ABSTRACT
Zeaxanthin, a hydroxylated carotenoid, is an important plant food
xanthophyll. Together with lutein, they are found in the macula pigment of the central retina of the eye responsible for the yellow coloration (Snodderly et al., 1986). Since the source of the macular pigment is solely dietary-based, studies have examined the possible relationship between the pigment and dietary intake. The majority of dietary zeaxanthin and lutein (78 percent) are obtained from such vegetables as spinach and orange pepper, although they are also found in egg yolk (Summerburg et al., 1998; USDA, 1998). The importance of the macula pigment is its protection against agerelated maculopathy, one of the major causes of blindness in Western countries (Klaver et al., 1998). Modified diets that are supplemented with zeaxanthin and lutein were shown to augment or enhance the macular pigment optical density (Hammond et al., 1997; Johnson et al., 2000). Both zeaxanthin and lutein are strong antioxidants, as age-related maculopathy is due to a combination of cumulative blue-light damage or oxidative stress (Beatty et al., 2000). Thus, oxidative stress appears to play a role in such neurodegenerative diseases as age-related macular degeneration (ARMD), the primary cause of blindness in seniors in developed countries (Leibowitz et al., 1980; Klein et al., 1992).
