Provides key nutrients needed by the body to neutralize free radicals.
Helps protect against cellular damage. May exhibit anti-aging benefits.
Super ORAC (Primary) Antioxidants are the body’s own natural defense against free radicals.
They scavenge or ‘mop’ them up before they have a chance to harm cells.
What are vitamins?
Complex substances that regulate body processes
Coenzymes (partners) with enzymes in reactions
No calories, thus no energy
Categories Fat-soluble Dissolve in fat Water-soluble Dissolve in water Carried in bloodstream, A, D, E, K C and B-complex vitamins A and D excess can be harmful E and K usually not Excess amounts may cause extra work on kidneys
Vitamin A (and carotenoids)
Protects from infections
Regulates immune system
Fortified milk or other foods
Red, yellow, orange, and dark green veggies (carotenoids)
Vitamin D (the sunshine vitamin)
Promotes absorption of calcium and phosphorus
Helps deposit those in bones/teeth
Regulates cell growth
Plays role in immunity
Sunlight (10 – 15 mins 2x a week)
Salmon with bones
Orange juice (fortified)
Antioxidant, may lower risk for heart disease and stroke, some types of cancers
Protects fatty acids and vitamin A
Foods made from oil (salad dressing, margarine)
Green, leafy veggies
Helps blood clot
Helps body make some other proteins
Body can produce on its own (from bacteria in intestines)
Green, leafy veggies
Some fruits, other veggies, and nuts
Helps produce energy from carbs
Whole-grain and enriched grain products
Changes tryptophan (amino acid) into niacin
Yogurt and milk
Green, leafy veggies
Helps body use sugars/fatty acids
Helps enzymes function normally
Foods high in protein typically (poultry, fish, beef, peanut butter, legumes)
Enriched and fortified grains
Helps body make non-essential amino acids
Helps turn tryptophan into niacin and serotonin
Help produce body chemicals (insulin, hemoglobin, etc)
Folate (folic acid)
Produces DNA and RNA, making new body cells
Works with vitamin B12 to form hemoglobin
May protect against heart disease
Lowers risk of neural tube defects in babies
Controls plasma homocystine levels (related to heart disease)
Fortified and enriched grains and breakfast cereals
Green, leafy veggies
Vitamin B12 (cobalamin)
Works with folate to make RBC’s
In many body chemicals and cells
Helps body use fatty acids/amino acids
Milk, other dairy
Helps body use proteins, carbs, and fats from foods
Wide variety of foods
Whole grain bread
Helps produce energy
Helps the body use proteins, fat, and carbs from food
Found in almost all foods
Meat, poultry, fish
Whole grain cereals
Helps produce collagen (connective tissue in bones, muscles, etc)
Keeps capillary walls, blood vessels firm
Helps body absorb iron and folate
Heals cuts and wounds
Protects from infection, boosts immunity
Other fruits, veggies
Rickets (children and vitamin D)
Osteoporosis/osteomalacia (vitamin D)
Scurvy (vitamin C)
Night blindness (vitamin A)
What are minerals?
Regulate body processes
Give structure to things in the body
No calories (energy)
Cannot be destroyed by heat
Categories of minerals
Electrolytes (sodium, chloride, potassium)
Helps blood clot
Regulate energy metabolism
Component of bones, teeth
Part of DNA, RNA (cell growth, repair)
Almost all foods, especially protein-rich foods, contain phosphorus
Cancer initiation and promotion is associated with chromosomal defects and oncogene activation. It is possible that endogenous free radical reactions, like those initiated by ionizing radiation, may result in tumour formation.
The free radical diseases
Atherosclerosis may be due to free radical reactions involving diet-derived lipids in the arterial wall and serum to yield peroxides and other substances. These compounds induce endothelial cell injury and produce changes in the arterial walls .
Vitamin E is a fat-soluble substance present in all cellular membranes and is mainly stored in adipose tissue, the liver and muscle. Vitamin E is a principal antioxidant in the body and protects polyunsaturated fatty acids in cell membranes from peroxidation.
