1a. Objectives (from AD-416)
1. Determine the ability of bioactive plant-based foods, including carotenoid-rich foods to exert biological functions and affect genomic stability. 2. Determine the vitamin A requirement of healthy U.S. adults.
1b. Approach (from AD-416)
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.
3. Progress Report
Recently, ARS-funded scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, MA have reported that bioactive plant foods, such as angel’s plant (Angelica keiskei) are rich in phytochemiclas including carotenoids (antioxidant) and a group of chalcones (purported to have antidiabetic and antihypercholesterolemic functions). We showed that human subjects who consumed angel’s plant dry powder (5 g per day) exhibit increases in antioxidant performance in both healthy and metabolic syndrome subjects. Further study will determine if long term feeding with angel’s plant will reduce the DNA damage in the metabolic syndrome group, which was significantly higher than the healthy group at the baseline.
1. Developed a Rapid Analysis Method Determining Phenolics in Plant Extract. ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, developed a rapid analysis method determining phenolics in plant extract (Angelica keiskei and Glycine max) using a high resolution mass spectrometry coupled with informatics. This newly developed instrumentation method can further evaluate the phytonutrients in plant foods and benefit for agriculture plant choices. This accomplishment is significant because it provides a powerful and rapid new method to analyze bioactive components in plant foods.
2. Lutein and Zeaxanthin Intake are related to Eye Health. ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, found accurate assessment of intake of lutein and zeaxanthin that are selectively taken up into the macula of the eye may protect against the development of age-related macular degeneration. This is important in understanding of their individual roles in eye health. We analyzed the top major food sources for lutein and zeaxanthin intake in NHANES (National Health and Nutrition Examination Survey) 2003-2004 by high-performance liquid chromatography. The results were applied to dietary data from 8,525 participants in NHANES 2003-2004. Our findings suggest that the relative intake of lutein and zeaxanthin may be important to age-related macular degeneration risk and the individual intake of lutein or zeaxanthin may be associated with eye health. These data provide the basis for defining the adequate intake of lutein and zeaxanthan for optimal eye health.
3. High Beta Carotene Maize Effectively Converts to Vitamin A in Zimbabwean Men ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, reported that biofortified high beta carotene maize and its conversion to vitamin A were studied in Zimbabwean men. The volunteers consumed intrinsically labeled high betacarotene yellow maize. The results showed a very effective conversion of maize beta carotene to vitamin A (3.2 unit of beta carotene provided 1 unit of vitamin A by weight). The results provided a strong evidence that high beta carotene yellow maize is very effective dietary source for vitamin A and thus to help combat vitamin A deficiency in maize eating populations around the world.