The antioxidant defence system and free radicals – Part 1
Identifying nutrients [antioxidants] that play a role in the antioxidant defense system.In last week’s edition of The Guardian Newspaper, I presented the free radicals, molecules and atoms that move freely in the tissues and circulation looking for electrons to pick up in order to become stable. Antioxidants are a defense system against free radical builds up, that act by donating an electron to the free radicals, stabilize them and prevent tissue damage by oxidative stress. The antioxidant defence system is an inborn system in the body that checks these free radicals. Tissues and nutrients that are frequently attacked by free radicals are lipids, (Low Density Lipo-proteins/LDLs/bad cholesterol), proteins in the lipid by-layer cell membranes, carbohydrates, cell nucleus, Deoxy ribonucleic Acid (DNA)/genetic material and other organelles in cells.
More often than not, the antioxidant defense system neutralizes and stabilizes the free radicals completely and prevents tissue damage. However, on certain occasions, the ability of the defense system to neutralize the free radicals becomes compromised and the free radicals accumulate and cause damage. This happens when the amount of free radicals in the tissues and circulation is more than the available antioxidant. This state is seen when the intake of nutrients rich in these antioxidants has become deficient, a common occurrence in our diet in this part of the world. The situation is made worse as the idea of supplementing our diet is far-fetched here. Research has shown that more than 80% of the chronic degenerative diseases are caused by free radical damage where the antioxidant defense system has become compromised.
The main free radical produced in the body is the superoxide free radical.When these accumulate as a result of an overwhelmed antioxidant defense system, the superoxide free radicals can react with free fatty acids in a chain reaction to form fatty acid hydroperoxides and other free radicals.
As these accumulate in the absence of antioxidants, the surrounding tissues will begin to suffer from oxidative stress damage. I shall be discussing more about diseases that should have been prevented if the antioxidant defense system functioned optimally.
Components of the antioxidant defense system:
1. The vitamin antioxidant defense system.
2. The enzyme antioxidant defense system.
3. The mineral antioxidant defense system.
1. The Vitamin antioxidant defense system is made up of Vitamins E, C and A (the carotenoids).
Vitamin E: Being a fat soluble vitamin, it is found predominantly in the lipid membranes of cells and organelles.
In these membranes, Vitamin E neutralizes fatty acid hydroperoxide free radicals. It prevents lipid oxidation in cell membranes and protects them against damage. This vitamin protects against heart disease, cancer and age related conditions such as macular degeneration. It also plays a significant role in testosterone production and spermatozoa maturation. It is a must use for men with low sperm count and reduced libido.
Plant sources of vitamin E include:
Vegetables: spinach, kale and collard greens.
Nuts: almonds, pistachios, pecans, walnuts and hazel nuts.
Seeds: pumpkin seeds, sunflower seed and sesame seed.
Seafood/fish: shellfish, shrimps, cray fish, oysters, salmon and herring.
Oils: olive oil, wheat germ oil, sunflower oil, grape seed oil, canola and corn oil.
Vitamin C: This is the predominant antioxidant in the extracellular fluid compartment. It neutralizes free radicals by “donating” electrons to them.
Vitamin C also donates electrons to Vitamin E antioxidants that have lost their electrons to free radicals.
In doing so, Vitamin C helps to regenerate Vitamin E and prolongs its ability to prevent lipid damage in the cell membrane.
Sources of Vitamin C:
Fruits: citrus fruits, tomatoes, strawberries, pawpaw and mangoes.
Vegetables: Brussels sprouts, lettuce, spinach, potatoes and cruciferous vegetables such as cabbage, cauliflower and broccoli. Red and green peppers also contain Vitamin C.
Vitamin A (beta carotene)
This is a fat soluble vitamin, a powerful antioxidant that operates optimally in the fat laden cell membrane. It prevents lipid oxidation of the lipids in the cell membrane. Vitamin A is required for vision and as an immune booster.
It can also enhance skin health and acts as a protection against cancer and aging.
Sources of vitamin A include:
Vegetables: carrots, dark green leafy vegetables such as spinach, kale, Mustard greens, Collard greens, Turnip greens, beet greens and broccoli. Other types of vegetables that are high in vitamin A are Romaine lettuce, pumpkin, sweet red, yellow and green peppers and peas.
Fruits: mango, paw paw (papaya), cantaloupe melon, dried apricots and squash.
Fish/seafood: tuna, mackerel and oysters.
Oils: cod liver oil.
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