Clinical trial NCT01432210: Provitamin A Absorption and Conversion With Avocados
Official title: Enhancing Human Intestinal Absorption of Carotenoids and Bioconversion of Carotene to Vitamin A in the Presence of Hass Avocados
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Keywords: post-prandial absorption
provitamin A carotenoids
vitamin A
avocado
tomato
carrot
Lead sponsor: Ohio State University
Sponsor class: OTHER
Collaborators: name: Hass Avocado Board
First posted: 2011-09-12
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.

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)

Primary outcomes:
measure: Post-prandial levels of provitamin A and vitamin A
timeFrame: Nine post-prandial blood samples will be taken over twelve hours
Secondary outcomes:
measure: post-prandial antioxidant status of blood
timeFrame: comparing baseline vs. 5 hour status
Other outcomes:
Locations:
city: Columbus
country: United States
facility: The Ohio State University Clinical Research Center
state: Ohio
Study officials:
affiliation: Ohio State University
name: Steven J Schwartz, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Cooperstone JL, Goetz HJ, Riedl KM, Harrison EH, Schwartz SJ, Kopec RE. Relative contribution of alpha-carotene to postprandial vitamin A concentrations in healthy humans after carrot consumption. Am J Clin Nutr. 2017 Jul;106(1):59-66. doi: 10.3945/ajcn.116.150821. Epub 2017 May 17.
citation: Kopec RE, Cooperstone JL, Schweiggert RM, Young GS, Harrison EH, Francis DM, Clinton SK, Schwartz SJ. Avocado consumption enhances human postprandial provitamin A absorption and conversion from a novel high-beta-carotene tomato sauce and from carrots. J Nutr. 2014 Aug;144(8):1158-66. doi: 10.3945/jn.113.187674. Epub 2014 Jun 4.