adenocarcinoma is more prevalent in Western nations and is strongly linked to obesity and chronic gastroesophageal reflux disease, squamous cell carcinoma accounts for the majority of global cases, particularly across Asia, East Africa, and South America.

Squamous cell carcinoma arises in the thin, flat cells lining the interior of the esophagus. Historically, tobacco use and heavy alcohol intake were recognized as the primary risk factors for ESCC in high-income countries. However, epidemiological investigations in non-Western populations frequently uncovered high rates of ESCC among demographics with low rates of smoking and alcohol use, pointing toward regional dietary customs as alternative causative agents. In regions such as northern Iran, southern Brazil, Uruguay, eastern Turkey, and northwestern China, traditional customs favor drinking tea or yerba maté at temperatures frequently exceeding 70 degrees Celsius (158 degrees Fahrenheit).

In 2016, an international working group of 23 scientists convened by the International Agency for Research on Cancer (IARC), the specialized cancer agency of the World Health Organization, conducted a comprehensive evaluation of the carcinogenicity of coffee, maté, and hot beverages. After reviewing over 1,000 human and animal studies, the IARC officially classified the consumption of very hot beverages—defined specifically as liquids consumed at temperatures above 65 degrees Celsius (149 degrees Fahrenheit)—as "probably carcinogenic to humans" (Group 2A). Concurrently, the agency re-evaluated coffee, removing its previous 1991 classification as "possibly carcinogenic" (Group 2B) and placing it in Group 3 ("not classifiable as to its carcinogenicity to humans"), explicitly concluding that temperature, not the coffee bean itself, was responsible for observed esophageal cancer risks. The million-person findings reported by Tudor Tarita build directly upon this historical scientific consensus, offering unprecedented statistical power to quantify the risk magnitude across diverse populations.

Reaction

Following the report by Tudor Tarita, medical professionals, gastroenterologists, and public health advocates are expected to reinforce long-standing advice regarding thermal injury prevention. Oncology experts typically emphasize that coffee and tea possess well-documented health benefits, including reduced risks for liver cirrhosis, type 2 diabetes, and certain cardiovascular conditions. Consequently, public health responses will likely focus on educational messaging centered on temperature control rather than dietary restriction.

Food safety organizations and consumer advocacy groups may also use the research to call for clearer temperature standards across the commercial food service industry. In commercial coffee shops, espresso and drip coffee are typically brewed at temperatures between 85 and 95 degrees Celsius (185 to 203 degrees Fahrenheit) to extract optimal flavor, and takeout cups are frequently served to customers at temperatures exceeding 75 degrees Celsius (167 degrees Fahrenheit). Industry groups may face pressure to evaluate cup design, lid airflow, and warning labels to ensure consumers are informed about the hazards of drinking freshly poured liquids immediately.

What we don't know yet

While the million-person study provides robust statistical backing for the link between high-temperature liquids and esophageal cancer, several critical questions remain unanswered in the initial reporting by Tudor Tarita. First, the precise temperature spectrum utilized in the study's participant surveys has not been fully detailed, leaving it unclear whether the threefold risk applies exclusively to extreme temperatures above 70 degrees Celsius or begins at lower thresholds such as 60 degrees Celsius.

Second, the degree to which thermal injury interacts with co-factors such as tobacco smoking, alcohol consumption, gastric reflux, or genetic susceptibility remains to be fully elucidated. It is currently unknown whether thermal injury acts independently or serves as a synergistic amplifier that makes esophageal tissue more vulnerable to chemical carcinogens in tobacco smoke or alcohol.

Third, the long-term observational nature of large cohort studies relies heavily on self-reported dietary habits, which can introduce recall bias. Finally, further research is needed to determine the exact duration of exposure required before thermal damage leads to irreversible dysplastic changes in the esophageal epithelium.

What to watch

In the coming months, public health analysts and clinicians will be looking for the full, peer-reviewed publication of the million-person study in a major medical journal. Access to the full dataset will allow independent researchers to examine subgroup analyses based on age, sex, geographic region, and specific beverage types.

Additionally, key developments to monitor include:

This report is based on scientific news coverage originally reported by Tudor Tarita on September 16, 2026.