Mate drinking, alcohol, tobacco, diet, and esophageal cancer in Uruguay.

A case-control study was conducted in Uruguay to investigate the role of mate drinking, alcohol, tobacco, and certain dietary factors in the etiology of esophageal cancer. The study included 261 patients with squamous cell carcinoma of the esophagus and 522 hospital controls matched by sex and age. A strong association with a clear dose-response relationship was observed with the amount of mate drunk daily and duration of the habit. The relative risk for those drinking over 2.5 liters of mate per day was 12.2 (95% confidence interval, 3.8-39.6) after adjusting for the effects of age, area of residence, alcohol, and tobacco. Strong associations were also observed with tobacco smoking and alcohol drinking which appear to act in a multiplicative way. The relative risk for those who smoke and drink heavily compared to that of light smokers and drinkers was 22.6. The risk associated with black tobacco was about three times higher than that associated with blond tobacco. A clear protective effect was found for the consumption of fruits and vegetables but a dose-response relationship was present only for fruits. Finally, an increased risk was also found for those eating barbecued meat daily.