Independent Effects of High-cholesterol (High-egg) and High-saturated Fat Diets on LDL-cholesterol

This study will comprise a randomized controlled, counter-balanced, cross-over trial to evaluate the independent effects of a high cholesterol (high egg), low saturated fat diet and a high saturated fat, low cholesterol diet on blood lipids. Evaluations also include analysis of physical activity as there is emerging evidence that the lutein and zeaxanthin in egg yolk may increase physical activity levels by crossing the blood-brain barrier and altering neuronal function. The study will also investigate effects on a number of novel lipoprotein parameters (particle size and particle concentrations).

Study Overview

• Status: Completed
• Conditions: Hypercholesterolemia; Hyperlipidemias; Diet, Healthy; Physical Inactivity
• Intervention / Treatment: Other: Egg diet; Other: Egg-free Diet; Other: Control Diet

Detailed Description

Eggs are high in cholesterol but low in saturated fat. Data from cross-sectional, prospective, and randomized controlled trials (RCTs), suggest that egg intake does not adversely affect blood lipids or increase cardiovascular disease (CVD) risk. In fact, there is some evidence that egg consumption may reduce CVD risk. However, to date there has been no direct comparison of the effects of a high cholesterol (high egg), low saturated fat diet and a low cholesterol, high-saturated fat diet on blood lipids, and no studies have accounted for potential effects of differences in physical activity, which can also influence the blood lipid profile. Evaluations of the effect of egg consumption on blood lipids should include analysis of physical activity as there is emerging evidence that the lutein and zeaxanthin in egg yolk may increase physical activity levels by crossing the blood-brain barrier and altering neuronal function. We will directly compare the effects of a high cholesterol, low saturated fat diet and a low cholesterol, high saturated fat diet on blood lipids, using egg consumption to manipulate dietary cholesterol intake, while also accounting for physical activity levels. The study will investigate effects on a number of novel lipoprotein parameters (particle size and particle concentrations).

• Study Type: Interventional
• Enrollment (Actual): 77
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Australia
  • South Australia
    • Adelaide, South Australia, Australia, 5000
      • University of South Australia Clinical Trial Facility

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male or female, aged 18 - 60 years
• Blood LDL-C <3.5 mmol/L (measured at screening using an automated analyser (Cholestech LDX System).
• Non-smoker (or other nicotine products) (minimum 6 months).

Exclusion Criteria:

