In May, the 2nd Gyeongchun Line Gongneung Forest Path Coffee Festival is held near Gongneung Station in Seoul./Courtesy of Yonhap News

A study has shown that drinking more than 4 cups of coffee a day can reduce the risk of developing head and neck cancer. Tea also had a similar effect, but unlike coffee, frequent consumption of tea was found to be rather risky.

The International Head and Neck Cancer Epidemiology Consortium research team analyzed data from 14 studies conducted in Europe and North and South America and reported on the 24th that coffee and tea consumption may reduce the risk of developing head and neck cancer. The study was published in the American Cancer Society journal "Cancer."

Head and neck cancer refers to malignant tumors that occur in various parts of the head and neck, excluding tumors of the brain and eyes. It can occur in the face, nose, neck, oral cavity, pharynx, salivary glands, and thyroid. Head and neck cancer is the seventh most common cancer globally, with increased incidence particularly in middle- and low-income countries.

The research team surveyed 9,548 head and neck cancer patients and 15,783 people without cancer about their coffee consumption, including whether it was caffeinated, as well as their tea consumption, to investigate the relationship between head and neck cancer, coffee, and tea consumption.

The results showed that individuals who drank more than 4 cups of caffeinated coffee a day had a 17% lower risk of developing head and neck cancer compared to those who did not drink coffee. The risk of oral cancer decreased by 30%, and the risk of throat cancer decreased by 22%. Consuming 3 to 4 cups of caffeinated coffee a day reduced the risk of developing hypopharyngeal cancer, a type of cancer that occurs below the pharynx, by 41%.

Decaffeinated coffee also showed similar effects. People who drank decaffeinated coffee had a 25% lower risk of developing oral cancer. However, tea showed less clear effects compared to coffee. Drinking less than 1 cup of tea a day reduced the risk of head and neck cancer by 9%, and the risk of hypopharyngeal cancer decreased by 27%. In contrast, a tendency was observed where drinking more than 1 cup of tea a day increased the risk of laryngeal cancer by 38%.

The researchers noted, "Perhaps the physiologically active compounds other than caffeine could contribute to the potential anti-cancer effects of coffee and tea." They speculated that the reason for the increased risk of laryngeal cancer with tea consumption could be related to the potential increase in the risk of gastroesophageal reflux disease.

Yuan-Chin Amy Lee, a professor at the University of Utah, who led the study, said, "We confirmed the effects of coffee and tea consumption on head and neck cancer and other cancers, and the observational results also included the positive effects of decaffeinated coffee." However, she added that due to the complexity of coffee and tea consumption habits, further research is needed to analyze their links to cancer risk.

Tom Sanders, an honorary professor in the Department of Nutrition at King's College London, noted at the Science Media Centre, a scientific press support organization, that "it is difficult to completely eliminate the confounding effects of substances like tobacco or alcohol in statistical analyses." He added that individuals who consume a lot of coffee and tea are likely to avoid harmful behaviors such as drinking and smoking, and thus, their risk of cancer may be lower.

Reference materials

Cancer (2024), DOI: https://doi.org/10.1002/cncr.35620