The Effect of Eggs and Egg Products on Macular Pigment

Overview

Age-related macula degeneration (AMD, encompassing both dry and wet form), the late stage of Age-related maculopathy (ARM), is the leading cause of blindness in many developed countries in older persons (usually over 60 years of age). Visual compromise rises exponentially after the age of 70 with a 5-year incidence of around 1%. Studies have shown a possible protective effect of lutein on progression of AMD, where visual acuity improves after increased lutein intake. The incidence of bilateral AMD in persons with unilateral late ARM observed over a period of 10 years is over 50% with a 2.1-2.8% overall incidence in the study population.

Blue light hazard (excitation peak 440 nm) was shown to have a major impact on photoreceptor and RPE function inducing photochemical damage and cellular apoptosis, leading to retinal degeneration in an animal study. The current belief is that lutein accumulated in the macular region helps in the prevention of blindness by absorbing blue light and protecting the retina from oxidative stress. With the lipid matrix of the egg yolk being a proven vehicle for the efficient absorption of dietary lutein, it might be possible to increase plasma levels of lutein to therapeutic levels and control or prevent AMD. This, the investigators hope, will be accomplished by means of filtering out harmful blue light and the scavenging of free radicals by lutein and zeaxanthin.

Full Title of Study: “The Effect of Modified Eggs and Egg Products on the Measurable Macular Pigment in Healthy Subjects”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Prevention
    • Masking: Single (Investigator)
  • Study Primary Completion Date: February 2008

Detailed Description

This will be a randomized placebo-controlled trial. The total study time will be two years of which 3 months are actual trial and follow-up time. Every individual will have 3 measuring points at set intervals. At every measuring point (days 1, 45 and 90), these subjects will undergo 6 different non-invasive measuring techniques. These are the mean visual acuity test using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, contrast sensitivity using the Pelli-Robson chart, Scanning Laser Ophthalmoscope (SLO), Optical Coherence Tomography (OCT) and Heterochromatic Flicker Photometry (HFP) and the Reflectometer. A questionnaire will be taken at the beginning of the trail. The invasive part of the study involves blood sampling at all three times, measuring the serum concentration of lutein, zeaxanthin, omega-3 and lipoprotein using the HPLC analysis.

Interventions

  • Dietary Supplement: not enriched egg
    • daily consumption of a regular egg, not enriched with either lutien nor zeaxanthin
  • Dietary Supplement: lutein
    • daily lutein enriched egg
  • Dietary Supplement: zeaxanthin
    • daily zeaxanthin enriched egg
  • Dietary Supplement: egg product from enriched eggs
    • daily egg product from lutein enriched eggs

Arms, Groups and Cohorts

  • Experimental: A
    • daily consumption of a regular egg
  • Experimental: B
    • daily consumption of a lutein-enriched egg, eggs laid by chickens on a lutein-enriched feed.
  • Experimental: C
    • daily consumtion of a zeaxanthin-enriched egg, eggs laid by chickens on a zeaxantin-enriched feed.
  • Experimental: D
    • daily egg product from enriched eggs
  • No Intervention: E
    • control subjects were not blinded as they did not receive any aditional supplementation. Only markers measured during the trial period as a control.

Clinical Trial Outcome Measures

Primary Measures

  • Measurable macular pigment
    • Time Frame: 3 months

Secondary Measures

  • Plasma Lutein and zeaxanthin concentrations, lipid profile
    • Time Frame: 3 months

Participating in This Clinical Trial

Inclusion Criteria

  • No history of ARM or AMD
  • 18 years and older
  • Non-smoker
  • No ocular media opacity
  • Uses no nutritional supplements containing Lutein, Zeaxanthin or Omega-3
  • BMI < 30
  • No known cardiovascular disease

Exclusion Criteria

  • Diabetes
  • Other known eye disease
  • Known lipid metabolism disease
  • Blood lipid level modifiers (e.g., Statin)
  • Known allergy to eggs or egg products

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 80 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Maastricht University Medical Center
  • Collaborator
    • SenterNovem
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • T. T.J. Berendschot, Dr., Principal Investigator, Maastricht University Medical Center

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