title: Dietary total antioxidant capacity is related to glucose tolerance in older people: the Hertfordshire Cohort Study.
abstract: OBJECTIVE
  Dietary antioxidants may play a protective role in the aetiology of type 2 diabetes. However, observational studies that examine the relationship between the antioxidant capacity of the diet and glucose metabolism are limited, particularly in older people. We aimed to examine the relationships between dietary total antioxidant capacity (TAC) and markers of glucose metabolism among 1441 men and 1253 women aged 59-73 years who participated in the Hertfordshire Cohort Study, UK.
  
  
  RESULTS
  Diet was assessed by food frequency questionnaire. Dietary TAC was estimated using published databases of TAC measured by four different assays: oxygen radical absorbance capacity (ORAC), ferric-reducing ability of plasma (FRAP), total radical-trapping antioxidant parameter (TRAP) and trolox equivalent antioxidant capacity (TEAC). Fasting and 120-min plasma glucose and insulin concentrations were measured during a standard 75-g oral glucose tolerance test. In men, dietary TAC estimated by all four assays was inversely associated with fasting insulin concentration and homoeostasis model assessment of insulin resistance (HOMA-IR); with the exception of ORAC, dietary TAC was also inversely related to 120-min glucose concentration. There were no associations with fasting glucose or 120-min insulin concentrations. In women, with the exception of the association between ORAC and 120-min insulin concentration, dietary TAC estimated by all assays showed consistent inverse associations with fasting and 120-min glucose and insulin concentrations and HOMA-IR. These associations were more marked among women with BMI ≥ 30 kg/m(2).
  
  
  CONCLUSIONS
  These findings suggest dietary TAC may have important protective effects on glucose tolerance, especially in older obese women.
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK; Department of Social and Preventive Epidemiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okubo
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: H E
authors.initials: HE
authors.lastname: Syddall
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: D I W
authors.initials: DI
authors.lastname: Phillips
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: A A
authors.initials: AA
authors.lastname: Sayer
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: E M
authors.initials: EM
authors.lastname: Dennison
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: C
authors.initials: C
authors.lastname: Cooper
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK. Electronic address: smr@mrc.soton.ac.uk.
authors.forename: S M
authors.initials: SM
authors.lastname: Robinson
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001835:Body Weight; D003924:Diabetes Mellitus, Type 2; D004032:Diet; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000097:blood*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D008019:Life Style; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015596:Nutrition Assessment; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D006113:United Kingdom
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D007328:Insulin
keywords: Diet; Epidemiology; Glucose tolerance; Total antioxidant capacity