The Effect of Daily Consumption of Eggs on Cognitive Function in the Elderly

August 31, 2017 updated by: Tufts University

The Effect of Consumption of 2 Eggs or 4 oz of Egg Substitute Daily for 6 Months on Cognitive Function in Older Adults.

Cognitive impairment is also a major risk factor for development of dementia later in life. Findings from our studies suggest that the carotenoids, lutein and zeaxanthin may be important in cognitive function in the elderly. The investigators have previously reported eggs to be a highly bioavailable source of lutein and zeaxanthin. Our study evaluates long-term egg intervention as a treatment strategy for age-related cognitive impairment which could possibly prevent the onset of dementia. The investigators have also shown that lutein supplementation significantly improved verbal fluency scores in healthy older women. Our studies have shown that egg interventions can significantly increase serum lutein concentrations in older adults. Based on the sum of our findings, the next logical step will be to investigate the ability of lutein and zeaxanthin contained in eggs to influence cognitive function in older adults. The investigators hypothesize that there will be a significant increase in cognitive function measures in older adults provided with meals containing 2 egg/day at the end of 6 months, while no significant improvements will be observed in older adults given daily meals containing egg substitute.

The proposed study is designed as a randomized, placebo controlled trial that tests the effects of 6 month supplementation with 2 eggs/day on cognitive function in older adults. Secondary analyses will determine whether baseline MP density predicts relative effectiveness of the intervention on cognitive function. Secondary outcomes include plasma biomarkers of oxidative stress and inflammation.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The study is designed as a placebo controlled trial that tests the effects of 6 month supplementation with 2 eggs or 4 ounces of egg substitute a day on cognitive function in older adults. Subjects will be randomly assigned to one of the two groups. Secondary analyses will determine whether baseline macular pigment density (a non invasive measure of lutein and zeaxanthin in neural tissue) or choline status predicts relative effectiveness of the intervention on cognitive function. Secondary outcomes include plasma biomarkers of oxidative stress and inflammation, choline bioavailability, and genetic variants related to endogenous choline production. Participants will be recruited from community-dwelling men and women aged > 50 yr, and potential participants will be screened to meet cognitive and functional criteria. Participants will be pre-screened by telephone; those who appear to meet criteria will undergo further screening. The study will include baseline (0 month), 3 and 6 month visits for study procedures, and monthly telephone calls. Given that there is a visible difference between the two interventions (eggs, egg substitute), a blinded study is not possible.

Study Type

Interventional

Enrollment (Actual)

44

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02111
        • Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • men and women age > 50 years
  • BMI 19-30 kg/m2
  • lutein intake of < 3 mg/d
  • DHA (docosahexaehoic acid) intake < 250 mg/d (including supplements)
  • Mini mental state exam (MMSE) score > 24 (Appendix B)
  • macular pigment density < 0.5 at 0.5 degrees
  • Beck Depression Inventory < 20
  • free of known disease;
  • BMI 19-29 kg/m2
  • must be able to give written informed consent
  • have normal hematologic parameters
  • normal values of plasma albumin
  • normal values for liver and kidney function (Appendix A)
  • no use of carotenoid, n3 fatty acid, multivitamin/mineral, or choline supplements (> 3 months).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: egg white (control)
egg whites, 4 ounces per day for six months
Other: eggs or egg whites
2 eggs/day or 4 oz egg whites/day for 6 months
Experimental: eggs
eggs, 2 large per day for 6 months
Other: eggs or egg whites
2 eggs/day or 4 oz egg whites/day for 6 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
cognition
Time Frame: 6 months
measures of attention, executive function, verbal fluency will be made using a sensitive computerized program
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
inflammation
Time Frame: 6 months
markers of inflammation will be made in plasma
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tufts University

Investigators

  • Principal Investigator: Elizabeth J Johnson, PhD, Tufts University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2012

Primary Completion (Actual)

August 1, 2015

Study Completion (Actual)

August 1, 2015

Study Registration Dates

First Submitted

March 13, 2012

First Submitted That Met QC Criteria

June 15, 2012

First Posted (Estimate)

June 18, 2012

Study Record Updates

Last Update Posted (Actual)

September 1, 2017

Last Update Submitted That Met QC Criteria

August 31, 2017

Last Verified

August 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 001 (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES))

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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