Vitamin E and cancer
Besides being a free radical scavenger, vitamin E at high intakes enhances the body's immune responses. Vitamin E also inhibits the conversion of nitrites in the stomach to nitrosamines, which are cancer promoters.
Vitamin E and cardiovascular disease
Vitamin E intakes are associated with lowered risk of angina and mortality from heart disease.
Vitamin E and neurological disorders
Supplementation with vitamin C and E might be of benefit in slowing the progression of Parkinson's disease.
Vitamin C, or ascorbic acid, is a water-soluble vitamin. This vitamin is a free radical scavenger, it is considered to be one of the most important antioxidants in extra cellular fluids. Its protective effects extend to cancer, coronary artery disease, arthritis and aging.
Vitamin C and cancer
Vitamin C is effective in protecting tissues against oxidative damage. It suppresses the formation of carcinogens. Numerous studies have reported the protective effect of fruit and vegetable consumption on incidence of cancer . This is mainly attributed to the protective effect of vitamin C against cancer.
Vitamin C and cardiovascular disease
Vitamin C may lower total cholesterol in the blood, thus reducing the risk of cardiovascular disease. Coronary heart disease mortality is higher in those with blood vitamin C levels that are near or in the deficient range.
Vitamin C and cataracts
High intake of fruits and vegetables which are rich sources of ascorbic acid appear to be protective too. In several studies, cataract patients were shown to have low vitamin C and E intakes and low plasma vitamin C levels.
Carotenoids are a group of red, orange and yellow pigments found in plant foods, particularly fruits and vegetables.
Some carotenoids like b-carotene act as a precursor of vitamin A; others do not.
Superoxide Dismutase (SOD) is essential for the body and is: A metalloprotein – containing several sub units organised around a metallic group An enzyme – the antioxidant enzyme SOD eliminates, in a continuous way, superoxide radicals, precursors of other oxygen reactive forms (secondary free radicals) And most importantly
Why is SOD necessary? SOD acts at the source. It is the first and one of the major components of the body’s antioxidant system.
SOD is a powerful and efficient antioxidant:
1 iu SOD eliminates 1μmol superoxide/min and SOD has an active lifespan of several days!
In the end, billions of superoxide molecules destroyed
SOD is a primary antioxidant and possibly our most important one
Reactive oxygen species: formation of secondary free radicals
Hydroxyl radical induces the formation of
secondary free radicals:
Secondary free radicals or organic peroxides are very toxic
They increase oxidative reactions which are propagated from one to the next
They are directly responsible for cell alterations and destruction
They indirectly participate in the inflammation process
The BALANCE Between Pro-Oxidants and Antioxidants Pro-Oxidants ( Reactive Oxygen Species Free Radicals) Antioxidants OXIDATIVE STRESS Cell & Tissue Damage Protection / Tissue Repair Antioxidants Cell / Tissue Damage Oxidants
Antioxidant systems: the primary antioxidants
The primary antioxidants :
are endogenous molecules
act at the source (where free radicals are created)
are enzymes which continuously eliminate the free radicals just formed:
- SOD eliminates the superoxide ion
- catalase and the glutathione peroxidase eliminate hydrogen peroxide
Antioxidant systems: the secondary antioxidants
The secondary antioxidants
are exogenous molecules , carried by food (vitamins A, C, E, polyphenols…)
they scavenge the secondary free radicals
one molecule of a secondary antioxidant traps one free radical molecule – a 1:1 relationship
Oxidants and antioxidants in the body Under normal circumstances and conditions, the body’s endogenous antioxidant systems are able to neutralize the oxidant (free radical) molecules Therefore -> no oxidative stress means -> no cell damage
Oxidative stress… … is the result of an imbalance between oxidant and antioxidant production increase of free radicals -> antioxidant systems overpowered
Oxidative stress: consequences
A break in the equilibrium caused by…
UVA and B
Stress, overwork, diet
Pollution, chemicals, cigarettes
… puts the body into oxidative stress: -> attacks on cell constituents (cell membranes, protein, lipids DNA) Only solution: we must combat free radicals
O 2 Figure 5. Pathways for the formation of reactive oxygen species Superoxide dismutase Haber-Weiss reaction; Fenton reaction Singlet oxygen Superoxide radical anion Peroxyl radical lipid radical lipid peroxyl radical UV light heme Fe CoQ 1 O 2 NADPH or CoQ O 2 - H 2 O 2 H + H + HOO Lipid (LH) L H 2 O O 2 LOO OH Fe 2+ H 2 O, H +
The fight against secondary free radicals … … occurs with the secondary antioxidants (vitamins A,C, E, polyphenols etc) BUT antioxidants (acting 1 against 1) are quickly outnumbered and cannot eliminate a continuous and strong production of free radicals
Secondary antioxidants are vital but just slow down the oxidative stress – we need to do something extra…
Functions of Pentose Phosphate Pathway
NADPH for biosynthetic pathways (e.g., synthesis of fatty acids and cholesterol);
2) NADPH for maintaining glutathione in its reduced state .
