Tea and coffee are misunderstood to be bad for us, but polyphenols and antioxidants are abundantly present in them. However, some studies suggest that regular consumption of tea and coffee could increase the risk by reducing oxidative stress and inflammation. Not only this, excessive intake of very hot beverages has been linked to an increased risk of head and neck cancer. This happens because of an increased risk due to heat injury to the inner lining of our oral cavity.
Coffee and tea may cause oropharyngeal cancer by causing thermal injury to the oropharyngeal mucosa. If so, the risk of oropharyngeal carcinoma attributable to thermal injury could be large in populations in which these beverages are commonly consumed. In addition, these drinks may cause or prevent oropharyngeal carcinoma
via their chemical constituents.Therefore, a large number of epidemiologic studies have investigated the association of an indicator of amount or temperature of use of these drinks or other hot foods and beverages with the risk of oral cancer (OC).
According to Yash Mathur – Consultant- Head & Neck Surgical Oncology – HCG Hospital, Colaba, “We conducted a systematic review of these studies and report the results for amount and temperature of use separately. By searching PubMed and the ISI, we found 59 eligible studies. For coffee and tea,there was little evidence for an association between amount of use and carcinoma risk; however, the majority of studies showed an increased risk of OC associated with higher drinking temperature, which was statistically significant in most of them.”
The number of studies was limited, but they consistently showed that OC risk increased with both amount consumed and temperature, and these 2 were independent risk factors. For other hot foods and drinks, over half of the studies showed statistically significant increased risks of oropharyngeal carcinoma associated with higher temperature of intake.
According to Dr. Jeyhan B. Dhabhar, Consultant, Medical Oncologist and cancer expert, Jaslok Hospital & Research Centre, Mumbai, Overall, the available results strongly suggest that high-temperature beverage drinking increases the risk of oral carcinoma. Future studies will require standardized strategies that allow for combining data and results should be reported by histological subtypes of carcinoma. Some studies support the hypothesis of an inverse association between caffeinated coffee drinking and OP cancer risk. We pooled individual-level data from nine case-control studies of HN cancers, including 5139 cases and 9028 controls.”
The inverse relationship between caffeinated coffee drinking and OP cancer can be related to various components of coffee. Besides caffeine, coffee contains more than a thousand chemicals, some of which have antioxidant and antimutagenic activities in animal models and cell culture systems. These include several phenolic compounds (such as chlorogenic, caffeic, ferulic, and cumaric acids), melanoidins, and diterpenes (such as cafestol and kahweol), whose concentration in the beverage varies depending on type of raw coffee (Arabica or Robusta), roasting, and preparation, as unfiltered coffee contains fewer amounts of lipid components, such as diterpenes. In particular, cafestol and kahweol may reduce the genotoxicity of some carcinogens and may activate enzymes involved in cancerogenic detoxification, such as glutathione-S-transferase and inhibiting N-acetyltransferase.
Another head and neck cancer study to consider
The INHANCE consortium includes 33 epidemiologic studies providing data on 24,571 cases of HN cancers and 33,013 controls from many countries and regions, including carcinomas of the oral cavity, pharynx, and larynx, and excluding lymphomas and sarcomas, and cancers of the nasopharynx and salivary glands. Among the 33 studies, 23 had no information on coffee or tea drinking and thus could not be included in this investigation. Another study was excluded because data on caffeinated coffee and tea amounts were missing for 46% and 67% of cases and 28% and 51% of controls, respectively. Therefore, nine studies reporting information on caffeinated coffee, decaffeinated coffee, or tea drinking were included. All nine case-control studies included OP cancer, and 7 studies included also laryngeal cancer.
In conclusion, the results of this pooled analysis of case-control studies support the hypothesis of an inverse association between caffeinated coffee drinking and OP cancer risk and provide a more precise estimate of the magnitude of the effect.