The Effect of Modified Eggs and an Egg-Yolk Based Beverage on Serum Lutein and Zeaxanthin Concentrations and Macular Pigment Optical Density: Results from a Randomized Trial

Elton R Kelly,Guido R M M Haenen,Jogchum Plat,Aize Kijlstra,Tos T J M Berendschot,Robert K Hills

doi:10.1371/journal.pone.0092659

Elton R Kelly, Guido R M M Haenen + Show 4 more

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https://doi.org/10.1371/journal.pone.0092659

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Journal: PloS one	Publication Date: Mar 27, 2014
Citations: 73	License type: CC BY 4.0

Affiliation: Maastricht University

Abstract

Increasing evidence suggests a beneficial effect of lutein and zeaxanthin on the progression of age-related macular degeneration. The aim of this study was to investigate the effect of lutein or zeaxanthin enriched eggs or a lutein enriched egg-yolk based buttermilk beverage on serum lutein and zeaxanthin concentrations and macular pigment levels. Naturally enriched eggs were made by increasing the levels of the xanthophylls lutein and zeaxanthin in the feed given to laying hens. One hundred healthy volunteers were recruited and randomized into 5 groups for 90 days. Group one added one normal egg to their daily diet and group two received a lutein enriched egg-yolk based beverage. Group three added one lutein enriched egg and group four one zeaxanthin enriched egg to their diet. Group five was the control group and individuals in this group did not modify their daily diet. Serum lutein and zeaxanthin concentrations and macular pigment densities were obtained at baseline, day 45 and day 90. Macular pigment density was measured by heterochromatic flicker photometry. Serum lutein concentration in the lutein enriched egg and egg yolk-based beverage groups increased significantly (p<0.001, 76% and 77%). A strong increase in the serum zeaxanthin concentration was observed in individuals receiving zeaxanthin enriched eggs (P< 0.001, 430%). No changes were observed in macular pigment density in the various groups tested. The results indicate that daily consumption of lutein or zeaxanthin enriched egg yolks as well as an egg yolk-based beverage show increases in serum lutein and zeaxanthin levels that are comparable with a daily use of 5 mg supplements.Trial RegistrationClinicalTrials.gov NCT00527553

Highlights

As the world’s population ages, more and more people are affected by age-related macular degeneration (AMD), leading to an increased awareness and interest in the prevention and treatment of this blinding disease [1,2].The xanthophylls lutein and zeaxanthin are not endogenously synthesized by the human body and tissue levels depend on dietary intake
A similar increase of 77% was observed in the group taking a lutein enriched egg beverage
Our data are in agreement with earlier studies that showed that the daily consumption of eggs results in significantly increased serum xanthophyll levels [18,20,26,27,28].consumption of lutein or zeaxanthin enriched egg yolks led to a higher increase in xanthophylls blood levels compared to studies using ‘‘normal’’ eggs

Summary

Introduction

The xanthophylls lutein and zeaxanthin are not endogenously synthesized by the human body and tissue levels depend on dietary intake. These natural compounds found in the bodies of animals, and in dietary animal products, are derived from plant sources in the diet, mainly from dark green leafy plants. The xanthophylls lutein, zeaxanthin and meso-zeaxanthin are naturally occurring macular pigments, giving the fovea its’ yellowish color [3]. These specific xanthophylls do not function in the mechanism of sight, since they cannot be converted to retinal. Recent evidence suggests that they have anti-inflammatory properties thereby reducing immunemediated damage to the macula [7,8]

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