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

• ClinicalTrials.gov Identifier: NCT01235832
• Recruitment Status: Completed
• First Posted: November 8, 2010
• Last Update Posted: April 28, 2015
• Sponsor: Penn State University
• Collaborator: Hass Avocado Board
• Information provided by (Responsible Party): Penny Kris-Etherton, Penn State University

Study Description

Brief Summary:

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 or disease	Intervention/treatment	Phase
Cardiovascular Disease; Hyperlipidemia	Other: Avocado Diet; Other: Lower-Fat Diet; Other: Moderate Fat Diet	Not Applicable

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.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 54 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: None (Open Label)
• Primary Purpose: Prevention
• Official Title: The Effect of One Avocado Per Day on Established and Emerging Cardiovascular Disease (CVD) Risk Factors
• Study Start Date: November 2010
• Actual Primary Completion Date: December 2012
• Actual Study Completion Date: February 2013

Arms and Interventions

Arm	Intervention/treatment
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

Outcome Measures

Primary Outcome Measures :

1. Lipids and lipoproteins [ Time Frame: The end of each diet period ]

   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

2. Lipoprotein particle size [ Time Frame: The end of each diet period ]

   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 :

1. Oxidized-LDL [ Time Frame: The end of each diet period ]
   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
2. lipid hydroperoxide [ Time Frame: The end of each diet period ]
   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
3. Macrophage Cholesterol efflux [ Time Frame: The end of each diet period ]
   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
4. HDL anti-inflammatory function [ Time Frame: The end of each diet period ]
   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
5. Serum fatty acid profile [ Time Frame: The end of each diet period ]
   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
6. Inflammatory biomarkers [ Time Frame: The end of diet period ]

   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

Eligibility Criteria

• Ages Eligible for Study: 21 Years to 70 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• 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

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

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Tindall AM, Kris-Etherton PM, Petersen KS. Replacing Saturated Fats with Unsaturated Fats from Walnuts or Vegetable Oils Lowers Atherogenic Lipoprotein Classes Without Increasing Lipoprotein(a). J Nutr. 2020 Apr 1;150(4):818-825. doi: 10.1093/jn/nxz313.

Wang L, Tao L, Hao L, Stanley TH, Huang KH, Lambert JD, Kris-Etherton PM. A Moderate-Fat Diet with One Avocado per Day Increases Plasma Antioxidants and Decreases the Oxidation of Small, Dense LDL in Adults with Overweight and Obesity: A Randomized Controlled Trial. J Nutr. 2020 Feb 1;150(2):276-284. doi: 10.1093/jn/nxz231.

Wang L, Bordi PL, Fleming JA, Hill AM, Kris-Etherton PM. Effect of a moderate fat diet with and without avocados on lipoprotein particle number, size and subclasses in overweight and obese adults: a randomized, controlled trial. J Am Heart Assoc. 2015 Jan 7;4(1):e001355. doi: 10.1161/JAHA.114.001355.

• Responsible Party: Penny Kris-Etherton, Distinguished Professor, Penn State University
• ClinicalTrials.gov Identifier: NCT01235832
• Other Study ID Numbers: PKE 106
• First Posted: November 8, 2010
• Last Update Posted: April 28, 2015
• Last Verified: April 2015

Keywords provided by Penny Kris-Etherton, Penn State University:

cholesterol; triglycerides; low-density lipoprotein; high-density lipoprotein; reverse cholesterol transport

Additional relevant MeSH terms:

Cardiovascular Diseases; Hyperlipidemias; Dyslipidemias; Lipid Metabolism Disorders; Metabolic Diseases