Publication
Dietary flavonoids and flavonoid-rich foods: validity and reproducibility of FFQ-derived intake estimates
Publisher:
Cambridge University Press (CUP)
Date:
23-07-2020
DOI:
10.1017/S1368980020001627
Abstract: To evaluate the validity and reproducibility of a 152-item semi-quantitative FFQ (SFFQ) for estimating flavonoid intakes. Over a 1-year period, participants completed two SFFQ and two weighed 7-d dietary records (7DDR). Flavonoid intakes from the SFFQ were estimated separately using Harvard (SFFQ Harvard ) and Phenol-Explorer (SFFQ PE ) food composition databases. 7DDR flavonoid intakes were derived using the Phenol-Explorer database (7DDR PE ). Validity was assessed using Spearman’s rank correlation coefficients deattenuated for random measurement error ( r s ), and reproducibility was assessed using rank intraclass correlation coefficients. This validation study included primarily participants from two large observational cohort studies. Six hundred forty-one men and 724 women. When compared with two 7DDR PE , the validity of total flavonoid intake assessed by SFFQ PE was high for both men and women ( r s = 0·77 and r s = 0·74, respectively). The r s for flavonoid subclasses ranged from 0·47 for flavones to 0·78 for anthocyanins in men and from 0·46 for flavonols to 0·77 for anthocyanins in women. We observed similarly moderate (0·4–0·7) to high (≥0·7) validity when using SFFQ Harvard estimates, except for flavones Harvard ( r s = 0·25 for men and r s = 0·19 for women). The SFFQ demonstrated high reproducibility for total flavonoid and flavonoid subclass intake estimates when using either food composition database. The intraclass correlation coefficients ranged from 0·69 (flavonols PE ) to 0·80 (proanthocyanidins PE ) in men and from 0·67 (flavonols PE ) to 0·77 (flavan-3-ol monomers Harvard ) in women. SFFQ-derived intakes of total flavonoids and flavonoid subclasses (except for flavones) are valid and reproducible for both men and women.