Abstract
Purpose::
The macular pigment in the central human retina is composed of xanthophylls, primarily lutein and zeaxanthin, obtained in the diet. Dietary intake of lutein and zeaxanthin, for most individuals, is linearly related to concentrations of macular pigment. The objective of the current project was to compare xanthophyll intakes calculated with two detailed food frequency questionnaires (FFQ) and two short questionnaires assessing fruit and vegetable intake with tissue concentrations of lutein and zeaxanthin.
Methods::
Dietary intake of xanthophylls was estimated in one-hundred adults using standardized FFQs from the Block Dietary Data Systems (BFFQ) and the Fred Hutchinson Cancer Research Center (FHFFQ). Fruit and vegetable intake was quantified with two fruit and vegetable screeners: the Block Fruit and Vegetable Screener (BFV) and an unpublished screener (TFV). Fasting serum concentrations of lutein and zeaxanthin were measured using high-performance liquid chromatography. Retinal lutein and zeaxanthin concentrations were measured as macular pigment optical density (MPOD) with heterochromatic flicker photometry.
Results::
Mean, daily intake of lutein and zeaxanthin estimated by the BFFQ (2.22mg/d ±0.15) significantly differed (p = 0.007) from daily intake estimated by the FHFFQ (1.73mg/d ±0.09). This relationship was also observed when intakes were adjusted for caloric intake. Neither serum lutein and zeaxanthin nor MPOD was related to BFFQ estimates of dietary intake. In contrast, dietary intake assessed with the FHFFQ was significantly related to serum lutein and zeaxanthin (p = 0.009), and MPOD at 30' (p = 0.019), 60' (p = 0.02) and 120' (p = 0.04) eccentricity. MPOD at 30' eccentricity was related to fruit and vegetable intake assessed with the BFV (p = 0.002) and TFV (p = 0.045), but only the TFV was related to serum lutein and zeaxanthin (p = 0.032).
Conclusions::
Tissue concentrations of lutein and zeaxanthin were significantly related to dietary intake assessed by one, but not both, FFQs. Fruit and vegetable intake assessed by both screeners was correlated with serum lutein and zeaxanthin, but only one was correlated with MPOD.
Keywords: macular pigment • carotenoids/carotenoid binding proteins • nutritional factors