• Have diagnosed cardiovascular disease (including uncontrolled high blood pressure) or a chronic disease, including Type-1 or -2 diabetes, kidney or liver disease, gastrointestinal disorders requiring medical nutrition therapy (e.g., Crohn's disease, irritable bowel, coeliac disease) or any other condition that may have an impact on study outcomes.
• Have allergies or strong aversion to eggs or other components of the test foods (diets are not suitable for vegetarians).
• Consume more than 5 eggs per week in the month prior to beginning the trial.
• Participant has a recent history (within 12 months) or strong potential for alcohol abuse. Defined as >14 standard drinks per week.
• Have changed medication or supplementation that might affect study outcomes in the last 3 months.
• Take vitamin, mineral, herbal supplementation, or medications that may have an impact on study outcomes.
• Are already involved in another research project within 30 days of commencement of the present study that in the opinion of the investigators will be unsuitable for this study.
• Are pregnant or breastfeeding.
• Show unwillingness to be randomized to either experimental group.
• Failure to satisfy the investigator regarding suitability to participate for any other reason.
• Are unwilling or unable to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Egg Diet; Egg diet, contains 2 eggs per day and limits saturated fat to 6% of energy intake. Cholesterol intake is 600mg/day. Protein and carbohydrate levels will be maintained at 20% and 40% of energy intake, respectively. This diet will be followed for 5 weeks.	Other: Egg diet; 30% fat [6% saturated fat], 20% protein, 40% carbohydrate, 600 mg cholesterol; Other Names: High cholesterol + low saturated fat diet
Active Comparator: Egg-free Diet; Egg-free diet, limits cholesterol to 300 mg/day (no eggs) with saturated fat intake at 12% of energy intake. Protein and carbohydrate levels will be maintained at 25% and 40% of energy intake, respectively. This diet will be followed for 5 weeks.	Other: Egg-free Diet; 30% fat [12% saturated fat], 25% protein, 40% carbohydrate, 300 mg cholesterol; Other Names: Low cholesterol + high saturated fat diet
Active Comparator: Control Diet; Comparator diet based on the average Australian diet, limited to 1 egg per week, with saturated fat intake at 12% of energy intake. Cholesterol intake is 600 mg/day. Protein and carbohydrate levels will be maintained at 25% and 40% of energy intake, respectively. This diet will be followed for 5 weeks.	Other: Control Diet; 30% fat [12% saturated fat], 25% protein, 40% carbohydrate, 600 mg cholesterol; Other Names: Average Australian Diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Low-density lipoprotein cholesterol (LDL-C)	Plasma LDL-C levels (mmol/L)	Baseline
Low-density lipoprotein cholesterol (LDL-C)	Plasma LDL-C levels (mmol/L)	5 weeks
Low-density lipoprotein cholesterol (LDL-C)	Plasma LDL-C levels (mmol/L)	10 weeks
Low-density lipoprotein cholesterol (LDL-C)	Plasma LDL-C levels (mmol/L)	15 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood lipid profiling	Plasma lipid, lipoprotein subclasses, cholesterol, and apolipoproteins	Baseline
Blood lipid profiling	Plasma lipid, lipoprotein subclasses, cholesterol, and apolipoproteins	5 weeks
Blood lipid profiling	Plasma lipid, lipoprotein subclasses, cholesterol, and apolipoproteins	10 weeks
Blood lipid profiling	Plasma lipid, lipoprotein subclasses, cholesterol, and apolipoproteins	15 weeks
Fasting glucose	Plasma glucose levels (mmol/L)	Baseline
Fasting glucose	Plasma glucose levels (mmol/L)	5 weeks
Fasting glucose	Plasma glucose levels (mmol/L)	10 weeks
Fasting glucose	Plasma glucose levels (mmol/L)	15 weeks
Physical activity levels	Amount of time (min) spent sedentary and engaged in light or moderate-vigorous physical activity	Baseline
Physical activity levels	Amount of time (min) spent sedentary and engaged in light or moderate-vigorous physical activity	5 weeks
Physical activity levels	Amount of time (min) spent sedentary and engaged in light or moderate-vigorous physical activity	10 weeks
Physical activity levels	Amount of time (min) spent sedentary and engaged in light or moderate-vigorous physical activity	15 weeks
Waist circumference	Waist circumference (cm) measured at the midpoint between the lower costal (10th rib) border and the iliac crest.	Baseline
Waist circumference	Waist circumference (cm) measured at the midpoint between the lower costal (10th rib) border and the iliac crest.	5 weeks
Waist circumference	Waist circumference (cm) measured at the midpoint between the lower costal (10th rib) border and the iliac crest.	10 weeks
Waist circumference	Waist circumference (cm) measured at the midpoint between the lower costal (10th rib) border and the iliac crest.	15 weeks
Blood Pressure	Seated blood pressure (mmHg)	Baseline
Blood Pressure	Seated blood pressure (mmHg)	5 weeks
Blood Pressure	Seated blood pressure (mmHg)	10 weeks
Blood Pressure	Seated blood pressure (mmHg)	15 weeks
Dietary saturated fat intake	Analysis of dietary intake based on 5-day food diaries	Baseline
Dietary saturated fat intake	Analysis of dietary intake based on 5-day food diaries	5 weeks
Dietary saturated fat intake	Analysis of dietary intake based on 5-day food diaries	10 weeks
Dietary saturated fat intake	Analysis of dietary intake based on 5-day food diaries	15 weeks
Dietary cholesterol intake	Analysis of dietary intake based on 5-day food diaries	Baseline
Dietary cholesterol intake	Analysis of dietary intake based on 5-day food diaries	5 weeks
Dietary cholesterol intake	Analysis of dietary intake based on 5-day food diaries	10 weeks
Dietary cholesterol intake	Analysis of dietary intake based on 5-day food diaries	15 weeks
Dietary Energy intake	Analysis of dietary intake based on 5-day food diaries	Baseline
Dietary Energy intake	Analysis of dietary intake based on 5-day food diaries	5 weeks
Dietary Energy intake	Analysis of dietary intake based on 5-day food diaries	10 weeks
Dietary Energy intake	Analysis of dietary intake based on 5-day food diaries	15 weeks
Dietary Macronutrients	Analysis of dietary intake based on food diaries	Baseline
Dietary Macronutrients	Analysis of dietary intake based on food diaries	5 weeks
Dietary Macronutrients	Analysis of dietary intake based on food diaries	10 weeks
Dietary Macronutrients	Analysis of dietary intake based on food diaries	15 weeks
Dietary Lutein+Zeaxanthin	Analysis of dietary intake based on food diaries	Baseline
Dietary Lutein+Zeaxanthin	Analysis of dietary intake based on food diaries	5 weeks
Dietary Lutein+Zeaxanthin	Analysis of dietary intake based on food diaries	10 weeks
Dietary Lutein+Zeaxanthin	Analysis of dietary intake based on food diaries	15 weeks
Sleep	Sleep patterns assessed using accelerometers	Baseline
Sleep	Sleep patterns assessed using accelerometers	5 weeks
Sleep	Sleep patterns assessed using accelerometers	10 weeks
Sleep	Sleep patterns assessed using accelerometers	15 weeks

Collaborators and Investigators

• Sponsor: University of South Australia
• Collaborators: American Egg Board
• Investigators: Principal Investigator: Jonathan D Buckley, PhD, University of South Australia

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2022
• Primary Completion (Actual): August 10, 2023
• Study Completion (Actual): August 31, 2023

Study Registration Dates

• First Submitted: February 2, 2022
• First Submitted That Met QC Criteria: March 1, 2022
• First Posted (Actual): March 4, 2022

Study Record Updates

• Last Update Posted (Estimated): December 13, 2023
• Last Update Submitted That Met QC Criteria: December 11, 2023
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: physical activity; Cholesterol; lutein; Eggs; Saturated Fat; Low density lipoprotein cholesterol
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Dyslipidemias; Hypercholesterolemia; Hyperlipidemias
• Other Study ID Numbers: 204327

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No