Avocado Consumption Enhances Human Postprandial Provitamin A Absorption and Conversion From a Novel high-β-carotene Tomato Sauce and From Carrots

J Nutr. 2014 Aug;144(8):1158-66. doi: 10.3945/jn.113.187674. Epub 2014 Jun 4.

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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Biological Availability
  • Carotenoids / pharmacokinetics
  • Cross-Over Studies
  • Daucus carota / chemistry*
  • Diet
  • Female
  • Healthy Volunteers
  • Humans
  • Life Style
  • Lipoproteins / metabolism
  • Lycopersicon esculentum / chemistry*
  • Male
  • Persea*
  • Postprandial Period / physiology*
  • Surveys and Questionnaires
  • Triglycerides / metabolism
  • Vitamin A / pharmacokinetics*
  • Young Adult
  • beta Carotene / pharmacokinetics

Substances

  • Lipoproteins
  • Triglycerides
  • lipoprotein triglyceride
  • beta Carotene
  • Vitamin A
  • Carotenoids
  • alpha-carotene

Associated data

  • ClinicalTrials.gov/NCT01432210