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Antioxidants

Antioxidants. Oxidation. Chemical rx in which atoms lose electrons May result in free radical formation. Structure of Atoms. Atom : the smallest unit of matter. Atoms are composed of Nucleus – positively charged center portion of the atom

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Antioxidants

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  1. Antioxidants

  2. Oxidation • Chemical rx in which atoms lose electrons • May result in free radical formation

  3. Structure of Atoms • Atom: the smallest unit of matter. • Atoms are composed of • Nucleus – positively charged center portion of the atom • Electrons – negatively charged particles surrounding the nucleus

  4. Oxidation • Molecules are composed of atoms. • During metabolic reactions, electrons can be transferred • From the atoms of one molecule • To the atoms of another molecule

  5. Oxidation

  6. Oxidation • Oxidation: the loss of electrons from a molecule. • Reduction: the gain of electrons by a molecule. • Oxidation and reduction usually occur together as an exchange reaction.

  7. Oxidation • Stable atoms contain an even number of paired electrons. • Free radical:an atom that has lost an electron and is left with an unpaired electron. • Free radicals are highly reactive and can cause damage to molecules in the cell.

  8. Free Radicals and Diseases

  9. Antioxidants • Substances that are able to neutralize reactive molecules and reduce oxidative damage • Result of metabolic processes and environmental sources • Vitamin C, Vitamin E, beta-carotene, Vitamin A, selenium, iron, zinc, copper and manganese

  10. Vitamin E • Functions: Anti-oxidant • Guards against damage to membranes from oxidizing compounds • Deficiency: Rare (premature infants under 3.5 pounds, people unable to absorb fat or metabolize fat properly • Suppresses the immune system because vitamin E protects White Blood Cells

  11. Vitamin E • Toxicity: Rare • Sources: Vegetable oils, nuts and green leafy vegetables, fortified cereals

  12. There's sweet news about hot cocoa • Hot cocoa tops red wine and tea in antioxidants; may be healthier choice • More antioxidants per cup than a similar serving of red wine or tea • per serving basis, the antioxidant concentration in cocoa was the highest: It was almost 2 times stronger than red wine, 2-3 times stronger than green tea, and 4-5 times stronger than that of black tea • New research underlines antioxidant activity in chocolate • Vitamin E tocotrienol shows brain protection promise

  13. Vitamin C Functions • Collagen Formation • antioxidant • reduce cancer risk • helps absorb iron from food • Reduces risk of colds????? • probably not • Linus Pauling’s study • NutraIngredients

  14. Vitamin C • Deficiency: called scurvy • poor formation of collagen in blood vessels • weak vessels result in hemorrhages • can be severe and result in lots of blood loss and death • Toxicity: may result in • kidney stones • rebound scurvy • Destruction of B12 • Problems with acid/base balance

  15. Vitamin C: RDA 90/75 mg/day • Foods rich in vitamin C: • 1 cup fresh squeezed orange juice: 124 mg • 1 cup canned o.j.: 84 mg • Smoker’s RDA = +35 mg/day • Some of vitamin C is sacrificed in reducing the oxidants of cigarette smoke • Vitamin C intake offers protection against stomach cancer

  16. Beta-Carotene-provitamin • Functions • Weak antioxidant • Enhance immune system • Protect skin and eyes • Deficiency/toxicity

  17. Beta-Carotene-provitamin • No RDA • Sources

  18. Vitamin A Functions • Vision: helps with conversion of light energy to electrical energy in eye • Cell differentiation-maintenance of linings: • helps produce the CHO normally found in mucous • Bone growth: • helps with remodeling growing bones

  19. Vitamin A Deficiency • One year supply in fat and liver of most people: So deficiencies are rare • Bone growth and remodeling problems • shape changes • Linings deteriorate • GI tract: diarrhea • Respiratory tract: infections • urogenital tract: infections, kidney stones • Impaired night vision and day vision

  20. Vitamin A Toxicities • Bones: • decalcification, joint pain • Nervous system • loss of appetite, irritability, muscle weakness • Liver enlargement • jaundice • Blood: RBCs loose hemoglobin • Bleeding induced easily

  21. Beta carotene and Vitamin A

  22. Vitamin A RDA= 700 RE for females; 900 RE for males. • RE= Retinol Equivalent • Retinol is the active form of vitamin A • Other molecules can be metabolized to make Retinol, thus retinol equivalents • e.g.: beta carotene can be modified to make retinol • beta carotene is found in carrots and other deep orange and green vegetables • 1 RE= 1 microgram of retinol • 1 RE= 3.3 IU retinol • 1 RE = 12 micrograms of beta carotene

  23. Selenium • Functions • Antioxidant system • Thyroxine and immune function • Deficiency • Keshan disease • Impaired immune response, cognitive function, muscle pain, wasting • The Link between Selenium and Chemoprevention: A Case for Selenoproteins -- Diwadkar-Navsariwala and Diamond 134 (11): 2899 -- Journal of Nutrition

