Abstract
Abstract: :
Purpose:To examine and analyze responses of serum and urine markers from 55 elderly subjects in a 5 week study to two ocular antioxidant supplements, dietary intervention and placebo. Methods:Both supplements contained lutein and zeaxanthin (4 or 6 mg) and other antioxidant nutrients, and the dietary group consumed enough fruits and vegetables from each of four nutrient groups to provide an average of 6 mg lutein and zeaxanthin. Serum and urine samples were analyzed at the beginning and end of the study. Serum analyses included antioxidant concentrations (lutein, zeaxanthin, several other carotenoids, Vit. E) and measures of oxidative stress (ORAC and LPO). Urine analysis included MDA and other alkenals, and 8-OHdG. Results:The results suggest that lutein, zeaxanthin, and Vitamin E derived from these supplements or from augmented diet may result in significant increases in serum levels over periods as short as 5 weeks, with no significant differences between study supplements and diet. Initial analyses of some markers of oxidative stress indicated little impact of the intervention; however, detailed analysis of the results and more recent evaluations indicate the importance of both segmenting the population in terms of oxidative stress and antioxidant status, and distinguishing amongst types of oxidative stress. For example, ORAC values can be shown to correlate with water-soluble antioxidants, specifically Vitamin C, but are little influenced by carotenoids. Recent work suggests carotenoids also can influence the serum antioxidant status. Conclusion:Within 5 weeks, the dietary supplements in this study provided augmentation of serum carotenoids and Vitamin E by as much as 100%, amounts comparable to those observed from augmentation by a diet supplemented daily with four vegetable groups. The data suggest that these supplements or a diet rigorously enriched with carotenoid antioxidants may offer potential for enhancing levels of macular pigments. The data also indicate the subtlety of identifying the effects of these increased levels of antioxidants on markers of oxidative stress in an aged but non-stressed population.
Keywords: 337 carotenoids/carotenoid binding proteins • 321 antioxidants • 308 age-related macular degeneration