Abstract
Purpose: :
To analyze the effect of a 20mg/daily Zx supplement (EyePromise-Ten, ZeaVision) on MPOD in a group of White healthy non-smoking participants of BMI ≤30.
Methods: :
MPOD was measured (participants, n=24; age range: 50-81 yo; M/F=9/15) at 0.5 and 2.0-deg eccentricity by heterochromatic flicker photometry according to published methods (IOVS 2007; 48: 1458-65) at baseline (BL), after 4-mo of 20md/day Zx [Follow-up Visit 4 (FUV4)] and after a 4-mo wash-out (FUV8). Compliance, diet, lifestyle, and BMI changes were ascertained. Averages, correlations, inter-gender comparisons, and percent variations (Δ%) were calculated.
Results: :
Diet and lifestyle were unchanged. Compliance was ≥90% in all cases. MPOD at 0.5-deg increased significantly at both FUV4 and FUV8(BL: 0.40±0.17; FUV4: 0.49±0.19; FUV8: 0.50±0.17, p-value for paired t-test <<0.00001 for both). Significant increases occurred in both genders (Mean Δ% at FUV4: F: +16%, M: +23%), continued further at FUV8 in females (Mean Δ% at FUV8: +20%), but plateaued in males (+21%). MPOD at 2.0-deg showed the same trend (0.16±0.08 at BL; 0.20±0.10 at FUV4, p=0.0001; 0.21±0.09 at FUV8, p=0.00002). Significant increases occurred in both genders (Mean Δ% at FUV4: F: +12%, M: +20%) and continued further at FUV8 only in females (Mean Δ% at FUV8: +27%; M: +11%, p>0.05). Correlations: Increases in MPOD were inversely proportional to BL values, subjects with lower BL MPOD experiencing the largest increases and vice versa (Pearson’s r vs. BL for MPOD 0.5-deg=0.45 at FUV4 and 0.62 at FUV8; 2.0-deg: 0.17 at FUV4 and 0.43 at FUV8). BMI increased slightly during supplementation (BL, mean±1SD: 25.9±2.6; FUV4: 26.3±2.7, Δ% +1.57%; FUV8: 26.0±2.6). There was no significant correlation between Δ% MPOD and Δ% BMI for either 0.5- or 2.0-deg values.
Conclusions: :
Supplementation with 20mg Zx increases significantly MPOD. As noted by van de Kraats et al. in 3 young males (IOVS 2008; 49:5568-73), and unlike what seen by many with lutein, post-Zx MPOD increases are sustained well after wash-out. This effect is strongest in females, who experience even more MPOD increase after wash-out at both 0.5-and 2.0-deg. These delayed and sustained effects seen for Zx, and the observed M/F differences, may be due to distinct interactions with peripheral tissues (e.g., storage in, and release from fat), different abilities to store and/or retain Zx in the retina, both, or other yet unaccounted for factors.
Keywords: macular pigment • clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology