Epidemiologic studies suggest that a high intake of fruits and vegetables is associated with decreased risk of cancers of
the upper aero-digestive tract. We studied data from 345,904 subjects of the prospective European Investigation into Cancer
and Nutrition (EPIC) recruited in seven European countries, who had completed a dietary questionnaire in 1992–1998. During
2,182,560 person years of observation 352 histologically verified incident squamous cell cancer (SCC) cases (255 males; 97
females) of the oral cavity, pharynx, larynx, and esophagus were identified. Linear and restricted cubic spline Cox regressions
were fitted on variables of intake of fruits and vegetables and adjusted for potential confounders. We observed a significant
inverse association with combined total fruits and vegetables intake (estimated relative risk (RR) = 0.91; 95% confidence
interval (95% CI) 0.83–1.00 per 80 g/d of consumption), and nearly significant inverse associations in separate analyses with
total fruits and total vegetables intake (RR: 0.97 (95% CI: 0.92–1.02) and RR = 0.89 (95% CI: 0.78–1.02) per 40 g/d of consumption).
Overall, vegetable subgroups were not related to risk with the exception of intake of root vegetables in men. Restricted cubic
spline regression did not improve the linear model fits except for total fruits and vegetables and total fruits with a significant
decrease in risk at low intake levels (<120 g/d) for fruits. Dietary recommendations should consider the potential benefit
of increasing fruits and vegetables consumption for reducing the risk of cancers of the upper aero-digestive tract, particularly
at low intake.
Keywords Upper aero-digestive cancer - Fruits and vegetables - Root vegetables - Prospective study - EPIC - Relative risk
Department of Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbrücke