Studies on the association between heavy coffee consumption and risk of less frequently diagnosed cancers are scarce. We aimed to quantify the association between filtered, boiled, and total coffee consumption and the risk of bladder, esophageal, kidney, pancreatic, and stomach cancers. We used data from the Norwegian Women and Cancer Study and the Northern Sweden Health and Disease Study. Information on coffee consumption was available for 193,439 participants. We used multivariable Cox proportional hazards models to calculate hazard ratios (HR) with 95% confidence intervals (CI) for the investigated cancer sites by category of total, filtered, and boiled coffee consumption. Heavy filtered coffee consumers (≥ 4 cups/day) had a multivariable adjusted HR of 0.74 of being diagnosed with pancreatic cancer (95% CI 0.57-0.95) when compared with light filtered coffee consumers (≤ 1 cup/day). We did not observe significant associations between total or boiled coffee consumption and any of the investigated cancer sites, neither in the entire study sample nor in analyses stratified by sex. We found an increased risk of bladder cancer among never smokers who were heavy filtered or total coffee consumers, and an increased risk of stomach cancer in never smokers who were heavy boiled coffee consumers. Our data suggest that increased filtered coffee consumption might reduce the risk of pancreatic cancer. We did not find evidence of an association between coffee consumption and the risk of esophageal or kidney cancer. The increased risk of bladder and stomach cancer was confined to never smokers.
European journal of epidemiology. 2018 Feb 23 [Epub ahead of print]
Marko Lukic, Lena Maria Nilsson, Guri Skeie, Bernt Lindahl, Tonje Braaten
Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsö, Norway. ., Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden., Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsö, Norway., Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden.