antioxidants

• Antioxidants

  Substances that may protect your cells against the effects of free radicals
• Free radicals

  Molecules produced when your body breaks down food, or by environmental exposures like tobacco smoke and radiation
• Free radicals can damage cells, and may play a role in heart disease, cancer and other diseases
• Antioxidant substances

  • Beta-carotene
  • Lutein
  • Lycopene
  • Selenium
  • Vitamin A
  • Vitamin C
  • Vitamin E
• Antioxidants are found in many foods, including fruits and vegetables, nuts, grains, and some meats, poultry and fish
• Laboratory and animal research have shown that antioxidants help prevent the free radical damage that is associated with cancer
• Antioxidants neutralize free radicals as the natural by-product of normal cell processes
• Free radicals

  Molecules with incomplete electron shells which make them more chemically reactive than those with complete electron shells
• Exposure to various environmental factors, including tobacco smoke and radiation, can also lead to free radical formation
• Oxygen

  The most common form of free radicals in humans
• When an oxygen molecule (O2) becomes electrically charged or "radicalized" it tries to steal electrons from other molecules, causing damage to the DNA and other molecules
• Over time, such damage may become irreversible and lead to disease including cancer
• Antioxidants "mop up" free radicals

  They neutralize the electrical charge and prevent the free radical from taking electrons from other molecules
• Antioxidants

  Classified into two broad divisions: water-soluble (hydrophilic) and lipid-soluble (hydrophobic)
• Water-soluble antioxidants react with oxidants in the cell cytosol and the blood plasma, while lipid-soluble antioxidants protect cell membranes from lipid peroxidation
• Antioxidants may be synthesized in the body or obtained from the diet
• The relative importance and interactions between different antioxidants is a very complex question, with the various metabolites and enzyme systems having synergistic and interdependent effects on one another
• The amount of protection provided by any one antioxidant will depend on its concentration, its reactivity towards the particular reactive oxygen species being considered, and the status of the antioxidants with which it interacts
• Industrial uses of antioxidants

  • Stabilizers in fuels and lubricants to prevent oxidation, and in gasolines to prevent the polymerization that leads to the formation of engine-fouling residues
  • Prevent the oxidative degradation of polymers such as rubbers, plastics and adhesives that causes a loss of strength and flexibility
  • Protect polymers containing double bonds in their main chains from oxidation and ozonolysis