Lutein May Protect against Blindness
July 6, 2006—An antioxidant found in spinach and kale may protect against a common cause of blindness. Researchers at Johns Hopkins University have found that lutein, a carotenoid, helps preserve the visual field in people with retinitis pigmentosa.
“There is no generally accepted medical or surgical treatment to stop the progressive course of retinitis pigmentosa,” said Gislin Dagnelie, PhD, an associate professor of ophthalmology at the Johns Hopkins University School of Medicine. “Since lutein is important to the health of the retina, we sought to determine if it could improve vision, or at least slow down the course of this serious form of retinal degeneration.”
Retinitis pigmentosa refers to a diverse group of hereditary diseases of the retina in which light receptors degenerate. It affects 1 in every 4,000 to 5,000 people worldwide.
The study, which was cosponsored by National Eye Institute (NEI) and National Center for Complementary and Alternative Medicine (NCCAM), included 34 adults with retinitis pigmentosa. They were randomly assigned to one of two groups. The first group received lutein supplements (10 mg per day) for 12 weeks, followed by 30 mg per day for an additional 12 weeks. They then received a placebo for 24 weeks. The second group received the placebo for 24 weeks before receiving lutein.
Lutein significantly improved the visual field, and this effect increased over time. There was also an improvement in visual sharpness (acuity) among those taking lutein, but the results did not reach statistical significance. Comparing the results against the natural loss expected to occur over 48 weeks, most measures showed that lutein reduced the rate of visual decline. Many of the improvements that resulted from lutein supplementation were not statistically significant, probably because of the small number of people in the study.
Lutein is an antioxidant in the carotenoid family. Good sources include spinach, kale, collard greens, romaine lettuce, leeks, peas, and egg yolks. It is the primary carotenoid found in the retina and has been shown in previous studies to slow macular degeneration, the leading cause of blindness in older adults.
“Our findings suggest that lutein supplementation improved the visual field and also might slightly improve visual acuity in people with retinitis pigmentosa,” said Dr. Dagnelie. “The results should be viewed cautiously, and more research is needed, but for people facing the possibility of losing their vision, lutein is a safe treatment that is certainly worth trying.”
(BMC Ophthalmology 2006, 6:23 [doi:10.1186/1471-2415-6-23])
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Jeremy Appleton, ND, CNS, is a licensed naturopathic physician, certified nutrition specialist, and published author. Dr. Appleton was the Nutrition Department Chair at the National College of Naturopathic Medicine, has served on the faculty at Bastyr University of Natural Health Sciences, and is a former Healthnotes Senior Science Editor and a founding contributor to Healthnotes Newswire. He has worked extensively in scientific and regulatory affairs in the supplement industry and is now a consultant through his company Praxis Natural Products Consulting and Wellness Services.
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