Intakes of fruits, vegetables, vitamins A, C, and E, and carotenoids and risk of renal cell cancer.

A168

Background: Fruits and vegetables rich in antioxidants have been proposed to reduce the risk of renal cell cancer. However, few prospective studies have examined intake of fruits, vegetables, and antioxidant vitamins in relation to risk of renal cell cancer. Methods: We prospectively examined the associations between the intakes of fruits, vegetables, vitamins A, C, and E, and carotenoids and risk of renal cell cancer in women and men. We followed 88,759 women in the Nurses' Health Study from 1980 to 2000, and 47,828 men in the Health Professionals Follow-up Study from 1986 to 2000. We assessed dietary intake every two to four years using a validated semi-quantitative food frequency questionnaire. The Cox proportional hazards model was used to estimate study-specific multivariate relative risks (RRs), which were pooled using a random effects model. Results: A total of 248 (132 women and 116 men) incident renal cell cancer cases were ascertained during 2,316,525 person-years of follow-up. Consumption of fruits and vegetables was associated with a decreased risk of renal cell cancer in men (multivariate RR = 0.45; 95% CI = 0.25-0.81, for 6 or greater servings of fruit and vegetable intake per day versus <3 servings per day; P-value, test for trend = 0.02), but not in women (multivariate RR = 1.17; 95% CI = 0.66-2.07, for the same contrast; P-value, test for trend = 0.25; P-value, test for between-studies heterogeneity = 0.02). Intakes of vitamins A and C from food and carotenoids were inversely associated with the risk of renal cell cancer in men only, but we cannot exclude the possibility that this was due to other factors in fruit and vegetables. No clear association was observed for vitamin E in women or men. Conclusions: Fruit and vegetable consumption may reduce the risk of renal cell cancer in men.