title: Development and validation of a food frequency questionnaire for the assessment of dietary total antioxidant capacity.
abstract: The total antioxidant capacity (TAC) of the diet may be an important tool to monitor the protective effect of plant foods in epidemiological studies. We developed a semi-quantitative FFQ for the assessment of dietary TAC by 3 different assays, i.e., Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP) and ferric reducing-antioxidant power (FRAP). The FFQ consists of 53 questions about the major sources of dietary TAC in Northern Italy and was validated against a 3-d weighed food record (3D-WR) in 285 individuals (159 males and 126 females) aged 35-88 y and living in the province of Parma (Italy). Plasma TAC was also evaluated in a subgroup of subjects using the TEAC and FRAP assays. The FFQ was associated with 3D-WR (quadratic-weighted kappa = 0.49 for TEAC, 0.53 for TRAP, and 0.49 for FRAP; P < 0.0001) and proved reasonably accurate to classify individuals into quartiles of TAC intake. The FFQ had a good repeatability when readministered after 1 y in 55 subjects (quadratic-weighted kappa for intertertile agreement = 0.66 for TEAC, 0.70 for TRAP and 0.68 for FRAP; P < 0.0001). With both dietary instruments, the main contributors to TAC intake were coffee and tea in women and alcoholic beverages in men, followed by fruits and vegetables in both sexes. Plasma TAC and dietary TAC were not associated. In conclusion, our FFQ has the potential for being used to rank subjects on the basis of their antioxidant intake as determined by dietary TAC in large epidemiological studies. The FFQ should be validated in external populations before being used for research purposes.
authors.affiliation: Department of Public Health, University of Parma, Parma, Italy. nicoletta.pelllegrini@unipr.it
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Pellegrini
authors.forename: Sara
authors.initials: S
authors.lastname: Salvatore
authors.forename: Silvia
authors.initials: S
authors.lastname: Valtueña
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bedogni
authors.forename: Marisa
authors.initials: M
authors.lastname: Porrini
authors.forename: Valeria
authors.initials: V
authors.lastname: Pala
authors.forename: Daniele
authors.initials: D
authors.lastname: Del Rio
authors.forename: Sabina
authors.initials: S
authors.lastname: Sieri
authors.forename: Cristiana
authors.initials: C
authors.lastname: Miglio
authors.forename: Vittorio
authors.initials: V
authors.lastname: Krogh
authors.forename: Ivana
authors.initials: I
authors.lastname: Zavaroni
authors.forename: Furio
authors.initials: F
authors.lastname: Brighenti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000493:pharmacokinetics*; D015992:Body Mass Index; D015930:Diet Records; D005247:Feeding Behavior; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D000975:Antioxidants