• ]]>Atherosclerosis]]>, ]]>Cataracts]]>, ]]>Macular Degeneration]]>, ]]>Retinitis Pigmentosa]]>
Lutein, a chemical found in green vegetables, is a member of a family of substances known as ]]>carotenoids]]> . ]]>Beta-carotene]]> is the most famous nutrient in this class. Like beta-carotene, lutein is an ]]>antioxidant]]> that protects our cells against damage caused by dangerous, naturally occurring chemicals known as free radicals.
Recent evidence has found that lutein may play an important role in protecting our eyes and eyesight. It may work in two ways: by acting directly as a kind of natural sunblock, and also by neutralizing free radicals that can damage the eye.
Lutein is not an essential nutrient. However, it is possible that it may be useful for optimal health.
Green vegetables are the best source of lutein, especially spinach, kale, collard greens, romaine lettuce, leeks, and peas. Unlike beta-carotene, lutein is not found in high concentrations in yellow and orange vegetables such as carrots.
We don't know how much lutein is necessary for a therapeutic effect, but estimates range from 5 to 30 mg daily. (However, see Safety Issues]]> .)
According to theoretical findings and two preliminary double-blind studies, it appears that use of lutein supplements might help prevent or slow the development of age-related macular degeneration]]> (ARMD) and possibly ]]>cataracts]]> , the two most common causes of vision loss in seniors.
What is the Scientific Evidence for Lutein?
Most but not all ]]>observational]]> studies suggest that people who eat foods containing lutein are less likely to develop cataracts and perhaps macular degeneration as well, the two most common causes of vision loss in adults. ]]>1-5,8]]> Furthermore, there are good theoretical reasons to believe that lutein may play an important role in protecting the eyes.
Lutein is the main pigment (coloring chemical) in the center of the retina, the region of maximum visual sensitivity known as the macula . Macular degeneration consists of injury to the macula and leads to a severe loss in vision. One of the main causes of macular degeneration appears to be sun damage to the sensitive tissue. Lutein appears to act as a natural eyeshade, protecting the retina against too much light. ]]>6]]> It is also an ]]>antioxidant]]> , meaning that it fights dangerous, naturally occurring substances called free radicals. Free radicals may play a role in macular degeneration.
Based on this information, researchers conducted a ]]>double-blind, placebo-controlled]]> trial of lutein. ]]>11]]> The study enrolled 90 people with dry-type macular degeneration and followed them for 12 months. The participants received either lutein (10 mg), lutein plus other antioxidants, and a multivitamin/mineral supplement, or placebo. At the end of the study period, participants who had taken lutein alone or lutein plus the other nutrients showed improvements in vision, while no change in vision was seen in the placebo group.
A subsequent study failed to find benefit with lutein, but it used a lower dose (6 mg daily) and involved fewer people. ]]>15]]> Ultimately, further study will be needed to establish whether lutein is actually helpful for macular degeneration.
Besides protecting the macula, lutein might also shield the lens of the eye from light damage, slowing the development of ]]>cataracts]]> . ]]>7]]> One small 2-year, double-blind, placebo-controlled trial found some evidence that lutein may improve vision in people who already have cataracts. ]]>10]]>
Although lutein is a normal part of the diet, there has not been much evaluation of lutein's safety when taken as a concentrated supplement. One study found evidence that lutein is safe in doses up to the highest tested dose of 10 mg daily. 14]]> A review of other evidence concluded that long term use of lutein should be safe when taken at a dose of up to 20 mg per day. ]]>13]]>
Maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.
8. Mares-Perlman JA, Fisher AI, Klein R, et al. Lutein and zeaxanthin in the diet and serum and their relation to age-related maculopathy in the third National Health and Nutrition Examination Survey. Am J Epidemiol. 2001;153:424-432.
10. Olmedilla B, Granado F, Blanco I, et al. Lutein, but not alpha-tocopherol, supplementation improves visual function in patients with age-related cataracts: a 2-y double-blind, placebo-controlled pilot study. Nutrition . 2003;19:21-24.
11. Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry . 2004;75:216-30.
13. Bahrami H, Melia M, Dagnelie G, et al. Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial [NCT00029289]. BMC Ophthalmol. 2006 Jun 7. [Epub ahead of print]
15. Bartlett HE, Eperjesi F. Effect of lutein and antioxidant dietary supplementation on contrast sensitivity in age-related macular disease: a randomized controlled trial. Eur J Clin Nutr. 2007 Jan 31. [Epub ahead of print]
Last reviewed April 2009 by EBSCO CAM Review Board]]>
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