Zeaxanthin

Role of lutein and zeaxanthin in visual and cognitive function throughout the lifespan.[Pubmed:25109868]

Nutr Rev. 2014 Sep;72(9):605-12.

The relationship between lutein and Zeaxanthin and visual and cognitive health throughout the lifespan is compelling. There is a variety of evidence to support a role for lutein and Zeaxanthin in vision. Lutein's role in cognition has only recently been considered. Lutein and its isomer, Zeaxanthin, are taken up selectively into eye tissue. Lutein is the predominant carotenoid in human brain tissue. Lutein and Zeaxanthin in neural tissue may have biological effects that include antioxidation, anti-inflammation, and structural actions. In addition, lutein and Zeaxanthin may be protective against eye disease because they absorb damaging blue light that enters the eye. In pediatric brains, the relative contribution of lutein to the total carotenoids is twice that found in adults, accounting for more than half the concentration of total carotenoids. The greater proportion of lutein in the pediatric brain suggests a need for lutein during neural development as well. In adults, higher lutein status is related to better cognitive performance, and lutein supplementation improves cognition. The evidence to date warrants further investigation into the role of lutein and Zeaxanthin in visual and cognitive health throughout the lifespan.

A randomized placebo-controlled study on the effects of lutein and zeaxanthin on visual processing speed in young healthy subjects.[Pubmed:25483230]

Arch Biochem Biophys. 2015 Apr 15;572:54-57.

Speed of processing is a particularly important characteristic of the visual system. Often a behavioral reaction to a visual stimulus must be faster than the conscious perception of that stimulus, as is the case with many sports (e.g., baseball). Visual psychophysics provides a relatively simple and precise means of measuring visual processing speed called the temporal contrast sensitivity function (tCSF). Past study has shown that macular pigment (a collection of xanthophylls, lutein (L), meso-Zeaxanthin (MZ) and Zeaxanthin (Z), found in the retina) optical density (MPOD) is positively correlated with the tCSF. In this study, we found similar correlations when testing 102 young healthy subjects. As a follow-up, we randomized 69 subjects to receive a placebo (n=15) or one of two L and Z supplements (n=54). MPOD and tCSF were measured psychophysically at baseline and 4months. Neither MPOD nor tCSF changed for the placebo condition, but both improved significantly as a result of supplementation. These results show that an intervention with L and Z can increase processing speed even in young healthy subjects.

Lutein and zeaxanthin toxicity with and without brilliant blue in rabbits.[Pubmed:24901374]

J Ocul Pharmacol Ther. 2014 Sep;30(7):559-66.

PURPOSE: To evaluate the safety profile of solutions containing lutein and Zeaxanthin alone or associated with brilliant blue (BB). METHODS: Twenty-eight New Zealand rabbits were used to evaluate 4 concentrations of the various dye solutions: 0.5% lutein/Zeaxanthin; 0.5% lutein/Zeaxanthin associated with 0.0125% BB; 0.3% lutein/Zeaxanthin associated with 0.025% BB; and 0.25% lutein/Zeaxanthin associated with 0.05% BB. The pHs of the dye solutions ranged from 6.5 to 7.2 and the osmolarities from 280 to 320 mOsm/mL. Each rabbit had 0.1 mL of one of the dyeing solutions injected into the vitreous cavity of the right eye, while balanced salt solution (BSS) was injected into the left eye as the control. Scotopic electroretinography responses were recorded in all eyes at different time points. The animals were sacrificed at 1 and 7 days after injection; the eyes were analyzed by light and transmission electron microscopy. RESULTS: No significant (P>0.05) differences were seen in the a- and b-wave amplitudes among groups at any given point in time. Light and electron microscopy findings showed no significant abnormalities either, and were similar to the histological findings after intravitreal BSS injection. CONCLUSIONS: Lutein and Zeaxanthin alone or in association with BB showed a good safety profile in this experimental model.

Safety evaluation of zeaxanthin concentrate (OmniXan): acute, subchronic toxicity and mutagenicity studies.[Pubmed:24964014]

Food Chem Toxicol. 2014 Oct;72:30-9.

The available evidence suggests a beneficial effect of Zeaxanthin against the progression of age-related macular degeneration (AMD). The objective of the present study was to investigate potential adverse effects of OmniXan, a RR-Zeaxanthin (65%) enriched product obtained from paprika (Capsicum annum fruits) in subchronic toxicity and mutagenicity studies. The oral LD50 of OmniXan(TM) in rats was greater than 2000 mg/kgbody weight (bw)/day. For the subchronic toxicity study, Wistar rats (10/sex/group) were gavaged daily with Zeaxanthin concentrate at doses of 0, 4, 40 and 400 mg/kg bw/day for 90-days. No treatment related clinical signs and mortalities observed. Similarly, no treatment related toxicologically significant changes in body weight, feed consumption; ophthalmoscopic examination, neurological examination, hematology, urine analysis and organ weights were observed. Statistically significant changes observed in some clinical chemistry parameters were considered toxicologically and biologically insignificant and nonadverse. Macroscopic and microscopic examinations did not reveal treatment-related abnormalities. The results of mutagenicity testing using Salmonella typhimurium did not reveal any genotoxicity. The no observed-adverse-effect level (NOAEL) for Zeaxanthin concentrate (OmniXan(TM)) was determined as 400 mg/kg bw/day, the highest dose tested. The findings of this subchronic toxicity and mutagenicity studies support safety of Zeaxanthin concentrate.