Amino acids play a critical role in healthy vision. Amino acids function as protein building blocks,
wherein they act as catalysts in the metabolic process. Without adequate metabolism nutrients that are included
in foods are not available to the body. By way of example, one set of proteins, known as ciliary opsins, are
found in photoreceptors that convert light energy to nerve impulses. One type of ciliary opsin is rhodopsin,
needed for maintaining night vision.
Cysteine
Cysteine, consumed as N-acetyl-cysteine (NAC) helps your retina stay healthy by increasing the production of the potent antioxidant glutathione. The body can synthesize glutathione from amino acids, but cysteine is the one component essential for glutathione production in the body that is not commonly found in foods. Glutathione is one of the "super" antioxidants used throughout the body, and is considered one of the essential anti-aging nutrients.
Taurine. In the healthy eye, high levels of this nutrient are found in the retina. Taurine is essential for
the regeneration and elimination of worn-out visual system tissue, as well as being a potent antioxidant. While it is located everywhere in the body
it is especially found in nerve (retina and inner ear) and muscle tissue. It's been noted that populations who naturally consume higher levels of taurine have longer lifespans.
Patients with diabetes have an increased need for taurine - taurine levels are lower in diabetics, and research indicates that the relationship
between low levels of taurine, obesity, and diabetes is a close one.1 Taurine levels are also tied to non-alcoholic fatty liver
disease,2 cardiovascular disease,3 and possibly tinnitus.4
1. Franconi F, et al., Plasma and platelet taurine are reduced in subjects with insulin-dependent diabetes mellitus: effects of taurine supplementation, American Journal of Clinical Nutrition,1995 May;61(5):1115-9.
2. Miyazaki T, et al, The protective effect of taurine against hepatic damage in a model of liver disease and hepatic stellate cells, Advances in Experimental Medicine and Biology 2009;643:293-303.
3. Murakami S., Taurine and atherosclerosis. Amino Acids, December 8, 2012.
4. Liu HY, et al, Taurine modulates calcium influx through L-type voltage-gated calcium channels in isolated cochlear outer hair cells in guinea pigs. Neuroscience Letters 2006 May 15;399(1-2):23-6.