Astaxanthin (2008, 2016, 2018) & Diabetic Retinopathy
Researchers have found that astaxanthin supplementation reduces cataract formation and diabetic retinopathy (both preventable forms of blindness in people with diabetes) in lab animals and has protective actions of microalgae against endogenous and exogenous advanced glycation end products (AGEs) in human retinal pigment epithelial cells.
Scientists are increasingly able to detect just why the carotenoids are helpful in diabetic eye disease. In this study lab animals with chemical-induced diabetic retinopathy exhibited improvement in a number of markers with even short-term astaxanthin supplementation. Blood samples had increased levels of a particular antioxidant enzyme (heme oxygenase-1,HO-1). In the retina structure certain biochemicals (cellular retinaldehyde binding protein and glutamine synthetase) were observed in the Müller cells.
Baccouche, B., Benlarbi, M., Barber A.J., Ben Chaouacha-Chekir, R. (2018). Short-Term Administration of Astaxanthin Attenuates Retinal Changes in Diet-Induced Diabetic Psammomys obesus. Curr Eye Res, Sep;43(9):1177-1189.
There are a number of types of damage that result from excessive glucose in the eyes: diabetic retinopathy (damage to the retina), diabetic nephropathy (damage to the kidneys), and diabetic neuropathy (damage to the nerves). They are different types of damage, but all result from the inability of the body to process sugar.
This review looks at the potential benefits of the carotenoids that are not precursors of vitamin A. Because they are not vitamins there is no recommended intake for them and thus they may be overlooked. They are lutein, zeaxanthin, lycopene, and astaxanthin. All are able to reduce oxidative stress, inflammation (which affects pancreas dysfunction and reduced insulin sensitivity).
Astaxanthin is thought to be 10 times more powerful than other "eye-beneficial" compounds such as beta-carotene. Astaxanthin is helpful in diabetic complications due to its antioxidant capacity which fights free radicals and reduces oxidative stress causing inflammation.
Astaxanthin and other carotenoids appear to be helpful in diabetic retinopathy but there is not enough research to unqualifiedly claim that; however it should be an important part of the diabetics diet along with other substances that help to control glucose levels.
Murillo, A.G., Fernandez, M.L. (2016). Potential of Dietary Non-Provitamin A Carotenoids in the Prevention and Treatment of Diabetic Microvascular Complications. Adv Nutr, Jan 15;7(1):14-24.
This study investigated the use of astaxanthin along with flavangenol (french maritime pine bark) in alleviating diabetic retinopathy in lab animals. The researchers found that the combination is more effective than either nutrient alone, and that each nutrient is better than no supplementation in the controls.
Nakano, M., Orimo, N., Katagirim N., Tsubata, M., Takahashi, J., et al. (2008) Inhibitory effect of astaxanthin combined with flavangenol on oxidative stress biomarkers in streptozotocin-induced diabetic rats. Int J Vitam Nutr Res, 2008 Jul-Sep;78(4-5):175-82.