title: Associations between dietary intakes of iron, copper and zinc with risk of type 2 diabetes mellitus: A large population-based prospective cohort study.
abstract: Abnormal homeostasis of iron, copper and zinc has been included in the pathogenesis of type 2 diabetes mellitus (T2DM). However, the evidence of associations between dietary intakes of these elements and T2DM is limited. We thought to examine the association between dietary intakes of iron, copper and zinc with risk of T2DM in Japanese population.
  
  
  
  A prospective study encompassing 16,160 healthy Japanese men and women aged 40-65 years in whom the associations between dietary intakes of iron, copper and zinc, determined by a validated self-administered food frequency questionnaire, with risk of 5-year cumulative incidence of validated physician-diagnosed T2DM, were evaluated by logistic regression model.
  
  
  
  We ascertained 396 self-reported new cases of diabetes within 5-year period. Dietary intakes of iron (total and nonheme but not heme iron) and copper were positively associated with risk of T2DM; the multivariable OR in the highest versus lowest quartiles of intakes were 1.32 (1.04, 1.70; P-trend = 0.03) and 1.55 (1.13, 2.02; P-trend = 0.003), respectively. These associations were more evident in the high risk group; older, overweight, smokers and those with family history of diabetes. The dietary intake of zinc was inversely associated with risk of T2DM; the multivariable OR was 0.64 (0.54, 1.00; P-trend = 0.003), and such association was evident among younger subjects (age 40-55 years) only.
  
  
  
  Dietary intakes of iron and copper were associated with a higher risk, while dietary intake of zinc was associated with a reduced risk of T2DM in Japanese population.
authors.affiliation: Public Health, Department of Social Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan; Public Health and Community Medicine Department, Faculty of Medicine, Minia University, Minia, Egypt.
authors.forename: Ehab S
authors.initials: ES
authors.lastname: Eshak
authors.affiliation: Public Health, Department of Social Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan. Electronic address: iso@pbhel.med.osaka-u.ac.jp.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.affiliation: Department of Public Health, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Koutatsu
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Department of Cardiovascular Disease Prevention, Osaka Center for Cancer and Cardiovascular Disease Prevention, Osaka, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Muraki
authors.affiliation: Public Health, Department of Social Medicine, Graduate School of Medicine, Hokkaido University, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Tamakoshi
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003300:Copper / Q000008:administration & dosage*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D015930:Diet Records; D005260:Female; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D015032:Zinc / Q000008:administration & dosage*
chemical_list: D019266:Iron, Dietary; D003300:Copper; D015032:Zinc
keywords: Cohort study; Copper; Iron; Japanese; Type 2 diabetes mellitus; Zinc