Cut the apple in half and it turns brown. The copper penny suddenly turns green and the iron nails rust when placed outside. What do all these events have in common? These are examples of a process called oxidation. Soaking the sliced apples in lemon juice, however, slows down the speed of their browning. This is because the vitamin C in lemon juice slows down the rate of oxidative damage.
Since its discovery 65 years ago, vitamin C has become known as the "miracle worker". Due to its role in collagen formation and other life-supporting functions, vitamin C functions as a key nutrient for the immune system and a powerful free-radical fighter. This dual nutrient has been proven to prevent a variety of diseases, from everyday illnesses like the common cold to devastating diseases like cancer.
Water-soluble vitamin C is known in the scientific world as ascorbic acid. This term means "no scurvy." We rely on ascorbic acid for many aspects of biochemical function. However, humans are just one of the few animal species that cannot supply vitamin C on their own. Like other animals, including primates and guinea pigs, we are forced to obtain this nutrient from food and our daily diet.
Vitamin C can increase your body's resistance to various ailments, including infections and certain types of cancer. It strengthens and protects the immune system by stimulating the activity of antibodies and immune cells such as phagocytes and neutrophils.
Vitamin C as an antioxidant helps reduce the activity of free radicals. Free radicals are byproducts of normal metabolism and can damage cells and cause aging, degeneration, and cancer. It's no surprise that vitamin C is used to treat cancer. In high doses, vitamin C is sometimes given intravenously as part of cancer treatment.
Vitamin C also helps prevent free radical damage to the lungs and protects the central nervous system from such damage. Free radicals are molecules with unpaired electrons. In this state, they are very responsive and destructive to everything in their path. Free radicals cause many diseases, but they are part of the body's chemistry.
The main role of vitamin C as an antioxidant is to neutralize free radicals. Ascorbic acid is water-soluble, so it can act both inside and outside the cell to fight free radical damage. Vitamin C is an excellent source of electrons. Thus, "it can donate electrons to free radicals such as hydroxyl and superoxide radicals, suppressing their reactivity."
The versatile vitamin C works in conjunction with glutathione peroxidase, a major free-radical-fighting enzyme, to activate the fat-soluble antioxidant vitamin E. In addition to acting as a direct scavenger of free radicals in body fluids, vitamin C also contributes to the antioxidant activity of lipids.
However, optimal health requires a balance of free radical formation and antioxidant defenses. One of the functions of vitamin C is to acquire and eliminate these free radicals.
However, research has shown that vitamin C can act as a pro-oxidant. In other words, vitamin C can act under certain conditions and in the opposite direction concerning its purpose. This has caused concern for thousands of people who supplement their diet with vitamin C ... but that's another story.
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