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Lutein Other Names: Xanthophyll Uses In general, individuals who consume large quantities of the vegetables and fruits that contain lutein may be less likely to develop cataracts and age-related macular degeneration (AMD) than individuals with a lutein-poor diet. AMD results from the deterioration of the retina's central section. Partial or total vision loss may occur. Lutein is one of the two most common pigments (coloring agents) in the retina. It is believed to block out blue light and to protect retinal tissue from being damaged by light. In older individuals, the layer of yellow pigment in the retina tends to become thinner, increasing the chance for AMD. Taking lutein may thicken the yellow layer. In addition, lutein acts as an antioxidant to protect the interior of the eyes from damage by oxygen free radicals, natural chemicals produced in the body. Although a recent very large observational study of humans failed to prove that lutein affected the development of glaucoma, some earlier evidence suggests that lutein may help prevent some types of glaucoma, as well. Further studies are being conducted to better understand lutein's possible role in glaucoma. Consumption of vegetables and fruits has long been associated with reduced rates of heart disease and some cancers. Because lutein is a major component of some plant foods known to be among the most protective, its antioxidant effects are thought to play a major part in preventing these conditions. In animal and human studies, lutein has been investigated for possible effects against atherosclerosis (hardening of the arteries). However, results from several human studies conflict with each other. While some seem to show that high lutein levels correlate with lower risk of atherosclerosis, other studies find little or no anti-atherosclerotic effect from lutein. While generally positive, results from studies of lutein in cancer are mixed, too. For cancer prevention, lutein is believed to increase the death rate of cancer cells. At the same time, it may decrease the growth of blood vessels that supply cancerous tumors. In laboratory studies, lutein has also appeared to change the ways that DNA repairs itself. Lutein has shown some effectiveness in studies of breast, colon, lung, and ovarian cancers in humans. Additionally, in laboratory mice, oral doses of lutein reduced the extent of skin damage from exposure to ultraviolet light. A possible protective effect from skin cancer may result. However, in an observational study of over 1,000 individuals in China, high blood levels of lutein seemed to be related to a slightly increased risk of having stomach cancer. The use of lutein in both heart disease and cancer needs more study. |