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Completed

NCT Number: NCT01432210

Provitamin A Absorption and Conversion With Avocados

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.

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Key information

Conditions

Healthy

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The Ohio State University Clinical Research Center

Columbus, Ohio, 43210, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Post-prandial Feeding Study

Other

Primary outcomes

  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 outcomes

  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.

Sponsors and collaborators

Lead sponsor

Ohio State University

Other

Collaborators

  • Hass Avocado Board

Registry information

Official study title

Enhancing Human Intestinal Absorption of Carotenoids and Bioconversion of Carotene to Vitamin A in the Presence of Hass Avocados

Important dates

Study start
2011
Primary completion
2012
Study completion
2012
First posted
Sep 12, 2011
Registry last updated
Sep 30, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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