Start Date: May 01, 2009
End Date: Apr 30, 2014
By recruiting older adults (>60 yr, men and post-menopausal women) without and with metabolic syndrome to ingest bioactive plant foods or histidine dipeptide rich foods, we will measure plasma total antioxidant performance, plasma in vivo oxidative stress biomarkers, plasma water-soluble and fat-soluble antioxidants (carotenoids, tocopherol, ascorbic acid, and uric acid), plasma biomedical parameters to determine the ability of bioactive plant-based foods, including carotenoid-rich foods, to exert biological functions and affect genomic stability. Also, to explore a possible correlation between a change in serum apoE and a change in Macular Pigment (MP) density, we will measure HDL subpopulations by nondenaturing 2d gel electrophoresis, immuno-blotting, and image analysis. We will measure lipoproteins, antioxidative capacity, and markers of inflammation in order to better define the mechanism by which decreased body weight is associated with increased MP in humans. Using the stable isotope labeled vitamin A (labeled in three different levels, ^13 C_4 , ^13 C_8 , ^13 C_12 – retinyl acetate) and apheresesautologues technique on human volunteers, we will measure the enrichment of these labeled retinols in human circulations and mathematical modeling to determine vitamin A bioavailability and the requirement of vitamin A through an intervention trial with various levels of vitamin A.