PREFERENTIAL INCREASE IN CHYLOMICRON LEVELS OF THE XANTHOPHYLLS LUTEIN AND ZEAXANTHIN COMPARED TO BETA-CAROTENE IN THE HUMAN

The time-course of appearance of five carotenoids in chylomicrons and their distribution pattern were studied following ingestion of a singl e dose of Betatene, a natural carotenoid source composed of 0.5% lutei n, 0.75% zeaxanthin, 3.6% alpha-carotene, 70.3% all-trans beta-caroten e, 22.7% beta-carotene cis isomers, 2.1% unidentified carotenoids and no lycopene. Lutein, zeaxanthin, alpha-carotene and all-trans beta-car otene but not lycopene levels in chylomicrons increased after Betatene ingestion with a maximum at 9 h and a distinct decline from 9 to 12 h . However the carotenoid pattern in the chylomicron fraction did not m atch the pattern in Betatene, with a 14-fold and 4-fold higher level o f lutein and zeaxanthin, respectively, compared to their content in Be tatene. The contribution of alpha-carotene to the carotenoid compositi on in chylomicrons reflected its content in Betatene, whereas the rela tive amount of all-trans beta-carotene was substantially lower than in Betatene. Thus, in the presence of high amounts of beta-carotene, the re is a preferential uptake of the xanthophylls lutein and zeaxanthin as compared to all-trans beta-carotene from the intestinal lumen into chylomicrons.