Provitamin A Absorption and Conversion With Avocados

Study Overview
=================
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.

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

Conditions
-----------------
Healthy

Intervention / Treatment
-----------------
* Other: Post-prandial Feeding Study


Participation Criteria
=================
Eligibility 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 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)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Tomato Meal<br>A tomato meal will be fed with and without avocado. | Other: Post-prandial Feeding Study<br> <br> |
| Other: Carrot Meal<br>A carrot meal will be fed with and without avocado. | Other: Post-prandial Feeding Study<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-prandial levels of provitamin A and vitamin A | 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. | Nine post-prandial blood samples will be taken over twelve hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| post-prandial antioxidant status of blood | 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. | comparing baseline vs. 5 hour status | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
post-prandial absorption, provitamin A carotenoids, vitamin A, avocado, tomato, carrot