Antioxidants- basic nutrition

oxidation

loss of an electron

reduction

gain of electron

during metabolism

some lose electrons (oxidation)

free radical

unstable atoms, unpaired electrons an odd number

free radicals are a normal by product of which body processes?

Metabolism (breaking down nutrients to create the energy)
Immune response- causing inflammation

Free radicals formed from exposure to...

carcinogens: air pollution, UV rays, tobacco smoke, chemicals, medical radiation, some viruses, etc.

excessive free radical production

cell damage
‘steal’ electrons from stable atoms creating a chain reaction = more free radicals

antioxidants

donate electrons to free radicals

the "big three" antioxidants

Vit A, C, E

Vitamin E

Fat soluble, 90% stored in adipose tissue, 10% in the cell membrane

Vitamin E functions

- Primary function: antioxidant
- once oxidized Vit E can either excrete or recycle back to active Vit E
- Vit C donates an electron to recycled Vit E
- critical for normal fetal development of nerves and muscles
- improves absorption of Vit A
- Keeps the immune system strong against viruses and bacteria
- Important in the formation of red blood cells and it helps the body use vitamin K.
- Widens blood vessels and keeps blood from clotting inside vessels
- Vit E is added to veg oil and skin care

Vit E protects...

Omega 3 and 6 (PUFA's) and other fatty component of cells from being oxidized= reduced heart disease

RDA of Vit E

15 mg of alpha-tocopherol (most active form)/day
UL= 1,000 mg/d

sources of Vitamin E

spreads and dressing from veg oils, nuts, seeds, and some dark green leafy veggies

excess fo Vit E

usually from supplements
may cause increase for bleeding

medication interaction with Vitamin E

Coumadin and aspirin act as anticoagulants and stop blood from clotting excessively. Vit. E can augment the action of these which may result in uncontrollable bleeding.

Vitamin C

water soluble
- two active forms- ascorbic acid and dehydroascorbic acid

most animals make their own glucose besides...

humans and guinea pigs

functions of vitamin C

1. assist in collagen synthesis
2. assist in synthesis of DNA, bile, neurotransmitters and carnitine
3. assist in synthesis of hormones
- ensures proper levels of thyroxine
- epinephrine, norepinephrine, and steroid hormones
4. antioxidant
- important in extracellular fluid

collagen

a protein critical to all connective tissues
- Collagen assists in preventing bruising, ensures proper wound healing, and is a component of the tissue that mend broken bones.
- Without Vit. C, the body can’t form collagen= tissue bleeding.

Vit C as an antioxidant

1. donates electrons to free radicals to prevent tissue and cell damage
- protects LDL cholesterol from oxidation which reduces CVD risk
- protects us from damage caused by ozone, vaping and cigarette smoke in lungs
2. Regenerates Vit. E after it has been oxidized by donating an electron which enables Vit. E to continue to protect our cell membranes.
3. Enhances immune fxn
4. In stomach- reduces formation of nitrosamines

sources of Vit C

Fresh is best. Steam, microwave, stir-fry to cook.

excess/ deficiency of Vit C

Toxicity not common
deficiency- scurvy will occur after 1 month
s/s bleeding gums, loose teeth, diarrhea, anemia

Those at risk of scurvy

poor, homebound, alcohol and drug abuse

Beta Carotene

Not necessary nutrient
1. inactive from of Vit A- 2 units of Beta carotene= one active unit of Vit A
2. carotenoid- fat soluble orange, red, and deep yellow pigment
3. fat- soluble- fight oxidation in the lipid portions of cell membranes
4. Weak antioxidant, BUT it enhances our immune system and protects the skin and eyes from UV damage.
5. sources: Sources: red, orange, yellow, deep green f/v.
Lightly cooking will increase amount released.

- Vitamin A

- Generic term for a group of similar compounds called retinoids
- Fat soluble. 90% stored in liver.
- Requires retinol-binding proteins to transport to target cells.

Forms of Vit

Retinol- found in animal products. (beta-carotene is converted to this form)
--enzymes convert retinol into Retinoic Acid-
important in cell growth
-Retinal - found in the eye retina

Functions of Vit A

1. healthy vision-
Allows sight under low-lights
Enables us to see color
2. contributes to cell differentiation
3. Immunity (known since 1980’s)
4. antioxidant (not strong)
5. bone growth
6. acne treatment

benefits of Vit A

- maintains health of specialized tissues such as the retina
- aids in growth and health of skin and mucous membranes
- maintains health of specialized tissues such as the
retina
- promotes normal development of teeth, soft and skeletal issues

Excess of Vit A

HIGHLY TOXIC. May develop at 3-4 x’s the RDA.
- Toxicity rarely from food
- S/S- fatigue, decr. appetite, blurred vision, hair loss, liver damage.
- May be reversed if caught early.

sources of Vit A

meats (liver), milk, fortified cereal, margarine

Vit A deficiency signs

dry skin, dry eyes, night blindness, infertility, poor wound healing, acne breakouts, delayed growth, throat and chest infections

Antioxidant chemicals the Body synthesizes

1. Glutathione
- combination of three simple amino acids
cysteine, glycine and glutamine.
-Extracellular fluid
-Sulfur is it’s key chemical component
-Recycled in body
2. Uric Acid- most abundant in blood
-Synthesized from purine metabolism
-Circulates in blood and disables circulating free radicals.
-High concentrations in the blood may cause gout. r/t kidney issues

Free radicals detoxifying enzyme systems

- Protect from f.r. damage
- Minerals as cofactors for the antioxidant enzymes
-Intracellular

superoxide Dismutases (SOD) (enzyme system)

- either manganese, copper, or zinc cofactor
- critical in reducing oxidative stress in life-threatening diseases and reducing inflammation and pain

Catalase (Enzyme)

- Contains Fe as cofactor
- Converts H2O2 to water and oxygen
- Highly efficient

Glutathione Peroxidases

- similar to catalase but different cofactor
- Cofactor- selenium
- convert H2O2 to water & oxygen

benefits of free radicals

- Immune system uses cell-damaging properties of free radicals to kill pathogens
- act as a signaling involved in stress responses
- Must have H2O2 to produce thyroid hormone