Clinical Effects of Dietary Supplementation of Lutein with High Bio-Accessibility on Macular Pigment Optical Density and Contrast Sensitivity: A Randomized Double-Blind Placebo-Controlled Parallel-Group Comparison Trial

Abstract

Improvements in macular pigment optical density (MPOD) and contrast sensitivity after administration of 12 mg lutein alone and the timing at which efficacy is observed remain unknown. Therefore, lutein (12 mg), a crystalline formulation, was used in this study, considering its bioaccessibility. This study aimed to determine the effects of lutein administration for 16 weeks on MPOD, contrast sensitivity, and glare sensitivity, and changes in serum lutein levels were determined. The study subjects comprised 59 healthy male and female adults aged 20–69 years. The study diet included a placebo (placebo group) or a diet supplemented with 12 mg of lutein (lutein group). Each study diet was continuously administered for 16 weeks. At weeks 8 and 16, MPOD, contrast sensitivity, glare sensitivity, and serum lutein levels were evaluated. Compared with the placebo group, the lutein group showed significantly improved MPOD, contrast sensitivity, and glare sensitivity at week 16 and significantly increased serum lutein levels at weeks 8 and 16. Continuous administration of lutein for 16 weeks, considering its bioaccessibility, increased MPOD; it made the outlines of visible objects clearer and was effective in inhibiting decreases in visual function caused by glare from light.

Beyond Nutrient Deficiency—Opportunities to Improve Nutritional Status and Promote Health Modernizing DRIs and Supplementation Recommendations

“…Lutein from foods or supplem creases blood levels and macular pigment optical density (MPOD) in the retina i dependent manner (Figure 3) [81][82][83]. MPOD is related to static indicators of visual performance, such as glare and sensitivity, and dynamic measures of visual performance such as the critical flick threshold [84][85][86]. MPOD is also related to measures of cognitive function such fluency, memory, processing speed and accuracy [76].…”

“…The omega-3 (n-3) long-chain polyunsaturated fatty acids EPA (C20:5n-3) a MPOD is related to static indicators of visual performance, such as glare and contrast sensitivity, and dynamic measures of visual performance such as the critical flicker fusion threshold [84][85][86]. MPOD is also related to measures of cognitive function such as verbal fluency, memory, processing speed and accuracy [76].…”

Polyunsaturated Lipids in the Light-Exposed and Prooxidant Retinal Environment

“…Both lutein and zeaxanthin absorb blue light with a peak close to 450 when incorporated in liposomes [ 175 ]. A randomized, double-blind, placebo-controlled clinical trial in 59 male and female subjects aged 20–69 years found evidence that 16 weeks of diet supplemented with 12 mg/d lutein improved macular pigment density and prevented the loss of resolution due to optical glare [ 176 ], an effect related to blue light absorption by xanthophylls rather than by their antioxidant properties. Recently, xanthophylls have been proposed to operate as light-modulated sunscreen with light absorption, causing trans - cis photoisomerization, promoting their reorientation in the membrane plane and increasing their ability to absorb incident blue light in model membranes as well as in the human retina [ 177 ].…”

Lutein and Zeaxanthin and Their Roles in Age-Related Macular Degeneration—Neurodegenerative Disease

“…Carotenoids (L and Z) are thought to pre-filter blue light to reduce the adverse effects of glare disorders, light scattering, and chromatic aberration, thus optimizing contrast sensitivity. Macular pigments act as filters in that they improve vision by increasing both the contrast of objects and their background [33][34][35]. Stringham et al [33] reported that supplementation with a macular carotenoid product increased contrast sensitivity, improving glare incapacity.…”