Serum response to supplemental macular carotenoids in subjects with and without age-related macular degeneration

Abstract

Macular pigment (MP) is composed of lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ). The present study reports on serum response to three different MP supplements in normal subjects (n 27) and in subjects with age-related macular degeneration (AMD) (n 27). Subjects were randomly assigned to: Group 1 (20 mg L and 2 mg Z), Group 2 (10 mg L, 2 mg Z and 10 mg MZ) or Group 3 (3 mg L, 2 mg Z and 17 mg MZ). Serum carotenoids were quantified at baseline, and at 4 and 8 weeks using HPLC. Response data for normal and AMD subjects were comparable and therefore combined for analysis. We report response as the average of the 4-and 8-week concentrations (saturation plateau). Serum L increased significantly in Group 1 (0·036 mmol/l per mg (269 %); P,0·001) and Group 2 (0·079 mmol/l per mg (340 %); P,0·001), with no significant change in Group 3 (0·006 mmol/l per mg (7 %); P¼0·466). Serum Z increased significantly in Group 1 (0·037 mmol/l per mg (69 %); P¼ 0·001) and Group 2 (0·015 mmol/l per mg (75 %); P,0·001), with no significant change in Group 3 (20·0002 mmol/l per mg (26 %); P¼0·384). Serum MZ increased significantly in Group 1 (0·0094 mmol/l (absolute value); P¼ 0·015), Group 2 (0·005 mmol/l per mg; P,0·001) and Group 3 (0·004 mmol/l per mg; P,0·001). The formulation containing all three macular carotenoids (Group 2 supplement) was the most efficacious in terms of achieving the highest combined concentration of the three MP constituent carotenoids in serum, thereby potentially optimising the bioavailability of these compounds for capture by the target tissue (retina).

Central Retinal Enrichment Supplementation Trials (CREST): Design and Methodology of the CREST Randomized Controlled Trials

“…Recent data from our laboratory show that optimal enrichment of MP is dependent upon inclusion of MZ (along with L and Z) in the supplement formulation 79 , 10 MZ is believed to be particularly important for the following reasons. First, MZ is the dominant macular carotenoid at the foveal epicenter,8 and is therefore ideally located to exert optimal antioxidant activity and short-wavelength light filtration at the central macula, the specialized part of the retina responsible for color vision and high spatial resolution 11.…”

Meso-Zeaxanthin (MZ): Current Perspectives and New Insights

“…Table 2 provides a summary of MZ supplementation studies in combination with L/RZ. Human clinical studies demonstrate MZ's protective role for eye health and defense against AMD [26][27][28][29][30][31]. Overall, in these studies, MZ was observed in blood after supplementation.…”

What is meso-zeaxanthin, and where does it come from?

“…Importantly, for this experiment we purified our L standard via HPLC, as previous work by our laboratory indicated the presence of all Z isomers (including MZ) in DSMprovided L standards. 38 Of note, it has also been suggested that MZ may be generated from L as a result of an enzymatic process at the macula, but such a hypothesis has yet to be investigated. 28 Also, and of interest, a recent investigation of serum carotenoid response following supplementation with different macular carotenoid formulations identified an unexpected peak with the spectrophotometric characteristics of MZ in the serum of subjects supplemented with 20 mg of L and 2 mg of Z (Ultra Lutein from Natural Organics Inc., Melville, NY, USA: L provided by FloraGLO, which is a registered trademark of Kemin Health, L.C., Kemin Industries, Inc. Des Moines, IA, USA).…”

“…Given that this was an unexpected finding, we reanalysed random serum samples from these subjects in order to confirm or refute our observation, and confirmed that MZ was, indeed, present. 38 We then tested the intervention formulation, and determined that it did, in fact, contain MZ (0.3 mg/capsule) (Figure 2), although MZ was not claimed on the product label.…”