The human body is a dynamic chemical system. Millions of chemical reactions occur in this marvelous piece of creation per second of its existence. An important element in the body’s metabolism is oxygen, as it is to most life on this planet. Although oxygen is required for life, there is an obvious paradox, since oxygen is a highly reactive element that can damage living systems by forming what are known as free radicals (for example, reactive oxygen species like hydrogen peroxide).
Detrimental Effects of Free Radicals
To protect important constituents of a cell like DNA, proteins and lipids from oxidative damage, the body has its own elaborate antioxidant system. It should, however, be noted that all free radicals are not harmful to the body. In fact they are required for certain processes like destruction of engulfed microorganisms by phagocytic cells or in cell signaling. Free radicals are implicated in many diseases like cancers, emphysema, liver damage, Parkinson’s, Alzheimer’s and aging.
Antioxidants – Sources and Effects
The body gets most of the antioxidants required from diet, but today’s stressful lifestyle and not-too-healthy eating habits may provide less than normal dosage of antioxidants leading to various problems associated with oxidative stress. Thus it is imperative that we consume foods rich in natural antioxidants to avoid such problems. Natural antioxidants are a diverse group of chemicals found in fruits and vegetables.
Most notable effects of certain antioxidants and their sources are as follows:
Vitamin C (citrus fruits, tomatoes, strawberries, potatoes) directs antioxidant activity and also inhibits nitrosamine (a dangerous carcinogen) formation.
Melatonin (mustard, fenugreek, flax) is a powerful antioxidant that can cross the blood-brain barrier.
Vitamin E (vegetable oils such as corn, olive, palm, peanut) is an important lipid-soluble antioxidant.
Carotenoids (apricots, papaya, mangoes, pumpkin) have anti-cancer activity.
Lycopene (tomatoes, watermelon, pink grapefruit) has protective effects against prostate and other cancers
Anthocyanins (blueberries, raspberries, blackberries, grapes, cherries) prevent DNA damage from carcinogens.
Allyl sulfides (garlic, onions) have anti-carcinogenic activities.
Monoterpenes (carrots, cabbage, cucumber, peppers, basil) have protective enzyme activity.
Flavonoids (eggplant, soybeans, berries) prevent various types of cancers.
Phenolic acids (parsley, carrots, tomatoes, eggplant) encourage antioxidant activity and also help production of protective enzymes.
Catechins (green tea, berries) are antioxidants which protect against cancers of the gastrointestinal system.
Some experts believe that although natural foods like fruits and vegetables contain a tremendous variety of antioxidants, they are not present in the amount normally required by the body, which means that a person will have to consume large amounts of fruits and/or vegetables to get the required quota of antioxidants. This is where dietary supplements come into picture. But these should be taken under medical supervision lest they harm the body instead of benefiting it.
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