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Zeaxanthin Research

Friday, January 21, 2011


Thanks to the unbridled passion for zeaxanthin science of our friend and fellow member/supporter of the Ocular Nutrition Society and the Council for Responsible Nutrition, Dennis Gierhart, PhD, the ophthalmic community better understands the important role that zeaxanthin plays in neural tissue health.

Supplementing with zeaxanthin has been suggested in a number of clinical studies to lower the risk of diseases associated with aging, including macular degeneration and cataract. Science also suggests that zeaxanthin can efficiently inhibit diabetes-induced lipid peroxidation in the retina. 

We have known for a number of years that zeaxanthin protects the eye from ultraviolet and blue-light damage. Zeaxanthin's ability to absorb blue light was recently found to make night driving easier for older adults who participated in a carotenoid  study that looked at supplementation with lutein and zeaxanthin; lutein alone, and zeaxanthin alone.    
 
Zeaxanthin and lutein are the two carotenoids responsible for the macula pigment, with zeaxanthin being in the very center of the macula.  Both nutrients are included in two arms of the AREDs2 study: 10 mg of lutein and 2 mg of zeaxanthin.  However, the amount of zeaxanthin included is less than optimal, given the very promising research that supports higher dosage of zeaxanthin to be beneficial for a number of diseases of the eye.
 
A research study published in Investigative Ophthalmology and Visual Science (IOVS), suggests that zeaxanthin supplementation prevented diabetes-induced increase in retinal damage, and it prevented increases in vascular endothelial growth factor (VEGF), and intercellular adhesion molecule (ICAM-1).
 
Diabetic retinopathy is considered to be a multifactorial disease with various abnormalities contributing to its development. It is the major cause of blindness in young adults.  VEGF, a major angiogenic factor is elevated in the retina and vitreous of diabetic patients and animals, and this increase is associated with the manifestation of diabetic retinopathy. 
 
Oxidative stress is always increased in the retina in diabetes; the antioxidant defense system is compromised, and superoxide levels are elevated in the mitochondria.  Increased oxidative stress is one of the key regulators in the development of diabetic complications. Antioxidants are suggested to prevent diabetes-induced oxidative stress and the development of retinopathy in research animals and people.
 
Diabetics have lower serum levels of the xanthophyll carotenoids, zeaxanthin and lutein, and they also seem to have lower serum levels of the hydrocarbon carotenoid, lycopene. Their retinal levels of zeaxanthin and lutein are also decreased.
 
Zeaxanthin is generally considered a safe supplement (GRAS).  Although Zeaxanthin is available from a few foods including corn, egg yolks, paprika, oranges and green vegetables, the daily consumption is far lower than the concentration necessary for ocular/neural tissue protection.
 
Ellen Troyer, MT MA
Biosyntrx CEO / Chief Research Officer

PEARL

Due to the impressive growing body of zeaxanthin research and customer pressure, Biosyntrx brought Zeaxanthin4 back into our product line in early 2010. Each capsule includes 4 mg of zeaxanthin (as natural ZeaGold from U.S. grown paprika peppers) in a base of 25 mg of fat soluble vitamin C.  It is designed to be a cost-effective formula for those patients who choose to supplement with zeaxanthin as a stand alone carotenoid. The suggested retail cost of 180 capsules of Zeaxanthin4 is now $24.95.
 
Addendum:  A study published in the January 2010 edition of the European Journal of Nutrition, Competitive inhibition of carotenoid transport and tissue concentrations by high dose supplements of lutein, zeaxanthin and beta-carotene, concluded that high dose dietary supplementation of a single carotenoid may alter the assimilation of other carotenoids. The study authors also concluded that the retina has the capacity to preserve accumulation of lutein and zeaxanthin, but this capacity is diminished when intake of beta-carotene is high. Both eye care practitioners and consumers need to keep this in mind when recommending or purchasing ocular-specific nutritional formulations that include excessive amounts of beta carotene.


 A STARK WARNING:  Smoking Causes Genetic Damage.  This report was released in the most recent  peeer-reviewed journal, Chemical Research in Toxicology.  The article is posted in this week's Biosyntrx blog. http://biosyntrx.blogspot.com/   

Crestpoint Management, LTD instrument announcement:
Jones Inamura Capsulorhexis Forceps 2-2-716G-10

References

Beneficial Effect of Zeaxanthin on Retinal Metabolic Abnormalities in Diabetic Rats. Kowluru R, Menon B, Gierhart D. IOVS April 2008;49:1645-1651 [abstract]
 
The value of measurement of macular carotenoid pigment optical densities and distributions in age-related macular degeneration and other retinal disorders. Bernstein, P, Delori F, Richer S, et al. Vision Research, Oct 23, 2009 [abstract]
 
Plasma carotenoids and diabetic retinopathy. Brazionis L, Rowley K, Itwsiopoulos C, O'Dea K. Br J Nutr. 2008 Jun 13:1-8 [abstract]
 
Nutrition and retina. Schmidt-Erfurth U. Dev Ophthalmol. 2005;38;120-47 [abstract]
 
The pathobiology of diabetic complications: a unifying mechanism. Diabetes. Brownlee M. 2005;54:16151625. [Medline]
 
Diabetes mellitus and serum carotenoids: findings of a population-based study in Queensland, Australia. Coyne T, Ibiebele TI, Baade PD, et al. Am J Clin Nutr. 2005;82:685693. [Abstract/ Free Full Text]
 
 Macular pigment: a review of current knowledge. Whitehead AJ, Mares JA, Danis RP.Arch Ophthalmol. 2006;124:10381045. [Abstract/ Free Full Text]
 
Lutein and Zeaxanthin measured separately in the living human retina with fundus reflectometry. van de Kraats J, Kanis MJ, Generrs SW, van Norren D. IOVS 2008 Aug 1 [abstract]
 
Elevated retinal zeaxanthin and prevention of light-induced photoreceptor cell death in quail. Thomson LR, Toyoda Y, Langner A, et al. Invest Ophthalmol Vis Sci. 2002;43:35383549. [Abstract/ Free Full Text]
 
The retinal carotenoids zeaxanthin and lutein scavenge superoxide and hydroxyl radicals: a chemiluminescence and ESR study. Trevithick-Sutton CC, Foote CS, Collins M, Trevithick JR. Mol Vis. 2006;12:11271135. [Medline]
 
Relationships of circulating carotenoid concentrations with several markers of inflammation, oxidative stress, and endothelial dysfunction: the coronary artery risk development in young adults (CARDIA)/Young Adult Longitudinal Trends in Antioxidants (YALTA) Study. Hozawa A, Jacobs DR. et al.  Clin Chem. 2007;53:447455. [Abstract/ Free Full Text]
 
A central role for inflammation in the pathogenesis of diabetic retinopathy. Joussen AM, Poulaki V, Le ML, et al. FASEB J. 2004;18:14501452. [Abstract/ Free Full Text]
 
Competitive inhibition of carotenoid transport and tissue concentrations by high dose supplements of lutein, zeaxanthin and beta-carotene. Wang Y, et al. Eur J Nutr. 2010 Jan 16 [abstract]