1a. Objectives (from AD-416):
LAB: ANTIOXIDANTS Objective 1. Identify and quantify the phytochemical content of: blueberries, cranberries, and grapes; almonds, pistachios, and walnuts; whole grains; and cocoa-based foods; and contribute to future updates of the USDA Database for the Flavonoid Content of Selected Foods. Objective 2. Determine the bioavailability, pharmacokinetics, metabolism and bioactivity of flavonoids and other phytochemicals from antioxidant-rich foods using in vitro experiments, animal models, and human studies.. Objective 3 Investigate the effect of age on quercetin bioavailability and metabolism due to changes in phase II enzyme activity. Objective 4. Test whether exposure of rat dams to a “Western” diet during pregnancy and lactation will increase obese phenotypes in their pups and whether dietary flavonoids, particularly isoflavones, will decrease the obese phenotype. LAB: CAROTENOIDS Objective 1: Determine the ability of bioactive plant-based foods, including carotenoid-rich foods to exert biological functions and affect genomic stability. Objective 2: Determine the vitamin A requirement of healthy U.S. adults.
1b. Approach (from AD-416):
LAB: ANTIOXIDANTS Using advanced chromatographic methods, we will measure the flavonoid content and evaluate the total antioxidant capacity of selected plant foods and the influence of geographical regions, agricultural practices, and processing and storage. A rat model as well as microsomes from various rat tissues will be utilized to determine the effect of age on quercetin bioavailability and metabolism due to changes in phase II enzyme activity. We will explore the possible fetal origins of chronic disease by feeding obesigenic diets to rat dams during pregnancy and lactation and examine the change in obese phenotypes in their pups and test whether dietary flavonoids, particularly isoflavones, will decrease this phenotype. Using healthy older adults, we will determine the bioavailability and distribution of cranberry anthocyanins to blood, urine, and feces. Employing volunteers with coronary heart disease, we will test the effect of almond consumption on biomarkers of oxidative stress, inflammation, and vascular reactivity. LAB: CAROTENOIDS 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 non-denaturing 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 aphereses-autologues 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:
This progress report includes the work of two subordinate projects at the HNRCA funded through a Specific Cooperative Agreeement with TUFTS UNIVERSITY. For further information and progress reports, see 1950-51000-073-01S(Antioxidants Research) and 1950-51000-073-02S (Carotenoids and Health).
1. LAB: Antioxidants Research: Cranberry A-type proanthocyanidins (PAC-A) are found in uniquely high concentrations in cranberries. In test tube studies, these PAC-A prevent the bacteria causing urinary tract infections from adhering to the bladder wall. However, data on PAC-A absorption in humans has not been established due to the lack of a method for their quantification. We conducted an acute study in healthy older adults of the absorption and distribution of cranberry phytochemicals from a cranberry juice cocktail. Using a novel separation and analytical method with mass spectrometry, we detected the presence of cranberry PAC-A in urine with a peak concentration occurring 11 hours after acute consumption of cranberry juice. This study represents the first demonstration of the absorption of cranberry PAC-A into plasma and its distribution to the bladder, a necessary step to understanding the mechanisms of action underlying the benefit of cranberry products on urinary tract infections. These data also suggest that PAC-A may be a useful biomarker of cranberry intake.
2. LAB: Carotenoids and health: Relationship established between retinal and brain lutein. ARS-funded scientists at the JMUSDA-HNRCA at Tufts University in Boston, MA found that lutein levels in the macula of the retina reflect lutein levels in the primate brain. Macular pigment (lutein in the macula) can be measured non-invasively in humans. Thus, macular pigment density is a biomarker of brain lutein. Our work showed that in brain lutein levels are significantly related to pre-mortem measures of cognition and that macular pigment is a biomarker of brain lutein. Macular pigment assessment may be an important tool to confirm the effect of a dietary intervention containing lutein on cognitive function in the elderly. Nutritional Interventions are cost effective, rational approaches to combat age-related cognitive decline. This is important because age-related cognitive decline is expected to rise due to the increase in the aging population.
3. LAB: Carotenoids and health: Biofortified rice and maize are good sources of vitamin A to combat global vitamin A deficiency. Through evaluation of biofortified plant foods, especially staple crops biofortified with provitamin A beta-carotene, ARS-funded researchers at JMUSDA-HNRCA at Tufts University, Boston, MA, found that the staple plant foods beta-carotene fortified Golden Rice and yellow maize, are good sources in providing vitamin A. In consideration of world-wide vitamin A deficiency, biofortification of staple crops that are enriched with beta-carotene might be a long term and sustainable solution to combat vitamin A deficiency globally.
Bolling, B., Chen, C., Mckay, D., Blumberg, J. 2011. Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts. Nutrition Research Reviews. 24:244-275.