  24. Selenium – RDA 55 mg/day • Sources • Nuts • Seafood • Pasta

  25. Disorders related to Oxidation • Cancer - Definitions • Cancer: uncontrolled growth and spread of abnormal cells • Tumor: mass of cancer cells • benign tumor (non-harmful, non-invasive) • malignant tumor (harmful, invasive) • Metastatic Cancer: spreading

  26. Cancer Facts • US men have a 1 in 2 lifetime risk • US women have a 1 in 3 lifetime risk • 1,220,000 new malignant cancer cases in 2000 • 552,000 cancer deaths in 2000 • Cancer the Top Killer for Those Under 85 – Jan 20, 2005

  27. Cancer TrendsJNCI, 1999 • 1990-1996 • All cancer incidence declined by 2.2% • -4.1% males • -0.5% females • USATODAY.com - Cancer deaths lowest in 7 decades

  28. US Mortality, 2000 No. of deaths % of all deaths Rank Cause of Death • 1. Heart Diseases 710,760 29.6 • 2. Cancer 553,091 23.0 • 3. Cerebrovascular diseases 167,661 7.0 • 4. Chronic lower respiratory diseases 122,009 5.1 • 5. Accidents (Unintentional injuries) 97,900 4.1 • 6. Diabetes mellitus 69,301 2.9 • 7. Influenza and Pneumonia 65,313 2.7 • 8. Alzheimer’s disease 49,558 2.1 • Nephritis 37,251 1.5 • 10. Septicemia 31,224 1.3 Source: US Mortality Public Use Data Tape 2000, National Center for Health Statistics, Centers for Disease Control and Prevention, 2002.

  29. 2004 Estimated US Cancer Deaths* Men285,900 Women270,600 Lung & bronchus 32% Prostate 10% Colon & rectum 10% Pancreas 5% Leukemia 5% Non-Hodgkin 4%lymphoma Esophagus 4% Liver/intrahepatic 3%bile duct Urinary bladder 3% Kidney 3% • 25% Lung & bronchus • 15% Breast • 10% Colon & rectum • 6% Pancreas • 6% Ovary • 4% Leukemia • 3% Non-Hodgkin lymphoma • 3% Uterine corpus • 2% Brain/ONS • 2% Multiple myeloma ONS=Other nervous system. *Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder. Source: American Cancer Society, 2003.

  30. The Cancer Development Process • Initiation • Alterations in DNA • minutes - days • Causes: • radiation • chemical carcinogens • viruses

  31. The Cancer Development Process • Promotion • “locking” DNA alterations • failure of DNA repair mechanisms • months - years

  32. The Cancer Development Process • Cancer Progression • Uncontrolled growth of cancer cells • malignancy and metastasis • weeks to years

  33. Cancer Development http://science.education.nih.gov/supplements/nih1/cancer/activities/activity2_animations.htm

  34. Diet and Cancer Development • Initiation • Dietary sources of carcinogens • aflatoxin mold from peanuts • benzopyrene from charbroiled meats • nitrosamine from cured meats • AICR Press Corner - Recent News • Protection • phytochemicals • antioxidants • dietary fiber • Study will assess effect of tomato oil on precancerous prostate changes

  35. Diet and Cancer Development • Promotion • Fat and PUFA • excess alcohol • Progression • excess Fat and calories • Alaska Journal of Commerce Online

  36. Diet and CancerACS 2000 • One third of cancer deaths in US is due to cigarette smoking • One third of cancer deaths in US is due to diet • 5-10% of cancers are hereditary • NutraIngredients

  37. 1999 ACS Dietary Guidelines • Choose most of the foods you eat from plant sources. • Five A DayHealthy fruit and veg compounds being lost in processing • low in fat and calories • high in folic acid, vitamin C, beta-carotene • high in fiber • high in phytochemicals • ABC News: Turn to Tomatoes for Prostate Health • FOXNews.com - Health - Vitamin D May Lower Some Cancer Risk

  38. Trends in Consumption of Recommended Vegetable and Fruit Servings (5 or more) for Cancer Prevention, Adults 18 and Older, US, 1994-2000 Prevalence (%) 2000 1996 1998 1994* * Includes fewer than 50 states and the District of Columbia. All other prevalences include the 50 states and District of Columbia. Source: Behavioral Risk Factor Surveillance System, 1994, 1996, 1998, 2000, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, 1997, 1999, 2000, 2001.

  39. Cardiovascular Disease (CVD) • Risk factors • Smoking • Hypertension • High LDL • Obesity • Sedentary life style • Nutrition Notes: How to fight inflammation - Nutrition Notes - MSNBC.com

  40. CVD and Antioxidants • Scavengers • Donates electrons • Reduction of inflammation • Enhances immune system • Reduction of blood coagulation

  41. Vision impairment • Macular degeneration • Promising results • Cataracts • Mixed results

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