Eye-opening Zeaxanthin This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to: Frankp@chiro.org
From June 2001 Issue of Nutrition Science News
by Anthony AlmadaSeemingly from out of the dark came the carotenoid lutein, which offers the hope of preventing ocular diseases such as age-related macular degeneration (AMD) and cataracts, and may improve visual function. [1] However, placing the spotlight on lutein alone may be myopic. Its rose-colored cousin, zeaxanthin, is also richly concentrated in the eye and, unlike lutein, is more elusive in the diet. [2]
Both carotenoids reside in the retina's macular pigment, which is colored largely by dietary lutein and zeaxanthin. A recent study with human eyes from postmortem donors revealed a specific protein that selectively binds lutein and zeaxanthin, [3] explaining why they are predominant in the macular pigment. Another study on 55 individuals from northwest England, with either healthy eyes or AMD in one eye, found macular pigment decreases across age groups, and is lower in the healthy eye of subjects with AMD in the other eye. [4 ]
Zeaxanthin is abundant in lycii berry fruit (Lycium barbarum), [5] spinach, spirulina, [6] and other commercially produced algae. What remains to be seen is whether supplementation with zeaxanthin/lutein (zeaxanthin occurs in greater concentrations than does lutein) [7] produces functional improvement in vision and alters the course of AMD and cataracts.
Anthony Almada is a nutritional and exercise biochemist and has collaborated on more than 50 university-based clinical trials. He is the co-founder of EAS and founder and chief scientific officer of IMAGINutrition.
He is also is a consultant to both a producer of spirulina and a producer of an algal source of zeaxanthin.
References
Hammond BR, et al. Carotenoids in the retina and lens: possible acute and chronic effects on human visual performance.
Arch Biochem Biophys 2001;385:41-6.
Yemelyanov AY, et al. Ligand-binding characterization of xanthophyll carotenoids to solubilized membrane proteins derived from human retina.
Exp Eye Res (published online in March, prior to print in 2001).
Landrum JT, et al. Lutein, zeaxanthin, and the macular pigment.
Arch Biochem Biophys 2001;385:28-40.
Beatty S, et al. Macular pigment and risk for age-related macular degeneration in subjects from a northern European population.
IOVS 2001;42:429-46.
Leung IYF, et al. Absorption and tissue distribution of zeaxanthin and lutein in rhesus monkeys after taking Fructus lycii (Gou Qi Zi) extract.
IOVS 2001;42:466-71.
Careri M, et al. Supercritical fluid extraction for liquid chromatographic determination of carotenoids in Spirulina Pacifica algae: a chemometric approach.
J Chromatogr 2001;912:61-71
Bernstein PS, et al. Identification and quantitation of carotenoids and their metabolites in the tissues of the human eye. Exp Eye Res 2001;72:215-23
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