PUBH 1517 - Basic Antioxidant Theory

PUBH 1517 - Basic Antioxidant Theory - Antioxidant Terms...

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Unformatted text preview: Antioxidant Terms Antioxidant: compound which neutralizes free radicals Free radical: atom or molecule with one or more unpaired electrons (unstable & highly reactive) Formed in process of using oxygen to produce energy. Oxidant: compound that oxidizes other compounds Oxidative stress: damage inflicted on living systems by free radicals The Theory of Antioxidants and Disease The Antioxidant Theory of Disease Prevention Body’s Defenses Against Free Radicals Against Dietary antioxidants: Vitamin C, Vitamin E, BetaCarotene, phytochemicals with antioxidant Carotene, activity activity Cellular enzymes that neutralize free radicals. Selenium-containing group Superoxide dismutase (SOD) Oral enzyme supplements are broken down by Oral digestion, and therefore ineffective as antioxidants antioxidants Evidence for the Antioxidant Theory of Disease Antioxidant People with highest cancer rates found to People have lowest fruit & vegetable consumption have Low blood concentrations of beta-carotene Low consistently correlated with development of cancers of the breast, cervix, & lung. of Several studies have found that people Several with diets rich in Vitamin C seem to develop fewer cancers of the mouth, larynx, & esophagus larynx, Evidence Against Use of BetaEvidence Carotene Supplements In a study of the effects of beta-carotene In supplements on lung cancer incidence, 28% more of those in the supplemented group developed lung cancer group 14 year study of physicians reported no 14 difference in disease rates between those who took beta-carotene supplements & those who took placebos those Vitamin E Evidence Vitamin Reduced risk of melanoma in people with Reduced high intakes of foods rich in Vitamin E high Vitamin E supplements generally found to Vitamin be useless against colon & lung cancers be Selenium Evidence Selenium In low selenium areas (in soil) of the U.S., In people suffer from higher rates of some cancers. people When 200 ug of selenium were given to 1300 When people with history of skin cancer over several years, years Incidence of recurrence about same in both control & Incidence experimental groups. Lower incidence of prostate, colon, & lung cancers in Lower experimental group. experimental All cause death rate same in both groups Summary of Evidence Summary While diets rich in antioxidants appear to While be effective in reducing cancer risk, antibe oxidant supplements are not always oxidant equally effective, and sometimes may actually be harmful. actually This could be due to effects of other This dietary components which are also high in diets high in antioxidants. diets ...
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This note was uploaded on 11/21/2011 for the course PUBH 1517 taught by Professor Paula.goldberg during the Winter '11 term at Life Chiropractic College West.

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