Development and validation of a brief food frequency questionnaire for dietary lutein and zeaxanthin intake assessment in Italian women

Abstract

There is increasing evidence that higher intakes of carotenoids could protect against oxidative and light damage in premature infants and may promote other health benefits in both mothers during pregnancy and lactation and in newborn infants. To develop and validate a brief quantitative food frequency questionnaire (FFQ) aimed at assessing lutein and zeaxanthin intake in women. In this cross-sectional study, estimates of lutein and zeaxanthin intake from the FFQ were compared with a 7-day dietary record and with plasma concentrations of these carotenoids. This primary care study was conducted in Pavia, Italy. Subjects were all female volunteers, aged 20-25 years (mean age 22.7 +/- 2.1 years), university students. Of the 110 women initially recruited, 87 completed diet questionnaires and donated a blood sample. Dietary intake was assessed by the FFQ by interview and 7-day dietary records chosen as a reference standard, using photographic estimations of portion sizes. Plasma concentrations of lutein and zeaxanthin were measured by HPLC. Pearson's correlation coefficient and Bland Altman Regression analysis were used. Mean dietary lutein and zeaxanthin intakes were 1,107 +/- 113 microg/day from the FFQ questionnaire and 1,083 +/- 116 microg/day from the 7 day dietary records. The mean difference in intake assessed by the two methods (-24.5 +/- 38.3 microg/day) did not differ significantly from zero. Dietary intake of lutein and zeaxanthin measured with the FFQ and plasma nutrient concentration among this sample were significantly correlated (r = 0.76, P < 0.0001). Mean plasma lutein and zeaxanthin concentrations were 0.33 +/- 0.09 micromol/l. This FFQ could be used to assess lutein and zeaxanthin intake in adult women.