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