Study Investigates Hot Tea Consumption and Oesophageal Cancer Risk
Overview of Tea Drinking Habits
A recent study conducted in China explored the potential link between drinking very hot tea and the increased risk of oesophageal cancer, particularly in conjunction with established risk factors such as smoking and alcohol consumption. Tea is a widely enjoyed beverage globally, though concerns have been raised about the effects of very hot tea on the oesophagus, the tube that carries food and drinks to the stomach. Prolonged exposure to high temperatures could potentially damage the oesophageal lining, contributing to cancer risk. While these concerns have been debated for years, they have not been conclusively proven. It is well-established that smoking and excessive alcohol intake are significant risk factors for oesophageal cancer, which is notably prevalent among men in Asian countries, particularly China.
Details of the Chinese Cohort Study
As reported in The BMJ, this comprehensive Chinese prospective cohort study aimed to assess whether the consumption of very hot tea elevates the risk of oesophageal cancer, especially when combined with smoking and high alcohol consumption. The study involved 456,155 participants aged between 30 and 79 years. Participants were surveyed about their tea consumption frequency and temperature preferences (categorized as warm, hot, or very hot). Additionally, information regarding their smoking status and daily alcohol intake (15g or more) was collected, with 15g being roughly equivalent to a standard serving of wine.
Findings on Cancer Risk
Over a nine-year follow-up period, 1,731 participants received a diagnosis of oesophageal cancer. The results indicated that those who regularly consumed very hot tea, along with smoking and excessive alcohol consumption, exhibited a heightened risk of developing oesophageal cancer compared to individuals who consumed only very hot tea. Specifically, the risk increased five-fold for participants who drank very hot tea and consumed excessive amounts of alcohol compared to those who drank less frequently and consumed under 15g of alcohol daily. Furthermore, the cancer risk doubled for smokers who also drank hot or very hot tea.
Interaction of Hot Tea with Smoking and Alcohol
The researchers observed that there was no significant increase in oesophageal cancer risk among participants who drank hot tea but did not smoke or consume alcohol. This finding suggests that while hot tea may not independently pose a risk, it can exacerbate the cancer risk associated with smoking and alcohol consumption. The damaging effects of very hot tea on the oesophageal lining may render it more susceptible to the harmful effects of these substances.
Limitations of the Study
Despite its rigorous nature, the study has limitations, particularly regarding potential bias since participants self-reported their drinking and smoking habits. Additionally, the researchers could not track changes in these habits over the nine-year period, as data were only collected at the study’s onset.
Conclusion and Future Directions
Overall, this study highlights that individuals who consume hot or very hot tea in conjunction with high alcohol intake and/or smoking face a higher risk of developing oesophageal cancer compared to those who do not engage in these behaviors. Further research in diverse populations, particularly those with a higher prevalence of oesophageal cancer, is essential to expand on these findings.
References
(1) Wise, J. Drinking very hot tea linked to oesophageal cancer. BMJ. 2018;360:k543. doi: 10.1136/bmj.k543.
(2) Yu C, Tang H, Guo Y, et al. Effect of hot tea consumption and its interactions with alcohol and tobacco use on the risk of esophageal cancer: a population based cohort study. Ann Intern Med. 2018. doi:10.7326/M17-2000. Abstract only.
(3) Summaries for patients. Hot Tea Consumption and the Risk for Esophageal Cancer. Ann Intern Med. [published online 6 February 2018]. doi:10.7326/P17-9054.