Robert Parker
Associate Professor
2009
HENutrSci

Web Bio Page

Current Activities

Current Professional Activities

Cornell University Graduate Field Membership: Nutrition; Food Science and Technology

Teaching in the areas of nutrition and food quality and nutritional biochemistry. Research in the areas of metabolism and bioavailability of fat soluble nutrients, particularly vitamin E and vitamin K



Current Research Activities
Biochemical and physiological factors influencing metabolism, transport and bioavailability of vitamin E and vitamin K.  Focus on cytochrome P450-mediated vitamin E metabolism and on mechanisms of cellular secretion of vitamin E that influence vitamin E status, including response to supplementation and impact of genotype.  Additional focus on novel pathways of metabolism of vitamin K, particularly those responsive to the anticoagulant warfarin.

Biography

Biographical Statement

My research program focuses primarily on mechanisms of regulation of vitamin E and vitamin K status.We are addressing important gaps in the metabolic processing of the various forms of vitamins E and K in humans, including basic metabolic phenomena and applied aspects of their bioavailability. We recently (2002) identified and published the first enzyme-mediated pathway of vitamin E metabolism, and much of our current work centers on understanding how this pathway is regulated, the forms of vitamin E for which it is most relevant, and means by which the pathway can be manipulated to alter vitamin E status. Other efforts are aimed at elucidating how vitamin E is secreted from cells, with particular relevance to intestine and liver (bile).  We apply a combination of cell culture, animal studies (genetically modified mice), and human metabolic studies to this research. The outcome of this research has impacted, and will continue to impact, the dietary recommendations for these nutrients (and foods containing them), in addition to providing insight as to their role in human health. My teaching program centers on nutritional and physicochemical aspects of foods, providing undergraduate and graduate students with a broad-based background in chemical and physical characteristics/phenomena which impact food quality, and on various subjects of current interest, including food safety and biotechnology.  In addition, I teach in graduate courses in nutritional biochemistry, addressing subjects of fat soluble vitamins, lipoproteins, and lipid status. I carry a joint appointment in the Department of Food Science.



Education
  • Ph.D. 1980 - Oregon State University, Food Science
  • M.S. 1978 - Oregon State University, Food Science
  • B.S. 1974 - Duke University, Zoology and Botany


    • Administrative Responsibilities
    Chair, DNS Curriculum Committee
    DNS representative to CALS Curriculum Committee
    Chair, Admissions Committee, DNS Post-Baccalaureate Program in Health Sciences

    Keywords


    Courses, Websites, Pubs

    Courses Taught

    NS 3450 Nutritional and Physicochemical Aspects of Foods

    NS 6310 Micronutrients: Function, Homeostasis and Assessment

    NS 6320 Regulation of macronutrient metabolism



    Related Websites
    DNS Home Page

    Selected Publications
    Ohnmacht S, Nava P, West R, Parker R, Atkinson J. (2008)  Inhibition of oxidative metabolism of tocopherols with omega-N-heterocyclic derivatives of vitamin E. 2008. Bioorganic & Medicinal Chemistry 16(16), 7631-7638.

    Sontag, TJ and Parker, RS. (2007) Influence of major structural features of tocopherols and tocotrienols on their omega-oxidation by tocopherol-omega-hydroxylase. J Lipid Res. 48(5), 1090-1098.

    Frank J, Budek A, Lundh T, Parker RS, Swanson JE, Lourenco CF, Gago B, Jaranjinha J, Vessby B and Kamal-Eldin A. (2006) Dietary flavonoids with a catechol structure increase alpha-tocopherol in rats and protect the vitamin from oxidation in vitro. J. Lipid Res 47(12), 2718-2725.

    You C-S, Sontag TJ, Swanson JE, Parker RS. (2005) Long-chain carboxychromanols are the major metabolites of tocopherols and tocotrienols in A549 lung epithelial cells but not HepG2 cell. J Nutr 135:227-232.

    Parker RS and McCormick CC. (2005)  Selective accumulation of alpha-tocopherol in Drosophila melanogaster is associated with tocopherol-omega-hydroxylase activity but not with tocopherol transfer protein. Biochem. Biophys. Res. Comm. 338:1537-1541.

    Ross AB, Chen Y, Frank J, Swanson JE, Parker RS, Kozubek A, Lundh T, Vessby B, Aman P, Kamal-Eldin A. (2004) Cereal alkylresorcinols elevate gamma-tocopherol levels in male Sprague-Dawley rats and inhibit gamma-tocopherol metabolism in vitro. J Nutr 134:506-510.

    Soo CC-Y, Haqqani AS, Hidiraglou N, Swanson JE, Parker RS, Birnboim HC. (2004) Dose-dependent effect of dietary alpha and gamma tocopherol on genetic instability in mutatect mouse tumors. J Natl Cancer Inst 96(10):796-800.

    McCormick CC, Parker RS. (2004) Cytotoxicity of vitamin E is both vitamer- and cell-specific and involves a selectable trait. J Nutr 134(12):3335-42.

    Parker RS, Sontag TJ, Swanson JE, McCormick CC. (2004) Discovery, characterization and significance of the cytochrome P450 omega-hydroxylase pathway of vitamin E catabolism. In: Vitamin E and Health, Vol. 1031:13-21, F. Kelly, M. Meydani, and L. Packer, eds. Annals Online, www.annalsnyas.org

    Frank J, Lundh T, Parker RS, Swanson JE, Vessby B, Kamal-Eldin A. (2003) Dietary (+)-catechin and BHT markedly increase alpha-tocopherol concentrations in rats by a tocopherol-omega-hydroxylase-independent mechanism. J Nutr 133 (10):3195-3199.

    Edwards AJ, Nguyen CH, You C-S, Swanson JE, Emenhiser C, Parker RS. (2002) Alpha- and beta-carotene from a commercial carrot puree are more bioavailable to humans than from boiled-mashed carrots, as determined using an extrinsic stable isotope reference method. J Nutr 132:159-167.

    Sontag TJ, Parker RS. (2002) Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status. J Biol Chem 277(28):25290-25296.