Provitamin A Absorption and Conversion With Avocados
Study Details
Study Description
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 |
|---|---|---|
|
N/A |
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Tomato Meal A tomato meal will be fed with and without avocado. |
Other: Post-prandial Feeding Study
|
| Other: Carrot Meal A carrot meal will be fed with and without avocado. |
Other: Post-prandial Feeding Study
|
Outcome Measures
Primary Outcome Measures
- Post-prandial levels of provitamin A and vitamin A [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
- post-prandial antioxidant status of blood [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.
Eligibility Criteria
Criteria
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
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Tobacco use (cigarettes or chewing tobacco)
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Metabolic disease
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Malabsorption disorders
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History of cancer, esophageal, gastric, or intestinal ulcers
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History of liver or kidney insufficiency or failure
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Allergies to tomatoes or tomato products
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Allergies to carrots
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Allergies to avocados
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Obesity (BMI>30)
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Hypercholesterolemia (total cholesterol> 200mg/dL)
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | The Ohio State University Clinical Research Center | Columbus | Ohio | United States | 43210 |
Sponsors and Collaborators
- Ohio State University
- Hass Avocado Board
Investigators
- Principal Investigator: Steven J Schwartz, Ph.D., Ohio State University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 2011H0159
- 60030575