Vitamin C at work in the eye.Vitamin C vitamin Cor ascorbic acid Water-soluble organic compound important in animal metabolism. Most animals produce it in their bodies, but humans, other primates, and guinea pigs need it in the diet to prevent scurvy. at work in the eye Vitamin C delays molecular changes in the eye that lead to cataracts Cataracts Definition A cataract is a cloudiness or opacity in the normally transparent crystalline lens of the eye. This cloudiness can cause a decrease in vision and may lead to eventual blindness. by slowing the wearing effects of light and oxygen, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. researchers at Tufts University's Laboratory for Nutrition and Cataract Research in Boston. Cataracts are caused by the long-term action of light and oxygen on crystallins, the proteins in the eye's lens that transmit light, explains lab director Allen Taylor. This oxidation causes the proteins to precipitate out and clump together as cloudy cataracts. The lens contains enzymes that counteract the process, but they also begin to oxidize oxidize /ox·i·dize/ (ok´si-diz) to cause to combine with oxygen or to remove hydrogen. ox·i·dize v. 1. To combine with oxygen; change into an oxide. 2. as the eye ages. Because vitamin C, or ascorbic acid, is naturally plentiful in the eye--as much as 30 times more plentiful than in the blood--Taylor and his colleagues thought it might be there to work against cataracts. To find out, he treated cultured lens tissue with ultraviolet light Ultraviolet light A portion of the light spectrum not visible to the eye. Two bands of the UV spectrum, UVA and UVB, are used to treat psoriasis and other skin diseases. to cause oxidation. He found that the more ascorbic acid present, the longer it took cataracts to form. Experiments on guinea pigs further showed that large amounts of vitamin C in the diet lead to a buildup of ascorbic acid in the eye. Next, Taylor would like to figure out the optimum daily dose of vitamin C to combat cataracts in humans. |
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