Glutathione (2000, '02, '11, '13, '15, '17) & Cataract
Learn more about cataracts.
The following and other studies demonstrating the effectiveness of glutathione as a powerful anti-oxidant are also important with respect to macular degeneration and other eye diseases.
Furthering the understanding that glutathione is an essential antioxidant for healthy lenses, researchers in India compared glutathione and argpyrimidine in healthy lenses from an eye lens bank and diseased lenses (both nuclear and cortical) that had been removed during cataract surgery.
They found that glutathione levels were significantly lower in lenses with cataracts compared to healthy lenses. In addition they found that glutathione levels were even lower in nuclear cataract lenses compared to cortical cataract lens.
Argpyrimidine is a biochemical that is formed in the presence of sugars, a process known as glycation. Argpyrimidine levels were much higher in the diseased lenses.
Editor's Note: It's well established that diabetics, who are unable to properly process sugars, have a greater risk of developing cataracts.
Mynampati, B.K., Ghosh, S., Muthukumarappa, T, Ram, J. (2017). Evaluation of antioxidants and argpyrimidine in normal and cataractous lenses in north Indian population. Int J Ophthalmol, 10(7): 1094–1100.
Polymorphisms, abnormal changes, to glutathione found in the body have been associated with increased cataract risk.
The researchers did a meta-analysis - a study of the studies that have been done - to determine the degree of accuracy in this assumption.
They evaluated the results of a total of 24 different studies that had investigated the relationship between several types of changes (GSTM1 and GSTT1) using what is known as a random-or fixed-effects model.
They found that GSTM1 null polymorphism was not associated with increased cataract risk, but that GSTT1 null was markedly tied to a particular type of cataract - posterior subcapsular - which occurs more often in patients of Asian peoples. Further investigation is needed.
Researchers: W. Sun, et al.
Published: Is there association between Glutathione S Transferases polymorphisms and cataract risk: a meta-analysis? BMC Ophthalmology, July, 2015.
Other researchers have tied low levels of glutathione in the body with formation of cataracts. Such low levels are associated with oxidation of crystallins in the lens. In order to further understand the process by which this occurs researchers compared human cataracts with cataracts from lab animals which had been caused by low levels of glutathione.
They found that a certain type of molecular bond (disulfide bond) were prominent in crystallins at young humans and in healthy mouse lenses. But at an older age in humans and in the mouse lenses that had formed cataracts a different type of molecular bond was prevalent (multimeric intermolecular disulfide bond).
Researchers: X. Fan, et al.
Published: Evidence of highly conserved beta-crystallin disulfidome that can be mimicked by in vitro oxidation in age-related human cataract and glutathione depleted LEGSKO mouse lens, Molecular Cell Proteomics, Oct. 2015.
There is a link between childhood cataract and glutathione depletion in maternal malnutrition.
Kumar, D., Lim, J.C., Donaldson, P.J. (2013). A link between maternal malnutrition and depletion of glutathione in the developing lens: a possible explanation for idiopathic childhood cataract? Clin Exp Optom, Nov;96(6):523-8.
The importance of vitamin C to eye health cannot be understated; concentrations of vitamin C in the lens are 20–30 times higher than those in the plasma. Vitamin C doesn’t work alone: it needs glutathione to improve the use of ascorbic acid (the purist form of vitamin C) in the body. Glutathione and vitamin C are thought to work together to promote proper water balance within the lens and prevent the protein clumping that can lead to cataracts.
Ravindran, R.D., Vashist, P., Gupta S.K., Young, I.S., Maraini, G., et al. (2011). Inverse Association of Vitamin C with Cataract in Older People in India. Ophthalmology, Oct;118(10):1958-1965.
Researchers find that older people had a greater drop in glutathoine blood status than younger people with a corresponding increase in oxidized glutathione by-product over time suggests more oxidation and the higher risk of age-related eye diseases.
Researchers: S. P. Ayalasomayajula, et al.
Published: Induction of vascular endothelial growth factor by 4-hydroxynonenal and its prevention by glutathione precursors in retinal pigment epithelial cells. European Journal of Pharmacology, August, 2002
Researchers have demonstrated that glutathione (GSH) is an essential antioxidant which is particularly concentrated in the lens of the eye. It detoxifies oxidants (free-radicals) such as H202 and dehydroascrobic acid. When there are very low levels of GHS in the lens, it has been found that even low levels of oxidants can damage the lens.
Study 1: F. J. Giblin, et al., Glutathione: a vital lens antioxidant. Journal Ocular Pharmacological Therapies, April 2000
Study 2: R.F. Brubaker, et al., Ascorbic acid content of human corneal epithelium. Investigative Ophthalmology & Visual Science, June, 2000
Also see oxidative stress and cataract for more information on 2013 glutathione research.