title: Association between dietary factors and breast cancer risk among Chinese females: systematic review and meta-analysis.
abstract: BACKGROUND
  Evidence for associations between dietary factors and breast cancer risk is inconclusive among Chinese females. To evaluate this question, we conducted a systematic review of relevant case-control and cohort studies.
  
  
  METHODS
  Studies were systematically searched among 5 English databases (PudMed, ScienceDirect, Wiley, Clinicaltrials.gov, and Cochrane) and 3 Chinese databases (CNKI, WanFang, and VIP) until November 2012. Random effects models were used to estimate summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs).
  
  
  RESULTS
  Thirty one case-control studies and two cohort studies involving 9,299 cases and 11,413 controls were included. Consumption of both soy and fruit was significantly associated with decreased risk of breast cancer, with summary ORs of 0.65 (95% CIs: 0.43-0.99; I2=88.9%, P<0.001; N=13) and 0.66 (95% CIs: 0.47-0.91; I2=76.7%, P<0.001; N=7), respectively. Consumption of fat was significantly associated with increased risk of breast cancer (OR=1.36; 95% CIs: 1.13-1.63; I2=47.9%, P=0.088; N=6). There was non- significant association between consumption of vegetables and breast cancer risk (OR=0.72; 95% CIs: 0.51-1.02; I2= 74.4%, P<0.001; N=9). However, sensitivity analysis based on adjusted ORs showed decreased risk of breast cancer was also associated with consumption of vegetables (OR=0.49; 95% CIs: 0.30-0.67).
  
  
  CONCLUSIONS
  Both soy food and fruit are significantly associated with decreased risk of breast cancer among Chinese females, and vegetables also seems to be protective while dietary fatexerts a promoting influence.
authors.affiliation: Department of Epidemiology and Biostatistics, Tianjin Medical University Cancer Hospital and Institute, National Clinical Research Center for Cancer, Tianjin, China E-mail : chenkexin1963@yahoo.com.
authors.forename: Xue-Ou
authors.initials: XO
authors.lastname: Liu
authors.forename: Yu-Bei
authors.initials: YB
authors.lastname: Huang
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: Chuan
authors.initials: C
authors.lastname: Chen
authors.forename: Ye
authors.initials: Y
authors.lastname: Yan
authors.forename: Hong-Ji
authors.initials: HJ
authors.lastname: Dai
authors.forename: Feng-Ju
authors.initials: FJ
authors.lastname: Song
authors.forename: Yao-Gang
authors.initials: YG
authors.lastname: Wang
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Wang
authors.forename: Ke-Xin
authors.initials: KX
authors.lastname: Chen
mesh_terms: D001943:Breast Neoplasms / Q000178:diet therapy* / Q000517:prevention & control; D002681:China; D004041:Dietary Fats / Q000009:adverse effects*; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006801:Humans; D012307:Risk Factors; D045730:Soy Foods
chemical_list: D004041:Dietary Fats