title: Greater intake of fruit and vegetables is associated with lower risk of nasopharyngeal carcinoma in Chinese adults: a case-control study.
abstract: OBJECTIVE
  The effect of fruit and vegetable intake on the risk of nasopharyngeal carcinoma (NPC) remains uncertain due to limited published evidence. We performed a matched case-control study to investigate the relationship between the intake of fruit and vegetables and the risk of NPC.
  
  
  METHODS
  Between July 2009 and March 2011, 600 (448 male, 152 female), NPC incident cases from a single hospital in Guangzhou, Guangdong Province, China, a high-incidence area, were enrolled in the study. 600 controls, matched by gender, age (± 3 years) and household type (urban/rural) were also enrolled. Face-to-face interviews were used to collect habitual dietary intakes and information on various covariates.
  
  
  RESULTS
  Multivariate conditional logistic regression analyses showed significant, dose-dependent inverse associations between the intake of vegetables, fruit or a combination of the two and the risk of NPC, even after adjustments for social-economic status, body mass index, dietary factors and other potential covariates. The adjusted odds ratios (95% confidence intervals) for NPC in the top quartile of vegetable intake, fruit intake or a combination of the two, as compared to the lowest quartile, were 0.33 (0.22-0.50), 0.70 (0.47-1.04) and 0.37 (0.25-0.55), respectively. Dark green leafy vegetables, carrots, peppers and tomatoes, citrus fruit and pome fruit showed much more pronounced benefits with regards to NPC than other types of fruit and vegetables. Interaction analyses demonstrated that the effects of total combined vegetable and fruit intake were much more significant in subjects with a higher education level (p interaction: 0.027), and the benefits of fruit were observed in males, but not in females (p interaction: 0.088).
  
  
  CONCLUSIONS
  Our findings suggest that a greater consumption of fruit and vegetables may lower the risk of NPC in Chinese adults.
authors.affiliation: Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, People's Republic of China.
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Liu
authors.forename: Jun-Jin
authors.initials: JJ
authors.lastname: Dai
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Xu
authors.forename: Yun-Kai
authors.initials: YK
authors.lastname: Lu
authors.forename: Yu-Ying
authors.initials: YY
authors.lastname: Fan
authors.forename: Xing-Lan
authors.initials: XL
authors.lastname: Zhang
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Zhang
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Chen
mesh_terms: D000328:Adult; D044466:Asian People; D002277:Carcinoma; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004032:Diet; D005260:Female; D005638:Fruit; D006801:Humans; D008297:Male; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D014675:Vegetables