Macular degeneration is the leading cause of blindness in the US in those over 65. Twenty-five to thirty million people are afflicted worldwide and currently there are no effective treatments for the disease. The disease has two forms known as dry and wet AMD.
Ninety percent of the AMD cases diagnosed are the dry form. In dry AMD, also referred to as early AMD, debris deposits under the center of the retina (known as the macula) interfering with its normal function. Parts of the macula atrophy, causing the central vision to slowly become dimmer or more blurry. Wet age-related macular degeneration, also known as late AMD, often develops in areas where dry AMD exist. Abnormal blood vessels grow and leak blood and fluid under the macula, causing scarring, which leads to a rapid loss of central vision.
Dr. Joanna Seddon published one of the first studies demonstrating a link between lutein intake and AMD risk in 1994 (1). This epidemiological study compared the risk of developing AMD to nutrient intake and showed a significant reduction in risk for developing AMD as lutein intake reached 6 mg per day (57% reduction in risk). Since the Seddon study, researchers have shown that increasing dietary lutien intake raises blood levels of lutein as well as levels of lutein in the eye (2). Bone et al. demonstrated that eyes with higher levels of lutein were less likely to be afflicted with AMD (3).
The latest clinical trial that investigated lutein's role in AMD is known as the Lutein Antioxidant Supplementation Trial (L.A.S.T.) (4). This study evaluated the effect of lutein supplementation for one year in 90 veterans diagnosed with dry AMD. Supplementation with lutein in these subjects significantly increased the concentration of lutein in the macula. Improvements in visual function were also detected with lutein supplementation. Glare recovery, visual acuity, and contrast sensitivity were all improved. This study continues to build on clinical evidence that the dry for of AMD may be responsive to changes in nutrition.
