The Effect of Avocado on Cardiovascular Disease (CVD) Risk Factors

This study has been completed.
Sponsor:
Collaborator:
Hass Avocado Board
Information provided by (Responsible Party):
Penny Kris-Etherton, Penn State University
ClinicalTrials.gov Identifier:
NCT01235832
First received: November 5, 2010
Last updated: September 30, 2013
Last verified: September 2013
  Purpose

The investigators propose to evaluate the effects of avocado consumption (by incorporating 1 unit of fruit per day into a healthy diet) on multiple cardiovascular disease (CVD) risk factors. The investigators will compare chronic consumption of a moderate fat blood cholesterol-lowering diet incorporating one avocado per day versus a blood cholesterol-lowering Lower-Fat diet on established CVD risk factors including lipids and lipoproteins, and blood pressure (BP). The investigators also will evaluate the effects of an avocado diet on several emerging CVD risk factors. To elucidate the specific benefits of avocado and its accompanying bioactives on the aforementioned risk factors, the investigators will compare the avocado diet with a diet that has the same macronutrient profile (but without the avocado).


Condition Intervention
Cardiovascular Disease
Other: Avocado Diet
Other: Lower-Fat Diet
Other: Moderate Fat Diet

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: The Effect of One Avocado Per Day on Established and Emerging Cardiovascular Disease (CVD) Risk Factors

Resource links provided by NLM:


Further study details as provided by Penn State University:

Primary Outcome Measures:
  • Lipids and lipoproteins [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]

    Total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides are measured as part of the lipids and lipoprotein profile.

    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks


  • Lipoprotein particle size [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]

    Advanced lipoprotein testing is used to measure LDL particle size and subclasses of HDL and VLDL.

    Diet period one runs for 5 weeks after a 2-week run-in diet (baseline), then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks



Secondary Outcome Measures:
  • Oxidized-LDL [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]
    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks

  • lipid hydroperoxide [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]
    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks

  • Macrophage Cholesterol efflux [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]
    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks

  • HDL anti-inflammatory function [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]
    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks

  • Serum fatty acid profile [ Time Frame: The end of each diet period ] [ Designated as safety issue: No ]
    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks

  • Inflammatory biomarkers [ Time Frame: The end of diet period ] [ Designated as safety issue: No ]

    CRP and IL-6 are measured as the markers of inflammation.

    Diet period one runs for 5 weeks after a 2-week run-in diet, then there is a 2-3 week compliance break, and then diet period two runs for another 5 weeks; then there is a 2-3 week compliance break, and then diet period three runs for another 5 weeks



Enrollment: 54
Study Start Date: November 2010
Study Completion Date: February 2013
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Lower-Fat Diet
The Lower-Fat diet will provide ~24% of calories from fat and meet the SFA and cholesterol recommendations of a Step-II diet recommended by the National Heart, Lung, and Blood Association's National Cholesterol Education Program. SFA will provide 7% of calories, and cholesterol will be less than 200mg/day. Vegetables and fruits in the Lower-Fat diet will be selected from foods that are low in antioxidants.
Other: Lower-Fat Diet
The Lower-Fat diet will provide ~24% of calories from fat and meet the SFA and cholesterol recommendations of a Step-II diet recommended by the National Heart, Lung, and Blood Association's National Cholesterol Education Program. SFA will provide 7% of calories, and cholesterol will be less than 200mg/day. Vegetables and fruits in the Lower-Fat diet will be selected from foods that are low in antioxidants.
Other Name: lower-fat,low SFA diet
Active Comparator: Moderate Fat Diet
This diet is designed to be the control diet for the avocado diet and will have an identical fatty acid profile. MUFA-enriched food (fats) will be substituted for avocado. The substitution foods will not contain antioxidant or cholesterol-lowering components similar to those in avocado.
Other: Moderate Fat Diet
This diet is designed to be the control diet for the avocado diet and will have an identical fatty acid profile. MUFA-enriched food (fats) will be substituted for avocado. The substitution foods will not contain antioxidant or cholesterol-lowering components similar to those in avocado.
Other Name: moderate fat without avocado
Experimental: Avocado Diet
The avocado diet will be designed to ensure that all subjects incorporate 1 avocado (~136g) per day into a moderate fat diet. Both the Lower-Fat diet and avocado diet will be matched for SFA and dietary cholesterol, but will differ in total fat, primarily MUFA as provided by the avocado. The moderate fat plus avocado diet will provide 34% of calories from total fat, 18% calories from MUFA, and 9% calories from PUFA.
Other: Avocado Diet
The avocado diet will be designed to ensure that all subjects incorporate 1 avocado (~136g) per day into a moderate fat diet. Both the Lower-Fat diet and avocado diet will be matched for SFA and dietary cholesterol, but will differ in total fat, primarily MUFA as provided by the avocado. The moderate fat plus avocado diet will provide 34% of calories from total fat, 18% calories from MUFA, and 9% calories from PUFA.
Other Name: moderate fat plus avocado

