NUTR 225 Ch. 8

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NUTR 225 Ch. 8
2013-06-09 18:48:43
Nutrition NUTR 224

Nutrition 225 Final
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  1. Antioxidants
    Chemicals that protect cells from damage from oxidation, including the following: Vitamin E, C, A, Beta-carotene, Selenium
  2. Atom
    • Smallest unit of matter.
    • Consists of:
    • - Nucleus: positively charged portion of the atom
    • - Electrons: negatively charged particles surrounding the nucleus
  3. Oxidation and Reduction
    O: The loss of electrons from a molecule

    R: The gain of electrons by a molecule

    Usually occur together as an exchange reaction
  4. Free radical
    • An atom that has lost an electron and is left with an unpaired electron
    • - highly reactive, can cause damage to molecules in the cell
  5. Free radicals are produced by...
    • Pollution
    • UV light and radiation
    • Toxic substances
  6. Impact of free radicals
    • Can cause damage to:
    • - Cell membranes
    • - LDLs
    • - Proteins in the cell
    • - DNA
  7. Diseases linked to free radicals
    Cancer, Heart Disease, Diabetes, Arthritis, Cataracts, Kidney Disease, Alzheimer's, Parkinson's
  8. Vitamin E
    Fat-soluble made with tocotrienol (biologically inactive form) and tocopherol (biologically active form)
  9. Functions of Vitamin E
    • - Antioxidant
    • - Protects polyunsaturated fatty acids
    • - Protects LDLs
  10. Recommended amount of Vitamin E
    • - 15gm alpha-tocopherol/day
    • - 1000mg/day for UL
  11. Too much Vitamin E vs. Not enough Vitamin E
    Too much: possible link to vascular disease, diabetes, heart failure; nausea and diarrhea

    Too little: uncommon, can result in fragile red blood cells (erythrocyte hemolysis)
  12. Vitamin C
    Water-soluble vitamin that must be consumed in the diet
  13. Functions of Vitamin C
    • -Antioxidant
    • - Synthesis of collagen
    • - Prevents scurvy
    • - Enhances immune system
    • - Enhances absorption of iron
  14. Recommended amount of Vitamin C
    • 90mg/day for men
    • 75mg/day for women

    smokers need an extra 35mg/day
  15. Too much Vitamin C vs. Not enough Vitamin C
    Too much: 10x more can cause nausea, diarrhea, nosebleeds, abdominal cramps

    Too little: Scurvy, bleeding gums, loose teeth, weakness
  16. Beta-carotene
    • - A weak antioxidant
    • - Also is a provitamin: inactive precursors that must be converted to the active form of a vitamin in the body
  17. Too much beta-carotene vs. Not enough beta-carotene
    Too much: Skin may turn yellow or orange, which is harmless and reversible

    Too little: No known deficiency symptoms
  18. Vitamin A
    • Fat-soluble vitamin.
    • -Retinol
    • -Retinal
    • -Retinoic acid
  19. Functions of Vitamin A
    • - Proper vision
    • - Antioxidant, protecting LDL cholesterol
    • - Cell differentiation
    • - Sperm production and fertilization
    • - Bone growth
  20. Recommended intake for Vitamin A
    • 900𝜇g/day for men
    • 700𝜇g/day for women
  21. Too much Vitamin A vs. Not enough Vitamin A
    Too much: extremely toxic, birth defects and permanent damage to liver and eyes

    Too little: Night blindness, irreversible blindness (xerophthalimia)
  22. Selenium
    trace mineral found in a few amino acids in the body
  23. Functions of Selenium
    • - Antioxidant
    • - Production of thyroxine, a thyroid hormone
  24. Recommended intake of Selenium
    55𝜇g/day for men and women
  25. Too much selenium vs. Not enough selenium
    Too much: selenium toxicity (brittle hair, nails, skin rashes

    Too little: Keshan disease- a form of heart disease; Kashin-Beck disease- a type of arthritis
  26. Cofactor
    compound needed for proper functioning of an enzyme

    (e.g.: copper, zinc, manganese are cofactors for the superoxide dismutase enzyme antioxidant system)
  27. Cancer, Three steps?
    A group of related diseases characterized by cells growing out of control

    • 1) Initiation- cell's DNA is mutated
    • 2) Promotion- altered cell repeatedly divides
    • 3) Progression- cells grow out of control
  28. Factors that increase cancer risk
    • - Tobacco use
    • - Weight, diet, physical activity level
    • - Infectious agents (STDs)
    • - Sun exposure
    • - Environmental/occupational exposure
  29. Signs and symptoms of cancer
    - Unexplained weight loss, fever, extreme fatigue, pain, skin changes, changes in bowel movement, indigestion, unusual bleeding/discharge, skin thickens or lumps, nagging cough or hoarseness
  30. Cancer Treaments
    • -Surgery
    • -Radiation
    • -Chemotherapy
  31. Cancer Prevention
    • Check: get screenings and exams
    • Quit: stop smoking and alcohol abuse
    • Move: get regular physical activity
    • Nourish: maintain a recommended weight and eat a balanced, healthful diet
  32. Role of Antioxidants in Cancer
    • -Enhance immune system
    • -Inhibit growth of cancer cells
    • -Prevent oxidation damage to cells