The Effect of Avocado Consumption on Vascular Health

This study has been completed.
Sponsor:
Collaborator:
Hass Avocado Board
Information provided by (Responsible Party):
Janet Novotny, USDA Beltsville Human Nutrition Research Center
ClinicalTrials.gov Identifier:
NCT01595607
First received: February 7, 2012
Last updated: December 10, 2012
Last verified: December 2012
  Purpose

The study will investigate the effect of avocado consumption on markers of vascular health. Sixty participants will be enrolled in the 6-week study. A randomized parallel design will be utilized. Participants will either receive a typical American diet, or a modified typical American diet in which avocado is substituted for foods that contain moderate and high amounts of saturated fat, to allow the isoenergetic inclusion of avocado.


Condition Intervention
Focus: Avocado Consumption & Vascular Health
Other: Diet Treatment

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: The Influence of Daily Consumption of Avocado on Biomarkers of Vascular Health

Further study details as provided by USDA Beltsville Human Nutrition Research Center:

Primary Outcome Measures:
  • Change in Endothelial Function [ Time Frame: 0 hr and 3 hr at baseline and after 6 weeks ] [ Designated as safety issue: No ]
    Noninvasive endothelial function will be assessed, following a 12-hours fast, by measuring endothelium-dependent flow mediated dilation of the peripheral bed. Participants will then consume a test meal and endothelial function will be assessed again 3 hours later.


Secondary Outcome Measures:
  • Change in Blood Pressure [ Time Frame: Baseline and after 6 weeks ] [ Designated as safety issue: No ]
    Blood pressure will be measured using a standardized protocol at the beginning and end of the intervention.

  • Change in Gene Expression [ Time Frame: Baseline and after 6 weeks ] [ Designated as safety issue: No ]
    Blood samples will be used to test how the intervention affects gene expression. The expression of genes related to cardiovascular disease risk will be measured at the beginning and end of the 6-week intervention (fasted and post-prandially).

  • Change in Biomarkers of Cardiovascular Disease Risk [ Time Frame: Baseline and after 6 weeks ] [ Designated as safety issue: No ]
    Blood will be collected at the beginning and end of the dietary intervention, following the endothelial function measurements (fasted and post-prandial collections). Blood will be assessed for biomarkers of cardiovascular disease risk, including electrolytes (sodium, potassium, chloride), markers of inflammation (IL-6, IL-10, IL-1 beta, C-reactive protein, TNF-alpha, fibrinogen, ICAM), markers of vascular function (endothelin-1, factor VII, plasminogen), and blood lipid panel (plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides).


Enrollment: 60
Study Start Date: April 2012
Study Completion Date: July 2012
Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Typical American Diet
Participants will receive a typical American diet for 6 weeks.
Other: Diet Treatment
Participants will consume a controlled diet for 6 weeks where all meals will be provided by the facility. Participants will be instructed to eat all foods and only foods provided to them.
Experimental: Avocado Diet
Participants will receive a modified typical American diet in which avocado is substituted for foods that contain moderate and high amounts of saturated fat to allow the inclusion of avocado.
Other: Diet Treatment
Participants will consume a controlled diet for 6 weeks where all meals will be provided by the facility. Participants will be instructed to eat all foods and only foods provided to them.

  Eligibility

Ages Eligible for Study:   28 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • BMI between 25 and 42 kg/m2
  • Age 28 to 70 years during the intervention
  • Fasting glucose ≤ 126 mg/dl
  • Blood pressure ≤ 160/100 mm Hg

Exclusion Criteria:

  • Presence of kidney disease, liver disease, gout, certain cancers, thyroid disease, gastrointestinal, other metabolic diseases, or malabsorption syndromes
  • Women who have given birth during the previous 12 months
  • Pregnant women or women who plan to become pregnant or become pregnant during the study
  • Lactating women
  • Type 2 diabetes requiring the use of oral antidiabetic agents or insulin
  • History of eating disorders or other dietary patterns which are not consistent with the dietary intervention (e.g., vegetarians, very low fat diets, high protein diets)
  • Volunteers who routinely participate in "heavy" exercise or volunteers who initiate an exercise program during the study.
  • Volunteers who have lost 10% of body weight within the last 12 months
  • Use of prescription or over-the-counter antiobesity medications or supplements (e.g., phenylpropanalamine, ephedrine, caffeine, during and for at least 6 months prior to the start of the study) or history of a surgical intervention for obesity
  • Active cardiovascular disease (such as heart attack or procedure within the past three months or participation in a cardiac rehabilitation program within last three months, stroke or history/treatment for transient ischemic attacks in the past three months, or documented history of pulmonary embolus in past six months)
  • Smokers or other tobacco users (during the 6 months prior to the start of the study)
  • Unable or unwilling to give informed consent or communicate with study staff
  • Self-report of alcohol or substance abuse within the past twelve months and/or current acute treatment or rehabilitation program for these problems (Long-term participation in Alcoholics Anonymous is not an exclusion.)
  • Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol.
  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: NCT01595607

Locations
United States, Maryland
USDA Beltsville Human Nutrition Research Center
Beltsville, Maryland, United States, 20705
Sponsors and Collaborators
USDA Beltsville Human Nutrition Research Center
Hass Avocado Board
  More Information

No publications provided

Responsible Party: Janet Novotny, Research Physiologist, USDA Beltsville Human Nutrition Research Center
ClinicalTrials.gov Identifier: NCT01595607     History of Changes
Other Study ID Numbers: HS39
Study First Received: February 7, 2012
Last Updated: December 10, 2012
Health Authority: United States: Federal Government

ClinicalTrials.gov processed this record on September 18, 2014