Independent Effects of High-cholesterol (High-egg) and High-saturated Fat Diets on LDL-cholesterol
Condition: Hypercholesterolemia; Hyperlipidemias; Physical Inactivity; Diet, Healthy
MeSH terms: Hypercholesterolemia; Hyperlipidemias
Study type: Interventional

Summary: 
      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).
    

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).
    

Intervention name(s): Egg diet; Egg-free Diet; Control Diet
Intervention type(s): Other; Other; Other
Intervention description(s): 30% fat [6% saturated fat], 20% protein, 40% carbohydrate, 600 mg cholesterol; 30% fat [12% saturated fat], 25% protein, 40% carbohydrate, 300 mg cholesterol; 30% fat [12% saturated fat], 25% protein, 40% carbohydrate, 600 mg cholesterol
Other intervention name(s): High cholesterol + low saturated fat diet; Low cholesterol + high saturated fat diet; Average Australian Diet
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Counter-balanced, cross-over trial with randomization to the starting diet will be via minimization, based on the LDL-C concentration at screening and sex. Minimization will ensure balanced LDL-C and sex between the treatment groups at commencement of each of the three diets.
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Cholesterol; Eggs; Saturated Fat; Low density lipoprotein cholesterol; lutein; physical activity