Coffee and green tea consumption is associated with upper aero digestive tract cancer in Japan,

I Oze et al, 2013, Coffee and green tea consumption is associated with upper aero digestive tract cancer in Japan, Int Journal of Cancer

The impact of coffee and green tea consumption on upper aerodigestive tract (UADT) cancer risk has not been established. Evaluation of the possible anti-carcinogenic properties of their ingredients is confounded by the potential increase in risk due to the high temperatures at which these beverages are generally consumed. We conducted a case-control study to evaluate the association between coffee and tea consumption and the risk of UADT cancer. The study enrolled 961 patients with UADT cancer and 2,883 non-cancer outpatients who visited Aichi Cancer Center between 2001 and 2005. Information on coffee and green tea consumption and other lifestyle factors was collected via a self-administered questionnaire. Consumption of 3 or more cups of coffee per day had a significant inverse association with UADT cancer (OR 0.73, 95% CI 0.55-0.96). In contrast, consumption of three or more cups of green tea per day had a significant positive association with UADT cancer (OR 1.39, 95% CI 1.13-1.70). These associations were evident for head and neck cancer but not for esophageal cancer. The association of coffee consumption with head and neck cancer was observed only among never smokers and alcohol drinkers. Similarly, the association of green tea consumption was observed among never smokers and never alcohol drinkers. No change in these associations was seen on stratification by each confounding factors. These findings suggest that consumption of coffee might be associated with a decreased risk of UADT cancer, whereas that of green tea might be associated with an increased risk.