Sources of vitamins (antioxidants) and their mechanism of action
From past articles that I have written on this subject, we understand that the antioxidant defense system is made up of 3 components: the vitamin antioxidant defense system, the enzyme antioxidant defence system and the mineral antioxidant defense system.
We also know that this antioxidant defense system functions by supplying electrons to the free radicals, neutralizing them in the process. Whether there will be oxidative stress and damage to the tissues or not, will be dependent on what is predominant. If the availability of antioxidants outweighs the free radicals, oxidative stress will be prevented. On the other hand, if the free radicals are more than the antioxidants, oxidative stress will occur leading to one disease or the other.
Situations that can lead to a reduction of availability of antioxidants will include; reduced intake of known sources of the vitamins and minerals, over cooking of our food which destroys the nutrients in them, dietary deficiencies of vitamins and minerals in the plants that contain them and certain gastrointestinal diseases such as Crohn’s disease that may hinder absorption of nutrients in the intestines. Crohn’s disease is an inflammatory bowel disease (IBD)
Mechanisms of action of the vitamin antioxidant defense system
There are two types of vitamins that function in the antioxidant defense system: these are the water soluble and fat-soluble vitamins. Each of these types of vitamins will function where there is predominantly water or fats (lipids). For example, there is a double layer of lipids in the cell membranes and Vitamin E, which is a fat-soluble vitamin functions in cell membranes and organelle membranes, neutralizing free radicals. Specifically, 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. Vitamin E, either as a supplement or sourced from plants that contain the vitamin can be used for the prevention of cancer and heart disease. Indeed, for the wellbeing of the heart, the male reproductive organs and the cells generally, plant foods that contain Vitamin E should be consumed regularly.
Vitamin C, a water-soluble vitamin is predominantly found in the extracellular fluid compartment where it donates electrons to free radicals and neutralize them. Vitamin C also donates electrons to Vitamin E that have lost their electrons to free radicals. This function of Vitamin C regenerates Vitamin E and prolongs its life span and its ability to prevent lipid oxidation.
Vitamin A, also a fat-soluble vitamin, is 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.
From the foregoing, we understand that the vitamin antioxidant defense system plays a very significant role as immune boosters and are capable of preventing diseases of the heart, eyes, skin and cancers of various organs of the body. The plant food sources of these vitamins are given below and my advice is that we consume a variety of them regularly.
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.
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)
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.