| 1 Oxidative Tissue Injury caused by
2 Causes chain reactive damage to: | 1 Oxygen free radicals
unpaired electrons
superoxide O2-.
hydroxy free radical OH.
hydrogen peroxide
2 Cell membranes
Proteins
DNA |
| Oxidative Tissue Injury is Associated with | 1 Coronary Heart Disease
oxidized LDL-cholesterol
2 Carcinogenesis
3 Chemical Toxicity
4 Auto-immune dieseases
5 Aging |
| Sources of Oxygen Free Radicals | 1 Normal energy metabolism
2 D-amino acid metabolism
3 Metabolism of foreign chemicals
4 Ozone, nitrogen oxides, UV light, smoke, radiation, etc... |
| Cellular Antioxidants | 1 Antioxidant Enzymes
2 Nutritional Antioxidants
- Vitamin E
- Carotenoids and other plant phytochemicals
- Vitamin C |
| Antioxidant Enzymes
1 removes hydrogen peroxides
2 removes superoxide radicals
3 removes peroxides | 1 Catalase (iron)
2 Superoxide Dismutase (Cu, Zn)
3 Glutathione Peroxidase (Se) |
| Tocopherols
Dietary sources: widespread, highest in plant oils
Deficiency:
- rare in adults
- premature infants: hemolytic anemia
Function: free radical scavenger in membranes
RDA: 8-10 mg/d
“Research dosages”: 400-800 mg/d
Toxicity: rare, may be non-toxic below 1000 mg/d | Vitamin E |
| Vitamin C Functions | 1 Antioxidant
2 Collagen synthesis
3 Synthesis of neurotransmitters, thyroxine
4 Aids in absorption of dietary iron |
| 1 Vitamin C toxicity dose: __
2 causes __ | 1 > 1000 mg/d
2 diarrhea
kidney stones
promotes “iron overload” toxicity
Interfers with important lab tests
blood in stools (colon cancer)
urinary and blood glucose (diabetes) |
| Functions:
- -Hemoglobin
- Myoglobin
- Iron enzymes
- -catalase
--electron transport system
Deficiency
Anemia
fewer, smaller, paler red blood cells
fatigue
5-10% of US premenopausal women
up to 40% of population in developing countries | Iron |
| Iron Deficiency Causes | 1 Blood loss
- menstrual blood loss
- parasites and bleeding ulcerations
2 Inadequate dietary intake
RDA men = 10 mg/d
RDA women = 15 mg/d
US usual intake 6 mg/1000 Cal |
| IRON Dietary Sources | 1 Heme Iron
- meats (Hb & Mb)
- 20-30% absorbed
2 Non-heme Iron
- plants
- inorganic iron
- 1-10% absorbed
- vitamin C increases absorption
- iron cookware |
| Iron Overload Toxicity CAUSES
May occur in 10% of men | 1 Children (accidental poisoning)
2 Men and post-menopausal women
3 Genetic “defect”
4 Excess iron is a pro-oxidant.
- tissue injury
- oxidized LCL-C |
| Iron Overload Toxicity Treatment | 1 avoid iron containing supplements
2 avoid excess vitamin C supplements
3 bleeding or blood donation |
