A supplementation study in human subjects with a combination of meso-zeaxanthin, (3R,3′R)-zeaxanthin and (3R,3′R,6′R)-lutein

Abstract

We measured the blood uptake of meso-zeaxanthin (MZ) from a mixture of macular pigments since its bioavailability in man has not been studied. Volunteers (ten men and nine women) were recruited and received one capsule of Lutein Plus®/d. Blood was taken at baseline, day 10 and day 22. One capsule contained 10.8 mg lutein, 1.2 mg (3R,3′R)-zeaxanthin and 8.0 mg MZ. Plasma lutein and total zeaxanthin concentrations were quantified using isocratic liquid chromatography and the eluting xanthophyll fractions were collected and re-chromatographed on a chiral column to assess the proportion of MZ. Plasma concentrations per mg dose at day 22 suggested that (3R,3′R)-zeaxanthin (0.088 μmol/l per mg) was about 50% more actively retained by the body than lutein (0.056 μmol/l per mg) (although the difference was not significant in women) and 2.5-3.0 times more than MZ (0.026 μmol/l per mg). Concentrations of MZ at day 22 were 2.5 times higher in women than men. The plasma responses from lutein and (3R,3′R)-zeaxanthin in the Lutein Plus® were lower than literature values for the pure substances. That is, their uptake into plasma appeared to be slightly depressed by the presence of MZ. Plasma concentrations of β-carotene were depressed by about 50% at day 10 and about 35% at day 22. In conclusion, the lower plasma response to MZ compared with (3R,3′R)-zeaxanthin probably indicates that MZ is less well absorbed than (3R,3′R)-zeaxanthin but work with pure MZ will be needed to confirm that the lower plasma response was not due to the large amount of lutein in the Lutein Plus®. © The Authors 2008.