Transcript Antioxidants

Antioxidants
Oxidation
Chemical rx in which atoms
lose electrons
 May result in free radical
formation
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Structure of Atoms
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Atom: the smallest unit of matter.
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Atoms are composed of
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Nucleus – positively charged center portion
of the atom
Electrons – negatively charged particles
surrounding the nucleus
Oxidation
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Molecules are composed of atoms.
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During metabolic reactions, electrons can
be transferred
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From the atoms of one molecule
To the atoms of another molecule
Oxidation
Oxidation
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Oxidation: the loss of electrons from a
molecule.
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Reduction: the gain of electrons by a
molecule.
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Oxidation and reduction usually occur
together as an exchange reaction.
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.
Free Radicals and Diseases
Antioxidants
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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
Vitamin E
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Functions: Anti-oxidant
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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
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Suppresses the immune system because
vitamin E protects White Blood Cells
Vitamin E
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Toxicity: Rare
Sources: Vegetable oils, nuts and
green leafy vegetables, fortified
cereals
There's sweet news about hot
cocoa
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Hot cocoa tops red wine and tea in
antioxidants; may be healthier choice
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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
Vitamin C Functions
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Collagen Formation
antioxidant
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reduce cancer risk
helps absorb iron from food
Reduces risk of colds?????
probably not
 Linus Pauling’s study
 NutraIngredients
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Vitamin C
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Deficiency: called scurvy
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poor formation of collagen in blood vessels
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weak vessels result in hemorrhages
can be severe and result in lots of blood loss and death
Toxicity: may result in
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kidney stones
rebound scurvy
Destruction of B12
Problems with acid/base balance
Vitamin C: RDA 90/75 mg/day
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Foods rich in vitamin C:
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Smoker’s RDA = +35 mg/day
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1 cup fresh squeezed orange juice: 124 mg
1 cup canned o.j.: 84 mg
Some of vitamin C is sacrificed in reducing
the oxidants of cigarette smoke
Vitamin C intake offers protection against
stomach cancer
Beta-Carotene-provitamin
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Functions
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Weak antioxidant
Enhance immune system
Protect skin and eyes
Deficiency/toxicity
Beta-Carotene-provitamin
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No RDA
Sources
Vitamin A Functions
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Vision: helps with conversion of light
energy to electrical energy in eye
Cell differentiation-maintenance of linings:
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helps produce the CHO normally found in
mucous
Bone growth:
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helps with remodeling growing bones
Vitamin A Deficiency
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One year supply in fat and liver of most people:
So deficiencies are rare
 Bone growth and
 shape changes
remodeling problems
 Linings deteriorate
 GI tract: diarrhea
 Respiratory tract: infections
 urogenital tract: infections, kidney stones
 Impaired
night vision and day vision
Vitamin A Toxicities
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Bones:
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Nervous system
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loss of appetite, irritability, muscle weakness
Liver enlargement
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decalcification, joint pain
jaundice
Blood: RBCs loose hemoglobin
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Bleeding induced easily
Beta carotene and Vitamin A
Vitamin A RDA= 700 RE for
females; 900 RE for males.
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RE= Retinol Equivalent
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Retinol is the active form of vitamin A
Other molecules can be metabolized to make Retinol,
thus retinol equivalents
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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
Selenium
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Functions
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Antioxidant system
Thyroxine and immune function
Deficiency
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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
Selenium – RDA 55 mg/day
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Sources
Nuts
Seafood
Pasta
Disorders related to Oxidation
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Cancer - Definitions
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Cancer: uncontrolled growth and spread of
abnormal cells
Tumor: mass of cancer cells
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benign tumor (non-harmful, non-invasive)
malignant tumor (harmful, invasive)
Metastatic Cancer: spreading
Cancer Facts
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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
Cancer Trends
JNCI, 1999
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1990-1996
All cancer incidence declined by
2.2%
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-4.1% males
-0.5% females
USATODAY.com - Cancer deaths
lowest in 7 decades
US Mortality, 2000
Rank
Cause of Death
No. of
deaths
% of all deaths
1.
Heart Diseases
710,760 29.6
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2.
Cancer
553,091 23.0
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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
37,251
1.5
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9.
Nephritis
Source: US Mortality Public Use Data Tape 2000, National Center for Health Statistics,
Centers
for Disease Control and Prevention, 2002.
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10. Septicemia
31,224
1.3
2004 Estimated US Cancer Deaths*
Lung & bronchus
32%
Prostate
10%
Colon & rectum
10%
Men
285,900
Women
270,600
25%
Lung & bronchus
15%
Breast
10%
Colon & rectum
Pancreas
5%
Leukemia
5%
6%
Pancreas
Non-Hodgkin
lymphoma
4%
6%
Ovary
Esophagus
4%
4%
Leukemia
Liver/intrahepatic
bile duct
3%
3%
Non-Hodgkin
lymphoma
Urinary bladder
3%
3%
Uterine corpus
Kidney
3%
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.
The Cancer Development Process
 Initiation
 Alterations
in DNA
 minutes - days
 Causes:
 radiation
 chemical
 viruses
carcinogens
The Cancer Development Process
 Promotion
“locking” DNA alterations
 failure of DNA repair
mechanisms
 months - years
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The Cancer Development Process
 Cancer
Progression
Uncontrolled growth of cancer
cells
 malignancy and metastasis
 weeks to years
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Cancer Development
http://science.education.nih.gov/supplements/nih1/cancer/activities/activity2_animations.htm
Diet and Cancer Development
 Initiation
 Dietary sources of carcinogens
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aflatoxin mold from peanuts
benzopyrene from charbroiled meats
nitrosamine from cured meats
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AICR Press Corner - Recent News
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Protection
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phytochemicals
antioxidants
dietary fiber
Study will assess effect of tomato oil on precancerous prostate
changes
Diet and Cancer Development
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Promotion
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Fat and PUFA
excess alcohol
Progression
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excess Fat and calories
Alaska Journal of Commerce Online
Diet and Cancer
ACS 2000
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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
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NutraIngredients
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1999 ACS Dietary Guidelines
 Choose
most of the foods you eat
from plant sources.
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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
Trends in Consumption of Recommended
Vegetable and Fruit Servings (5 or more) for
Cancer Prevention, Adults 18 and Older, US, 1994Prevalence
(%)
2000
35
30
25
22
24
24
23
1996
1998
2000
20
15
10
5
0
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.
Cardiovascular Disease (CVD)
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Risk factors
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Smoking
Hypertension
High LDL
Obesity
Sedentary life style
Nutrition Notes: How to fight inflammation Nutrition Notes - MSNBC.com
CVD and Antioxidants
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Scavengers
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Reduction of inflammation
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Donates electrons
Enhances immune system
Reduction of blood coagulation
Vision impairment
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Macular degeneration
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Promising results
Cataracts
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Mixed results