Validation of an FFQ to assess antioxidant intake in overweight postmenopausal women

Abstract

Objective: To validate an FFQ to assess antioxidant intake in overweight postmenopausal women. Design: A seventy-four-item antioxidant 1-month FFQ was developed based on major antioxidant sources in the American diet. Forty overweight postmenopausal women participated in a 9-month observational study and completed four sets of FFQ and 7 d food record (7dFR) every 3 months. Twelve-hour fasting blood was collected for plasma antioxidant measurement at the first visit. Setting: Connecticut, USA. Subjects: Forty overweight postmenopausal women. Results: Spearman correlation coefficients of 1-month antioxidant intake estimated from the first set of FFQ and 7dFR ranged from 0?34 to 0?87, except for g-tocopherol.The proportion of participants categorized into the extremely opposite tertiles averaged 7 %. Significant correlations were observed for diet-plasma vitamin C, a-tocopherol and carotenoids (P , 0?05). No time effect was observed on the dietary antioxidant intakes estimated from four 7dFR and four FFQ. Dietary antioxidants estimated from averaged four 7dFR showed moderate to high correlation with those estimated from averaged four FFQ and from each FFQ collected every 3 months. Bland-Altman plots did not show any systematic bias. Averaged misclassifications were below 10 % between these two instruments. Conclusions: These findings attested a reasonable validity and a good acceptance of this 1-month FFQ in assessing both short-term and long-term diverse antioxidant intakes in these overweight postmenopausal women. The use of this FFQ in associating antioxidant intake with disease risk needs further investigation.

Development and Validation of a Short Food Frequency Questionnaire to Measure Dietary Intake of a Selection of Immune-Modulating Nutrients in Patients with Established Peripheral Arterial Disease

“…However, this second study only had 40 participants which may not be sufficient to accurately calculate the LOA [20]. Interestingly, despite the clinically wide LOA in the present study and literature, all had adequate agreement on a population level [36,37]. This indicates that the wide LOA obtained in the current study are not abnormal, therefore changes to the FFQ are not required at this stage.…”

“…Previous studies have also observed wide LOA for vitamin C. In a study of 238 participants, the LOA ranged from −121.81 to 178.89 mg, with a bias of 28.54 mg [36]. Another study reported LOA of −110 to 120 mg, with a bias of 5 mg [37]. However, this second study only had 40 participants which may not be sufficient to accurately calculate the LOA [20].…”

Scientific Opinion on Dietary Reference Values for vitamin E as α‐tocopherol

“…Published data suggest that mean α-tocopherol intakes in adults in some European countries (Finland, Sweden) (Amcoff et al, 2012;Helldán et al, 2013) are higher than those observed in the USA, where γ-tocopherol intakes are generally reported to be higher than in the EU (Gao et al, 2004;Maras et al, 2004;Dixon et al, 2006;Mahabir et al, 2008;Signorello et al, 2010;Yang et al, 2014a;Yang et al, 2014b).…”

Twenty‐five years of total antioxidant capacity measurement of foods and biological fluids: merits and limitations

“…The TAC values from diet and diet and supplements were highly correlated between the FFQ and 30‐day food records, whereas neither TAC from diet, nor TAC from diet and supplements was correlated with plasma TAC level. The feasibility in assessing long‐term antioxidant intake of the FFQ was later evaluated in 40 overweight postmenopausal women who participated in a 9‐month observational study and completed four sets of FFQ and 7‐day food record every 3 months . No significant seasonal variation of antioxidant intakes supports the applicability of this 1‐month FFQ with respect to capturing a usual dietary antioxidant pattern for these overweight postmenopausal women.…”