title: Avocado consumption enhances human postprandial provitamin A absorption and conversion from a novel high-β-carotene tomato sauce and from carrots.
abstract: Dietary lipids have been shown to increase bioavailability of provitamin A carotenoids from a single meal, but the effects of dietary lipids on conversion to vitamin A during absorption are essentially unknown. Based on previous animal studies, we hypothesized that the consumption of provitamin A carotenoids with dietary lipid would enhance conversion to vitamin A during absorption compared with the consumption of provitamin A carotenoids alone. Two separate sets of 12 healthy men and women were recruited for 2 randomized, 2-way crossover studies. One meal was served with fresh avocado (Persea americana Mill), cultivated variety Hass (delivering 23 g of lipid), and a second meal was served without avocado. In study 1, the source of provitamin A carotenoids was a tomato sauce made from a novel, high-β-carotene variety of tomatoes (delivering 33.7 mg of β-carotene). In study 2, the source of provitamin A carotenoids was raw carrots (delivering 27.3 mg of β-carotene and 18.7 mg of α-carotene). Postprandial blood samples were taken over 12 h, and provitamin A carotenoids and vitamin A were quantified in triglyceride-rich lipoprotein fractions to determine baseline-corrected area under the concentration-vs.-time curve. Consumption of lipid-rich avocado enhanced the absorption of β-carotene from study 1 by 2.4-fold (P < 0.0001). In study 2, the absorption of β-carotene and α-carotene increased by 6.6- and 4.8-fold, respectively (P < 0.0001 for both). Most notably, consumption of avocado enhanced the efficiency of conversion to vitamin A (as measured by retinyl esters) by 4.6-fold in study 1 (P < 0.0001) and 12.6-fold in study 2 (P = 0.0013). These observations highlight the importance of provitamin A carotenoid consumption with a lipid-rich food such as avocado for maximum absorption and conversion to vitamin A, especially in populations in which vitamin A deficiency is prevalent. This trial was registered at clinicaltrials.gov as NCT01432210.
authors.affiliation: Departments of Food Science and Technology and Human Nutrition and.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Kopec
authors.affiliation: Departments of Food Science and Technology and.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Cooperstone
authors.affiliation: Departments of Food Science and Technology and Institute of Food Science and Biotechnology, Hohenheim University, Stuttgart, Germany.
authors.forename: Ralf M
authors.initials: RM
authors.lastname: Schweiggert
authors.affiliation: Center for Biostatistics, The Ohio State University, Columbus, OH.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Young
authors.affiliation: Human Nutrition and.
authors.forename: Earl H
authors.initials: EH
authors.lastname: Harrison
authors.affiliation: Department of Horticulture and Crop Science, The Ohio State University, Wooster, OH.
authors.forename: David M
authors.initials: DM
authors.lastname: Francis
authors.affiliation: Department of Oncology and Hematology, The Ohio State University Medical Center, Columbus, OH; and.
authors.forename: Steven K
authors.initials: SK
authors.lastname: Clinton
authors.affiliation: Departments of Food Science and Technology and Human Nutrition and schwartz.177@osu.edu.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D001682:Biological Availability; D002338:Carotenoids / Q000493:pharmacokinetics; D018592:Cross-Over Studies; D018552:Daucus carota / Q000737:chemistry*; D004032:Diet; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008019:Life Style; D008074:Lipoproteins / Q000378:metabolism; D018551:Solanum lycopersicum / Q000737:chemistry*; D008297:Male; D027421:Persea; D019518:Postprandial Period / Q000502:physiology*; D011795:Surveys and Questionnaires; D014280:Triglycerides / Q000378:metabolism; D014801:Vitamin A / Q000493:pharmacokinetics*; D055815:Young Adult; D019207:beta Carotene / Q000493:pharmacokinetics
chemical_list: D008074:Lipoproteins; D014280:Triglycerides; C030087:lipoprotein triglyceride; D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids; C041635:alpha-carotene