By Greg Arnold, DC, CSCS, July 21, 2009, abstracted from “Protective Effects of l- and d-Carnosine on α-Crystallin Amyloid Fibril Formation: Implications for Cataract Disease” in the 2009 issue of Biochemistry

Defined as "a clouding of the lens in the eye that affects vision", cataracts are the most common cause of blindness worldwide (1), affecting more than half of all Americans over the age of 80 (2).  More than 1.5 million cataract operations are performed each year in the U.S. alone (3), which cost our healthcare system over $3.4 billion each year (4).  

There are a number of ways to help maintain eye health, including superoxide dismutase (5), following a diet low on the glycemic index (6) and antioxidant supplementation (7).  Now a new lab study (8) has found that carnosine, a combination of two amino acids found in muscle tissue (alanine and histidine) that has been found to have antioxidant properties (9) and is even being looked at to help with schizophrenia (10), may also help eye health.

In the study, the researchers showed that two forms of carosine, l-carnosine and d-carnosine, in amounts of  0.1 Molar were able to prevent the buildup of a protein called alpha-crystallin in eye lens tissue taken from mice.  Alpha-crystallin buildup is a crucial step in the formation of cataracts (11).  The researchers noted that “inhibition of the formation of large [alpha-crystalin] fibers [was] clearly observed.”  In addition to preventing the buildup of the alpha-crystallin protein, the presence of carnosine even broke down existing alpha-crystalin proteins and “restor[ed] almost completely the lens transparency.”

When suggesting how carnosine exhibits these effects on alpha-crysatlin, the researchers point to previous research showing carnosine’s antioxidant properties in its ability to keep levels of nitric oxide low, since high levels of nitric oxide is also a characteristic of cataracts (12).  These results led the researchers to conclude that carnosine “can be a valuable therapeutic tool” in helping maintain eye health.

Greg Arnold is a Chiropractic Physician practicing in Danville, CA.  You can contact Dr. Arnold directly by emailing him at mailto:PitchingDoc@msn.com or visiting his web site at www.CompleteChiropracticHealthcare.com

Reference:

1. Foster A, Johnson GJ. Magnitude and causes of blindness in the developing world. Int Ophthalmol 1990;14:135-40
2. National Eye Institute Website
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4. Steinberg EP, Javitt JC, Sharkey PD, et al. The content and cost of cataract surgery. Arch Ophthalmol 1993; 111: 1041–9
5. Reddy VN.  SOD2 Protects against Oxidation-Induced Apoptosis in Mouse Retinal Pigment Epithelium: Implications for Age-Related Macular Degeneration.  Invest. Ophthalmol. Vis. Sci. 2005 46: 3426-3434
6. Chiu CJ.  Dietary carbohydrate intake and glycemic index in relation to cortical and nuclear lens opacities in the Age-Related Eye Disease Study.  Am. J. Clinical Nutrition, May 2006; 83: 1177 – 1184
7. Chylack, L.T., Jr., et al., The Roche European American Cataract Trial (REACT): a randomized clinical trial to investigate the efficacy of an oral antioxidant micronutrient mixture to slow progression of age-related cataract. Ophthalmic Epidemiol, 2002. 9(1): p. 49-80
8. Attanasio F.  Protective Effects of l- and d-Carnosine on α-Crystallin Amyloid Fibril Formation: Implications for Cataract Disease.  Biochemistry, 2009, 48 (27), pp 6522–6531
9. Kang, J. H., Kim, K. S., Choi, S. Y., Kwon, H. Y., Won, M. H. and Kang, T. C. ( 2002) Protective effects of carnosine, homocarnosine and anserine against peroxyl radical-mediated Cu,Zn-superoxide dismutase modification Biochim. Biophys. Acta 1570, 89– 96
10. “L-Carnosine for Schizophrenia” posted on http://clinicaltrials.gov/ct2/show/NCT00177177
11. Sun, Y. and MacRae, T. H. ( 2005) The small heat shock proteins and their role in human disease FEBS J. 272, 2613– 2627
12. Nicoletti, V. G., Santoro, A. M., Grasso, G., Vagliasindi, L. I., Giuffrida, M. L., Cuppari, C., Purrello, V. S., Giuffrida-Stella, A. M. and Rizzarelli, E. ( 2007) Carnosine interaction with nitric oxide and astroglial cell protection J. Neurosci. Res. 85, 2239– 2245