3) Pentose sugar for synthesis of nucleic acids
Table 1 . Reactive Oxygen Species and Antioxidants that Reduce Them Reactive Species Antioxidant Singlet oxygen 1 O 2 Vitamin A, vitamin E Superoxide radical (O 2 - ) superoxide dismutase, vitamin C Hydrogen peroxide (H 2 O 2 ) Catalase; glutathione peroxidase Peroxyl radical (ROO ) Vitamin C, vitamin E Lipid peroxyl radical (LOO ) Vitamin E Hydroxyl radical (OH ) Vitamin C
Figure 6. Reactions of glutathione reduction and oxidation H 2 O 2 glutathione peroxidase 2 H 2 O 2 GSH GSSG glutathione reductase NADPH + H + NADP + pentose pathway
SUMMARY OF ANTI-OXIDANT ENZYMES Glutathione peroxidase: 2 GSH + H 2 O 2 GSSG + 2 H 2 O Uses selenium as a cofactor Catalase : 2 H 2 O 2 H 2 O + O 2 Superoxide dismutase: 2 O 2 - + 2H + H 2 O 2 + O 2 Mitochondrial - Mn 2+ cofactor Cytoplasmic – Cu 2+ -Zn 2+ cofactors; mutations associated with familial amyotrophic lateral sclerosis (FALS) Lipid Peroxidase: removes LOOH
selenocysteine in glutathione peroxidase
intake may be related to lower cancer mortality
cancer patients have lower plasma Se levels
risk may be higher in those with low Se intake
AZCC study – reduced incidence of prostate, colon, lung cancers
toxicity (> 1 mg/day) results in hair loss, GI upset, nerve damage
NUTRITIONAL CORRELATE: SELENIUM
Figure 7. Antioxidant cascade Reduced forms/reduction Oxidized forms/oxidation rxn 9 rxn 7 rxn 1 rxn 6 rxn 5 rxn 4 Vit E red VIT E ox Vit C red VIT C ox LOOH lipid peroxyl radical LOO Glutathione red (GSH) NADP + NADPH + H + Glucose-6-P Ribulose-5-P Pentose phosphate pathway (rxn 8) +ROOH rxn 2 Glutathione ox (GSSG) H 2 O 2 2H 2 O hydroxyl radical (OH ) superoxide radical (O 2 - ) reduced products
Medical Scenario: If the antioxidant protective system in the red blood cell becomes defective, hemolytic anemia occurs; that is red blood cells undergo hemolysis and their concentration in the blood decreases. Such is the case if glucose 6-phosphate dehydrogenase is defective in the pentose phosphate pathway. In individuals whose glucose 6-phosphate dehydrogenase is defective, there is insufficient NADPH produced in red blood cells to maintain the ratio of reduced glutathione to oxidized glutathione at its normal value of well over 100. Hence, peroxides destroy the red cell membrane because of the limited protective mechanism in these cells.