|Title||Symposium 2 : Nutrient interactions and their role in protection from chronic diseases: β-Carotene in the human body: Metabolic bioactivation pathways - From digestion to tissue distribution and excretion|
|Author(s)||Bohn, Torsten; Desmarchelier, Charles; El, Sedef N.; Keijer, Jaap; Schothorst, Evert Van; Rühl, Ralph; Borel, Patrick|
|Source||Proceedings of the Nutrition Society 78 (2019)1. - ISSN 0029-6651 - p. 68 - 87.|
Human and Animal Physiology
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Absorption - Apo-carotenoids - Micellisation - Nuclear hormone receptor - Retinoic acid - SNPs - Vitamin A|
β-Carotene intake and tissue/blood concentrations have been associated with reduced incidence of several chronic diseases. Further bioactive carotenoid-metabolites can modulate the expression of specific genes mainly via the nuclear hormone receptors: retinoic acid receptor- and retinoid X receptor-mediated signalling. To better understand the metabolic conversion of β-carotene, inter-individual differences regarding β-carotene bioavailability and bioactivity are key steps that determine its further metabolism and bioactivation and mediated signalling. Major carotenoid metabolites, the retinoids, can be stored as esters or further oxidised and excreted via phase 2 metabolism pathways. In this review, we aim to highlight the major critical control points that determine the fate of β-carotene in the human body, with a special emphasis on β-carotene oxygenase 1. The hypothesis that higher dietary β-carotene intake and serum level results in higher β-carotene-mediated signalling is partly questioned. Alternative autoregulatory mechanisms in β-carotene / retinoid-mediated signalling are highlighted to better predict and optimise nutritional strategies involving β-carotene-related health beneficial mediated effects.