Carotenoids for Better Vision
By Guy Chamberland
Cataracts are the leading cause of blindness in the world. According to epidemiologists, there are approximately 30-million blind people in the world, 50% are blind due to cataracts. The Eye Diseases Prevalence Research Group (EDPRG) estimated that in the year 2000 there were 20.5-million people over 40 years of age in the United States (17.2 percent) with a cataract in either eye and that there are more than 1-million extractions of cataracts per year.
A cataract is opacity of the lens of the eye that causes reduced visual acuity and can lead to blindness. The lens of the eye produces a structure composed of specialized cells that contain a very high content of cytoplasmic protein. It is this complex structure that gives the transparency to the lens. Unlike other tissues of our body, the lens doesn’t shed its nonviable cells and therefore it is susceptible to the degenerative effects of aging. Oxidation, or photo-induced oxidation, causes the degeneration of the lens which leads to the formation of the cataract.
Over the last 20 years evidence has been growing, showing the benefits of dietary carotenoids and eye health. A carotenoid is a class of mainly yellow, orange, or red fat-soluble pigments, including carotene, which give color to plant parts such as ripe tomatoes and autumn leaves. Previously, the frequent intake of fruits and vegetables was not consistently associated with the reduced risk of cataract. It was also discovered that not all the carotenoids were as effective in protecting the eye from the formation of a cataract. This explained why some clinical studies had not found an association between supplementing with food antioxidant intake and the decreased risk of cataracts.
Several clinical studies established that diets high in lutein and zeaxanthin had an inverse relation with the removal of cataracts. The CAREDS (Carotenoids in Age-Related Eye Disease Study) study showed that women in the highest quintile category of dietary lutein plus zeaxanthin as compared with those in the lowest quintile category were 32% less likely to have cataract. The high intake of spinach, which is rich in lutein, was consistently associated with a lower risk of cataract.
Lutein and zeaxanthin are the most abundant carotenoids in the lens and part of their role is to protect against the effects of oxidation. Research has also shown that lutein and zeaxanthin are the only carotenoids accumulated by the retina and other ocular tissues. Marigold petals (Tagetes Erecta L.), spinach, dark green lettuce, and broccoli are rich in these carotenoids.
Clinical research has established that a high intake of lutein and zeaxanthin helps to support eye health in conditions, such as cataracts. Supplements made from marigold petals are available for the reduction of the risk of cataracts. To obtain this potential health benefit, look for products that contain standardized extracts which are usually standardized to one of the following carotenoids: lutein, zeaxanthin, lutein esters or zeaxanthin esters.
Guy Chamberland is the Vice President of Research at CuraPhyteTechnologies. He can be contacted at email@example.com