FNN Final Exam Prep

Oxidant

A compound which oxidizes other compounds

Pro-Oxidant

A compound which promotes oxidization

Anti-Oxidant

A compound which inhibits/reverses oxidization

Radical

Any atom that contains one or more orbital electrons with unpaired spin states

In-Vivo

"Within the living"

Biological studies that are done testing whole living organisms (could be animals, plants or humans)

In-Vitro

"Within the glass"

Studies on microorganisms, cells or biological molecules usually use test tubes, Petri dishes etc.

In-Vitro antioxidants (also dietary antioxidants)

Vitamin E, Vitamin C, Selenium, carotenoids

(More research is required to verify)

Function of Radical species

Everything we do creates free radicals (eat, exercise, breath)

They potentially play beneficial roles in reactions to viruses and bacteria (minimal)

Generally, they are harmful and we need to counteract them by eating fruits and vegetables.

Attack polyunsaturated fatty acids in lipoproteins and cell membranes (interfering with cellular transport systems)

Damage cell proteins

Can cause DNA mutations

Vitamin C

Needs Vitamin D for absorption

Water soluble

Body can only maintain 22mg/kg of body weight of Vitamin C (rest will be removed from body)

RDA/DRI for Vitamin C

Males = 90 mg

Females = 75 mg

Smokers must ADD 35 mg/day

UL = 2000 mg

Functions of Vitamin C

Preventing scurvy disease (famous)

Production of collagen

Enzyme Cofactor - for reactions requiring reduced metal ions, neurotransmitter synthesis, etc

Reducing power (ability to donate e-) makes it an effective antioxidant for scavenging radical species

Regenerates other antioxidants

Food sources of Vitamin C

Citrus

Tomatoes

Brussels sprouts

Cauliflower

Broccoli

Strawberries

Cabbage

Spinach

Potatoes

Carotenoids

600 carotenoids (34 in humans)

Best Biochemical marker of fruit and vegetable intake (via blood test)

Fat-soluble

Functions of carotenoids

Has pro-vitamin A activity

Carotenoids contribute to making vitamin A

Food sources of Carotenoids

Colourful fruits/veggies

Papaya, peach, melon, yam, squash, carrots, peppers, spinach

Functions of Vitamin E

Prevents oxidation (Synergistic action from selenium in protecting cell membranes from oxidation)

May protect low density lipoprotein from oxidation (oxidative damage associated with CVD, and other diseases)

Important antioxidant for lung cells

Absorption and Excretion of Vitamin E

Fat soluble

Bioavailability estimated at 30%

Absorption: In small intestine

Chylomicrons deliver Vitamin E to the liver -> forming part of Very low density Lipoprotein (cholesterol) and travels to tissues

Excretion: Through feces (low intestinal absorption), sometimes through skin

Deficiency of Vitamin E

Primary deficiency = rare (due to malabsorption, genetic mutations)

Symptoms: peripheral neuropathy, retinopathy, erythrocyte hemolysis (breaking down polyunsaturated fats in red blood cell membranes, causing red blood cell to degrade (hemolytic anemia)

Food sources of Vitamin E

In foods that contain fat

Vegetable oils & spreads: sunflower, safflower, canola, olive

Vegetables, meat, fish, poultry

DRIs for Vitamin E

RDA: Men/women 19-50 yrs = 15 mg/day

UL (19+) 1000 mg/day of any form of supplementary alpha-tocopherol

Functions of Selenium

Needed for production of selenoproteins (14 known) which contribute to antioxidant defense systems

Regulate thyroid hormone action

Regulate redox status of Vitamin C

Food sources of Selenium

Muscle meats

Animal flesh

Animal organs (liver)

Deficiency of Selenium

Very rare

Some evidence found of association with CVD in areas with low soil levels

Selenelosis

Selenium Toxicity

Symptoms; Hair and nail brittleness and loss, garlic breath odour, GI problems

Acute Toxicity for Selenium (symptoms)

Severe GI and Neurological problems

DRIs for Selenium

RDA Males/females 19-50 yrs = 55 mcg/day

UL (19+) = 400 mcg/day

Excess Vitamin C supplementation

Lead to hampered endurance capacity

Excess Vitamin E supplementation

Immunity study → NO difference in race times, Supplementation PROMOTED lipid inflammation.

Excess Vitamin C and E supplementation

Combined study PLACEBO group → MORE lean mass

Function of Water

Delivers nutrients and removes waste

Lubricant & cushion (i.e. joints, eyes)

Medium for chemical reactions

Major constituent of blood volume

Removing heat from the body

Body Water

~50-60% of the human body is water

3 grams of water is stored for every gram of glycogen

~ 70% of muscle tissue is water

• Intracellular (65%)

• Extracellular (35%)

• Intravascular (in blood vessels)

• Intercellular

DRIs for Water

Individualized approach

3.7 L for men daily

2.7 L for women daily

Caveats of water DRIs

Caveat 1: 20% of this requirement can come from food

Caveat 2: All fluids (Milk, juice, soft drinks, caffeinated beverages) count towards this requirement

Caveat 3: The requirement assumes normal activity

Alcohol

Class 1 carcinogen

Associated with 7 cancers

Smaller connections to: Pancreatic, gastric and lung cancers

Coffee and Water (study)

Studies show coffee consumption provided similar hydrating qualities to water

Hyperthermia

Going above normal temperature (~37*C)

40*C is rare

44*C is DEATH