Lutein and Zeaxanthin


Lutein and Zeaxanthin


This page intends to be a space where you can find more information about the scientific studies and research tests proving the benefits from the use of the ingredients present in SOLEIL, this page is only for educational purposes, not expecting to promote our product. SOLEIL is a dietary supplement, that is, it’s not intended to treat, prevent, cure or mitigate any disease or any symptom.
It’s important to mention that discussion, results and conclusions from each study may not be supported by all scientists or no other researcher, sometimes there are opposition to the extension from benefits of that particular ingredient.

The antioxidant that is most well-known for protecting eye health, possess the abilities of helping to fight free radical that is caused by blue light or sun exposure.

In fact, there are more than 600 different types of carotenoids found in nature, but only about 20 make their way into the eyes. Of those 20, lutein and zeaxanthin are the only two that are deposited in high quantities into the macular portion of the eyes., a poor diet and other factors that increase the risk of developing age-related vision loss or ageing skin. In the process, antioxidants like lutein protect healthy cells while halting the growth of malignant cells.

In the text below you can find more information about the scientific studies that serve as background support to the benefits from the Lutein and Zeaxanthin usages.

CLINICAL RESEARCH PUBLICATIONS

Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes
ABSTRACT
It has been suggested that eating green leafy vegetables, which are rich in lutein and zeaxanthin, may decrease the risk for age related macular degeneration. The goal of this study was to analyse various fruits and vegetables to establish which ones contain lutein and/or zeaxanthin and can serve as possible dietary supplements for these carotenoids. Homogenates of 33 fruits and vegetables, two fruit juices, and egg yolk were used for extraction of the carotenoids with hexane. Measurement of the different carotenoids and their isomers was carried out by high performance liquid chromatography using a single column with an isocratic run, and a diode array detector. Egg yolk and maize (corn) contained the highest mole percentage (% of total) of lutein and zeaxanthin (more than 85% of the total carotenoids). Maize was the vegetable with the highest quantity of lutein (60% of total) and orange pepper was the vegetable with the highest amount of zeaxanthin (37% of total). Substantial amounts of lutein and zeaxanthin (30–50%) were also present in kiwi fruit, grapes, spinach, orange juice, zucchini (or vegetable marrow), and different kinds of squash. The results show that there are fruits and vegetables of various colours with a relatively high content of lutein and zeaxanthin.Most of the dark green leafy vegetables, previously recommended for a higher intake of lutein and zeaxanthin, have 15–47% of lutein, but a very low content (0–3%) of zeaxanthin. Our study shows that fruits and vegetables of various colours can be consumed to increase dietary intake of lutein and zeaxanthin.
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Biologic Mechanisms of The Protective Role of Lutein and Zeaxanthin in the Eye
ABSTRACT
The macular region of the primate retina is yellow in color due to the presence of the macular pigment, composed of two dietary xanthophylls, lutein and zeaxanthin, and another xanthophyll, meso-zeaxanthin. The latter is presumably formed from either lutein or zeaxanthin in the retina. By absorbing blue-light, the macular pigment protects the underlying photoreceptor cell layer from light damage, possibly initiated by the formation of reactive oxygen species during a photosensitized reaction. There is ample epidemiological evidence that the amount of macular pigment is inversely associated with the incidence of age-related macular degeneration, an irreversible process that is the major cause of blindness in the elderly. The macular pigment can be increased in primates by either increasing the intake of foods that are rich in lutein and zeaxanthin, such as dark-green leafy vegetables, or by supplementation with lutein or zeaxanthin. Although increasing the intake of lutein or zeaxanthin might prove to be protective against the development of age-related macular degeneration, a causative relationship has yet to be experimentally demonstrated.
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Lutein and Zeaxanthin as Protectors of Lipid Membranes against Oxidative Damage: The Structural Aspects
ABSTRACT
Two main xanthophyll pigments are present in the membranes of macula lutea of the vision apparatus of primates, including humans: lutein and zeaxanthin. Protection against oxidative damage of the lipid matrix and screening against excess radiation are the most likely physiological functions of these xanthophyll pigments in macular membranes. A protective effect of lutein and zeaxanthin against oxidative damage of egg yolk lecithin liposomal membranes induced by exposure to UV radiation and incubation with 2,2′-azobis(2-methylpropionamidine) dihydrochloride, a water-soluble peroxidation initiator, was studied. Both lutein and zeaxanthin were found to protect lipid membranes against free radical attack with almost the same efficacy. The UV-induced lipid oxidation was also slowed down by lutein and zeaxanthin to a very similar rate in the initial stage of the experiments (5–15 min illumination) but zeaxanthin appeared to be a better photo protector during the prolonged UV exposure. The decrease in time of a protective efficacy of lutein was attributed to the photooxidation of the carotenoid itself. Both lutein and zeaxanthin were found to slightly modify mechanical properties of the liposomes in a very similar fashion as concluded on the basis of H1 NMR and diffractometry measurements of pure egg yolk membranes and membranes pigmented with the xanthophylls. Linear dichroism analysis of the mean orientation of the dipole transition moment of the xanthophylls incorporated to the lipid multibilayers revealed essentially different orientation of zeaxanthin and lutein in the membranes. Zeaxanthin was found to adopt roughly vertical orientation with respect to the plane of the membrane. The relatively large orientation angle between the transition dipole and the axis normal to the plane of the membrane found in the case of lutein (67° in the case of 2 mol% lutein in EYPC membranes) was interpreted as a representation of the existence of two orthogonally oriented pools of lutein, one following the orientation of zeaxanthin and the second parallel with respect to the plane of the membrane. The differences in the protective efficacy of lutein and zeaxanthin in lipid membranes were attributed to a different organization of zeaxanthin–lipid and lutein–lipid membranes.
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Lutein and Zeaxanthin Dietary Supplements Raise Macular Pigment Density and Serum Concentrations of these Carotenoids in Humans
ABSTRACT
Age-related macular degeneration (AMD) is thought to be the result of a lifetime of oxidative insult that results in photoreceptor death within the macula. Increased risk of AMD may result from low levels of lutein and zeaxanthin (macular pigment) in the diet, serum or retina, and excessive exposure to blue light. Through its light-screening capacity and antioxidant activity, macular pigment may reduce photooxidation in the central retina. Lutein supplements, at 30 mg/d, were shown previously to increase serum lutein and macular pigment density in two subjects. In this study, we compared the effects of a range of lutein doses (2.4– 30 mg/d), as well as a high zeaxanthin dose (30 mg/d), on the serum and macular pigment in a series of experiments. Serum carotenoids were quantified by HPLC. Macular pigment densities were determined psychophysically. Serum lutein concentrations in each subject reached a plateau that was correlated with the dose (r = 0.82, P < 0.001). Plateau concentrations ranged from 2.8 × 10−7 to 2.7 × 10−6 mol/L. Zeaxanthin was less well absorbed than an equal lutein dose, resulting in plateaus of ∼5 × 10−7 mol/L. The rate of increase in macular pigment optical density was correlated with the plateau concentration of carotenoids in the serum (r = 0.58, P < 0.001), but not with the pre supplementation optical density (r = 0.13, P = 0.21). The mean rate of increase was (3.42 ± 0.80) × 105 mAU/d per unit concentration (mol/L) of carotenoids in the serum. It remains to be demonstrated whether lutein or zeaxanthin dietary supplements reduce the incidence of AMD.
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