Lutein
Lutein is essential for vision health. It does not directly function in the process of sight. Rather, it is a powerful antioxidant that protects the macula by absorbing damaging blue, violet and ultra violet light. It accumulates in the retina including at the macula, the oval-shaped pigmented area near the center of the retina, which is responsible for detail vision. The macula is yellow because of the yellow color of lutein (and zeaxanthin); and it is the yellow pigment that is able to absorb oxidizing blue, violet and ultra violet light.
Lutein has been shown to lessen the risk of severe damage from age-related macular degeneration. Researchers have noted that diets rich in lutein reduce the risk of developing AMD by 57%.1 They found that treatment with lutein helped to thicken the protective pigmented layer of the retina.2 And they found that retinas with AMD had 30% less lutein than healthy retinas.3
Lutein is even more effective when coupled with other carotenoids zeaxanthin and mesozeaxanthin.15 Lutein has also been shown to reduce the risk of progression (by 25-30%) of the dry (early) form of macular degeneration into the more severe (wet) form which is also known as choroidal neovascularization.4
Eye disease Lutein is also somewhat helpful in preventing and managing cataracts,5, 6 central serous chorioretinopathy,7 and uveitis.8
Macular degeneration. Abundant research has brought use of these phytonutrients into the mainstream of vision care. The landmark studies which came to the attention of many conventional eye doctors were the AREDS studies. There were two studies and an update, all tied to the Age-Related Eye Disease Study. AREDS (2001), AREDS2 (2006) and the AREDS update in 2013 laid out protocols for macular degeneration treatment that included carotenoids, vitamins and omega-3 fatty acids.9
Immune response. Lutein is more than merely a filter for the sun's UV radiation. 2012 research has shown that it modulates immune responses as well as inflammation, including inflammation in the eye such as that is manifested in uveitis, laser-induced choroidal neovascularization, retinal ischemia and diabetic retinopathy.10
Biomarker Role. In 2016 researchers identified lutein as one of the carotenoids that makes an excellent biomarker in observing women's dietary intake. In other words, the levels of lutein in the blood indicate the degree to which nutrients are actually being absorbed by the body and being used by cell tissue.11 Generally, biomarkers are used as tools in diagnosing disease.
Atherosclerosis. Lutein may also be helpful in fighting atherosclerosis by improving circulation. Researchers found that lutein levels in the blood are tied to artery wall thickness,12, 13 and may help to reduce accumulation of plaque by preventing oxidation of fats in the bloodstream.14
Food sources: The best source of lutein is kale, and then spinach. Other good sources of lutein include turnip greens, summer squash, brussels sprouts, orange foods such as corn, pumpkin, paprika, yellow-fleshed fruits, pecans and avocado. Note: The lutein that comes from red/orange fruits and foods support macular pigment density more than those from green vegetables.15 Also, a small study found that lutein from enriched eggs was absorbed more easily than lutein from spinach or supplements.15
Daily need: 6-20mg daily.
Caution: People with cystic fibrosis may not absorb lutein from supplements very well.
Lutein News
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Footnotes
1. Seddon, J.M., U.A. Ajani, et al, (1994). Dietary carotenoid, vitamins A, C, E, and advanced age-related macular degeneration. J AMA.
2. J.T. Landrum, et al. (1997). The Macular Pigment: A Possible Role in Protection from Age-Related Macular Degeneration. Adv Pharmacol. 38:537-556.
3. Ibid. Landrum.
4. Ibid. Landrum.
5. B. Olmedill, et al. (2003). Lutein, but not alpha tocopherol, supplementation improves visual function in patients with age-related cataracts: A 2 year double-blind, placebo
controlled study. Nutrition
6. Manayi. A. et al, (2015). Lutein and cataract: from bench to bedside. Crit Rev Biotech. Jun.
7. Sawa, M., Gomi, F., et al. (2014). Effects of a lutein supplement on the plasma lutein concentration and macular pigment in patients with central serous chorioretinopathy.
Invest Ophthal Vis Sci. Jul.
8. He, R.R., Tsoi, B., et al. (2011). Antioxidant properties of lutein contribute to the protection against lipopolysaccharide-induced uveitis in mice. Chinese Medicine. Oct.
9. AREDS, AREDS2: (2001, 2006, 2013) Antioxidants & Macular Degeneration. Retrieved from https://www.naturaleyecare.com/study.asp?s_num=105.
10. Kijlstra, A., et al. (2012). Lutein: more than just a filter for blue light. Prog Ret Eye Res. Jul.
11. Lampe, J.W., et al. (2016). Dietary biomarker evaluation in a controlled feeding study in women from the Women's Health Initiative cohort. Am J Clin Nutri. Dec.
12. Dwyer, J.H., et al. (2001). The Los Angeles Atherosclerosis Study, Oxygenated Carotenoid Lutein and Progression of Early Atherosclerosis. Circulation. Jun.
13. Zou, Z., Hu, X., Huang, Y. et al. (2011). High serum level of lutein may be protective against early atherosclerosis: the Beijing atherosclerosis study. Athero. Dec.
14. Howard, A.N., Thurnham, D.I. (2017). Lutein and atherosclerosis: Belfast versus Toulouse revisited. Med Hypo. Jan.
15. Chung H.Y., Rasmussen H.M., Johnson E.J. (2004) Lutein bioavailability is higher from lutein-enriched eggs than from supplements and spinach in men. J Nutr. Aug;134(8):1887-93.
16. SanGiovanni, J.P., Chew, E.Y., Clemons, T.E., et al. (2007). The relationship of dietary carotenoid and vitamin A, E, and C intake with age-related macular degeneration in a case-control study:
AREDS Report No. 22. Arch. Ophthalmol. 125 (9): 1225-32.