Consumption of vegetables and fruit and the risk of bladder cancer in the European Prospective Investigation into Cancer and Nutrition.
Büchner FL., Bueno-de-Mesquita HB., Ros MM., Kampman E., Egevad L., Overvad K., Raaschou-Nielsen O., Tjønneland A., Roswall N., Clavel-Chapelon F., Boutron-Ruault MC., Touillaud M., Chang-Claude J., Kaaks R., Boeing H., Weikert S., Trichopoulou A., Lagiou P., Trichopoulos D., Palli D., Sieri S., Vineis P., Tumino R., Panico S., Vrieling A., Peeters PH., van Gils CH., Lund E., Gram IT., Engeset D., Martinez C., Gonzalez CA., Larrañaga N., Ardanaz E., Navarro C., Rodríguez L., Manjer J., Ehrnström RA., Hallmans G., Ljungberg B., Allen NE., Roddam AW., Bingham S., Khaw KT., Slimani N., Boffetta P., Jenab M., Mouw T., Michaud DS., Kiemeney LA., Riboli E.
Previous epidemiologic studies found inconsistent associations between vegetables and fruit consumption and the risk of bladder cancer. We therefore investigated the association between vegetable and fruit consumption and the risk of bladder cancer among participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Data on food consumption and complete follow-up for cancer occurrence was available for a total of 478,533 participants, who were recruited in 10 European countries. Estimates of rate ratios were obtained by Cox proportional hazard models, stratified by age at recruitment, gender and study centre, and adjusted for total energy intake, smoking status, duration of smoking and lifetime intensity of smoking. A calibration study in a subsample was used to control for dietary measurement errors. After a mean follow-up of 8.7 years, 1015 participants were newly diagnosed with bladder cancer. Increments of 100 g/day in fruit and vegetable consumption combined did not affect bladder cancer risk (i.e., calibrated HR = 0.98; 95%CI: 0.95-1.01). Borderline statistically significant lower bladder cancer risks were found among never smokers with increased consumption of fruit and vegetables combined (HR = 0.94 95%CI: 0.87-1.00 with increments of 100 g/day; calibrated HR = 0.92 95%CI 0.79-1.06) and increased consumption of apples and pears (hard fruit; calibrated HR = 0.90 95%CI: 0.82-0.98 with increments of 25 g/day). For none of the associations a statistically significant interaction with smoking status was found. Our findings do not support an effect of fruit and vegetable consumption, combined or separately, on bladder cancer risk.