Detailed Description:

A randomized, 3-period cross-over, controlled feeding study was designed to compare the effects of a moderate fat blood cholesterol-lowering diet that provides one avocado per day (total fat = 34% total energy, MUFA=18%, SFA <7%) to an Average American diet (AAD), Lower-Fat diet (total fat = 24% total energy, SFA <7%), and Moderate Fat diet (with equivalent fatty acid profile to the avocado diet) without avocado. The study population consists of 40 overweight (BMI25-35 kg/m2) men and women with moderately elevated LDL-C, between the25-90th percentiles from NHANES. The investigators hypothesize that a moderate fat heart-healthy diet, including 1 avocado per day will reduce CVD risk factors including lipids, lipoproteins, apolipoproteins, lipoprotein particle size, markers of oxidative stress and inflammation, blood pressure and reverse cholesterol transport compared to an AAD, Lower-Fat diet, and moderate fat diet without avocado.

  Eligibility

Ages Eligible for Study:   21 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • healthy non-smoking
  • overweight (BMI 25-35 kg/m2) men and women
  • LDL-C between the25-90th percentile from NHANES: 105-194mg/dL for males; 98-190mg/dL for females)

Exclusion Criteria:

  • BP >140/90 mmHg;
  • A history of myocardial infarction, stroke, diabetes mellitus, liver disease, kidney disease, and thyroid disease (unless controlled on medication);
  • Lactation, pregnancy, or desire to become pregnant during the study;
  • Cholesterol-lowering medication use;
  • Intake of putative cholesterol-lowering supplements (psyllium, fish oil capsules, soy lecithin, niacin, fiber, flax, and phytoestrogens, stanol/sterol supplemented foods);
  • Vegetarianism;
  • Nut allergies (Other food allergies were reviewed on a case-by-case basis);
  • Refusal to discontinue nutritional supplements, herbs or vitamins
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01235832

Locations
United States, Pennsylvania
Penn State University
University Park, Pennsylvania, United States, 16802
Sponsors and Collaborators
Penn State University
Hass Avocado Board
Investigators
Principal Investigator: Penny M Kris-Etherton, Dr. Penn State University
Study Director: Li Wang Penn State University
  More Information

No publications provided

Responsible Party: Penny Kris-Etherton, Distinguished Professor, Penn State University
ClinicalTrials.gov Identifier: NCT01235832     History of Changes
Other Study ID Numbers: PKE 106
Study First Received: November 5, 2010
Last Updated: September 30, 2013
Health Authority: United States: Institutional Review Board; plus study-specific authorities

Keywords provided by Penn State University:
cholesterol
triglycerides
low-density lipoprotein
high-density lipoprotein
reverse cholesterol transport

Additional relevant MeSH terms:
Cardiovascular Diseases
Antioxidants
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Protective Agents
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on September 30, 2014