Glutathione ('00, '11, '13, '14, '18) & Diabetic Retinopathy
It is now well established that high levels of free radicals (reactive oxygen species) are present in diabetics, as a result of reduced and/or compromised antioxidants in the body such as glutathione.
Santiago, A.R., Boia, R., Aires, I.D., Ambrosio, A.F. and Fernandes, R. (2018). Sweet Stress: Coping with Vascular Dysfunction in Diabetic Retinopathy. Front Physiol, 2018;9:820.
One of the therapeutic approaches to managing diabetes mellitus and preventing onset of complications like diabetic retinopathy is that of attention to reducing oxidative stress through the antioxidants like glutathione, carotenoids (like lutein and zeaxanthin), and other antioxidants like lipoic acid.
Safi, S.Z., Qvist, R., Kumar, S., Batumalaie, K. and Ismail, I.S.B. (2014). Molecular Mechanisms of Diabetic Retinopathy, General Preventive Straties, and Novel Therapeutic Targets. Biomed Red Int., 2014:801269.
Researchers investigated the differences and relationship between glutathione levels and different forms of insulin-related difficulties. They compared patients with type 2 diabetes, impaired glucose tolerance, and people normal fasting glucose blood levels with respect to glutathione levels. The patients with diabetes had the lowest levels of glutathione. (Note. Glutathione levels also decrease with aging). The researchers concluded that glutathione deficiency was a significant factor in the development of diabetes. High blood sugar levels (hyperglycemia causes oxidative stress and glutathione's ability to reduce free radicals appears to be at least part of the reason for improvement.Kalkan, I.H., Suher, M. (2013). The relationship between the level of glutathione, impairment of glucose metabolism and complications of diabetes mellitus. Pak J Med Sci, 29(4):Jul-Aug.
Glutathione is one of the super antioxidants that neutralizes the full range of free radicals. Patients with uncontrolled type 2 diabetes are unable to adequately synthesize glutathione because of a lack of natural precursors in the body. Supplementing with amino acids, which are GSH precursors, supports GSH synthesis and reduces oxidative damage and inflammation.
Sekhar, R.V., McKay, S.V., Patel, S.G., Guthikonda, A.P. Reddy, V.T., et al. (2011). Glutathione Synthesis Is Diminished in Patients With Uncontrolled Diabetes and Restored by Dietary Supplementation With Cysteine and Glycine. Diabetes Care, Jan; 34(1):162–167.
Researchers noted that free radicals forming in diabetes patients which accumulate with time may contribute to the development of diabetic retinopathy.
Gurler, B., Vural, H., Yilmaz, N., Oguz, H., Satici, A., et al. (2000). The role of oxidative stress in diabetic retinopathy. Eye (Lond), Oct;14 Pt 5:730-5.