Fruit and Vegetable Consumption and Cancer in Canada

This study examines the association between fruit and vegetable intake and the risk of various cancers. Mailed questionnaires were completed by 19,732 incident, histologically confirmed cases of cancer of the stomach, colon, rectum, pancreas, lung, breast, ovary, prostate, testis, kidney, bladder, brain, non-Hodgkin's lymphomas and leukaemia, and 5039 population controls between 1994 and 1997 in 8 Canadian provinces. Measurements included information on socio-economic status, lifestyle habits, and diet. A 69-item food frequency questionnaire provided data on eating habits two years before data collection. Odds ratios and 95% confidence intervals were derived through unconditional logistic regression. High fruit intake was inversely associated with the risk of stomach, lung, kidney, and bladder cancer in women. Total vegetable intake significantly reduced the risk of lung and kidney cancer in men and pancreas cancer in women. High intake of yellow-orange vegetables was associated with 30-40% reductions in risk of stomach cancer and lung cancer in both genders, and cancers of the pancreas and kidney in women. A significant inverse association between intake of dark-green vegetables and cancers of pancreas, kidney, and brain was observed in women. Intake of cruciferous vegetable was inversely related to the risk of stomach, kidney, and brain cancer in women. No association was found for cancers of the colon, rectum, female breast, ovary, prostate, testis, non-Hodgkin's lymphomas, and leukaemia. The present findings add further evidence that fruit and vegetables, specifically yellow, orange, dark-green, and cruciferous vegetables may reduce the risk of some cancers.