title: Fruit, vegetables, fibre and micronutrients and risk of US renal cell carcinoma.
abstract: The association between renal cell cancer (RCC) and intake of fruit, vegetables and nutrients was examined in a population-based case-control study of 323 cases and 1827 controls; dietary intake was obtained using a mailed questionnaire. Cancer risks were estimated by OR and 95 % CI, adjusting for age, sex, smoking, obesity, hypertension, proxy status, alcohol consumption and dietary fat intake and energy. Intake of vegetables was associated with a decreased risk of RCC (OR 0·5; 95 % CI 0·3, 0·7; P               trend = 0·002), (top compared to the bottom quartile of intake). When intake of individual nutrients was investigated, vegetable fibre intake was associated with decreased risks (OR 0·4; 95 % CI 0·2, 0·6; P < 0·001), but this was not the case with fruit fibre (OR 0·7; 95 % CI 0·4, 1·1) or grain fibre (OR 1·0; 95 % CI 0·6, 1·5). β-Cryptoxanthin and lycopene were also associated with decreased risks, but when both were included in a mutually adjusted backwards stepwise regression model, only β-cryptoxanthin remained significant (OR 0·5; 95 % CI 0·3, 0·8). When other micronutrients and types of fibre were investigated together, only vegetable fibre and β-cryptoxanthin had significant trends (P < 0·01) (OR 0·6; 95 % CI 0·3, 0·9) (OR 0·5; 95 % CI 0·3, 0·9), respectively. These findings were stronger in those aged over 65 years (P               interaction = 0·001). Among non-smokers, low intake of cruciferous vegetables and fruit fibre was also associated with increased risk of RCC (P               interaction = 0·03); similar inverse associations were found for β-cryptoxanthin, lycopene and vitamin C. When nutrients were mutually adjusted by backwards regression in these subgroups, only β-cryptoxanthin remained associated with lower RCC risk. These findings deserve further investigation in ongoing prospective studies when sample size becomes sufficient.
authors.affiliation: Department of Behavioural and Social Sciences, Faculty of Health Sciences, University of Sydney, Sydney, New South Wales, Australia. kaye.brock@sydney.edu.au
authors.forename: Kaye E
authors.initials: KE
authors.lastname: Brock
authors.forename: Liang
authors.initials: L
authors.lastname: Ke
authors.forename: Gloria
authors.initials: G
authors.lastname: Gridley
authors.forename: Brian C-H
authors.initials: BC
authors.lastname: Chiu
authors.forename: Abby G
authors.initials: AG
authors.lastname: Ershow
authors.forename: Charles F
authors.initials: CF
authors.lastname: Lynch
authors.forename: Barry I
authors.initials: BI
authors.lastname: Graubard
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Cantor
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D016022:Case-Control Studies; D065366:Cryptoxanthins; D004032:Diet / Q000009:adverse effects*; D004043:Dietary Fiber / Q000008:administration & dosage* / Q000627:therapeutic use; D002523:Edible Grain / Q000737:chemistry; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D018977:Micronutrients / Q000008:administration & dosage*; D008875:Middle Aged; D009749:Nutrition Surveys; D012042:Registries; D012307:Risk Factors; D014675:Vegetables / Q000737:chemistry; D024341:Xanthophylls / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D065366:Cryptoxanthins; D004043:Dietary Fiber; D018977:Micronutrients; D024341:Xanthophylls