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Provitamin A Absorption and Conversion With Avocados

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01432210
Recruitment Status : Completed
First Posted : September 12, 2011
Last Update Posted : September 30, 2016
Hass Avocado Board
Information provided by (Responsible Party):
Jessica Cooperstone, Ohio State University

Brief Summary:
Vitamin A is necessary in the human diet. The form of vitamin A found in fruits and vegetables is not "active" and must be converted to the active form in the human body. However, information on the ability of humans to absorb and convert vitamin A to the active form is still lacking. In this study, the investigators will observe the absorption and conversion of vitamin A from orange tomato sauce and/or carrots after a meal with fat (from avocado fruit) and a meal without fat. The investigators will also test whether eating these foods might protect the blood against damage that could lead to heart disease.

Condition or disease Intervention/treatment Phase
Healthy Other: Post-prandial Feeding Study Not Applicable

Detailed Description:

The primary objective of this study will be to demonstrate that adding avocados to a carotene rich meal will promote the absorption of provitamin A carotenoids and enhance the delivery of greater quantities of vitamin A. This objective will be accomplished by quantitation of the immediate post-prandial plasma concentrations of parent carotenoids and vitamin A metabolites after subjects consume a meal with or without avocado in combination with a serving of tomato sauce (containing nutritionally relevant amounts of beta-carotene) or carrots.

The secondary objective of this study will be to determine if higher levels of carotenoids and other antioxidants transported in the bloodstream will have a protective role in promoting cardiovascular health. This objective will be accomplished by testing the oxidation capacity of lipoprotein fractions before and after meal supplementation.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Enhancing Human Intestinal Absorption of Carotenoids and Bioconversion of Carotene to Vitamin A in the Presence of Hass Avocados
Study Start Date : September 2011
Actual Primary Completion Date : January 2012
Actual Study Completion Date : March 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin A

Arm Intervention/treatment
Tomato Meal
A tomato meal will be fed with and without avocado.
Other: Post-prandial Feeding Study
Carrot Meal
A carrot meal will be fed with and without avocado.
Other: Post-prandial Feeding Study

Primary Outcome Measures :
  1. Post-prandial levels of provitamin A and vitamin A [ Time Frame: Nine post-prandial blood samples will be taken over twelve hours ]
    The absorption of and conversion of provitamin A carotenoids into vitamin A will be measured after the consumption of a carotenoid-rich meal. The meal will be served both with and without avocado as a source of lipid.

Secondary Outcome Measures :
  1. post-prandial antioxidant status of blood [ Time Frame: comparing baseline vs. 5 hour status ]
    The ability of a carotenoid-rich meal to reduce the susceptibility of blood lipoproteins to oxidative stress will be tested. A modified trolox equivalent antioxidant capacity (TEAC) assay will be used.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Total cholesterol (140 to 200 mg/dL)
  • BMI 17 to 30
  • Age 18-70 years

Exclusion Criteria:

  • Lactating, pregnant, or plan to be pregnant during study
  • Tobacco use (cigarettes or chewing tobacco)
  • Metabolic disease
  • Malabsorption disorders
  • History of cancer, esophageal, gastric, or intestinal ulcers
  • History of liver or kidney insufficiency or failure
  • Allergies to tomatoes or tomato products
  • Allergies to carrots
  • Allergies to avocados
  • Obesity (BMI>30)
  • Hypercholesterolemia (total cholesterol> 200mg/dL)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01432210

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United States, Ohio
The Ohio State University Clinical Research Center
Columbus, Ohio, United States, 43210
Sponsors and Collaborators
Ohio State University
Hass Avocado Board
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Principal Investigator: Steven J Schwartz, Ph.D. Ohio State University
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Jessica Cooperstone, Research Scientist, Ohio State University Identifier: NCT01432210    
Other Study ID Numbers: 2011H0159
60030575 ( Other Identifier: OSURF )
First Posted: September 12, 2011    Key Record Dates
Last Update Posted: September 30, 2016
Last Verified: September 2016
Keywords provided by Jessica Cooperstone, Ohio State University:
post-prandial absorption
provitamin A carotenoids
vitamin A