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Provitamin A Absorption and Conversion With Avocados

Not Applicable
Completed
Conditions
Healthy
Interventions
Other: Post-prandial Feeding Study
Registration Number
NCT01432210
Lead Sponsor
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.

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
24
Inclusion Criteria
  • Total cholesterol (140 to 200 mg/dL)
  • BMI 17 to 30
  • Age 18-70 years
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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)
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Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Tomato MealPost-prandial Feeding StudyA tomato meal will be fed with and without avocado.
Carrot MealPost-prandial Feeding StudyA carrot meal will be fed with and without avocado.
Primary Outcome Measures
NameTimeMethod
Post-prandial levels of provitamin A and vitamin ANine 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
NameTimeMethod
post-prandial antioxidant status of bloodcomparing 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.

Trial Locations

Locations (1)

The Ohio State University Clinical Research Center

🇺🇸

Columbus, Ohio, United States

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