By Michael Okubena


  • In medical terms antioxidants definition is - naturally occurring molecules found in various forms such as vitamins, minerals or compounds in a variety of foods that help fight free radicals which cause oxidative damage to blood cells and DNA in the body. If left unchecked, these free radicals can have harmful effects on our health as they accelerate the processes of aging, cause fatty substances or plaque to build up on artery walls increasing risk of heart diseases, cause damage to the cells in our body and also hinder smooth movement of blood to all parts of the body. 

    Antioxidants themselves get oxidized when they block the process of oxidation by neutralizing free radicals, thus there is constant need of the body to replenish antioxidant resource. They are found in substances such as vitamin E, vitamin C or beta carotene which protect the body cells from the damaging effects of oxidation and therefore help to maintain our general health and wellbeing.

    Antioxidants are very beneficial as they help to boost energy, reverse the aging process and nourish the skin by supplying purifying agents in the blood. They play a vital role in preventing the development of chronic diseases such as cancer, heart disease, stroke, rheumatoid arthritis, Alzheimer disease and cataracts.  Antioxidants are also known to lower blood pressure.

    Antioxidants - How they work

    Oxidation, a natural process that occurs within our body's cells, can produce reactive substances called free radicals. Free radicals can damage our body cells. This procedure leads to oxidation of antioxidants and thus makes it necessary for the body to replenish antioxidant resources on a constant basis.  Antioxidants can stabilize free radicals before they damage our body cells. There are two ways by which antioxidants can fight free radicals and prevent oxidation:

    • Chain-breaking method

    Antioxidants help to terminate the chain building process by free radicals, which lead to the creation of a stabilized radical. Generally, free radicals roam around in our body trying to release or get an electron. When their task is accomplished, a second radical is formed which again try to release or get electron. Thus excessive free radicals are formed in the body due to this chain building process. Antioxidants play a crucial role in breaking this chain and stop the production of more unstable products inside the body.

    • Oxidation deterrence

    The main reason behind the creation of chain of free radicals is oxidation process. Oxidative process initiates the process of multiple chain building of free radicals. Antioxidants not only help break the chain of free radicals, but can also help prevent oxidative process. Rate of chain initiation is generally reduced by enzymes such as superoxide dismutase, catalase and glutathione peroxidase. These enzymes search for the chain initiating free radicals and try to neutralize them and prevent an oxidation chain, and thus prevent oxidation process. Metal radicals such as iron and copper also initiate the oxidative process, but these antioxidant enzymes stabilize them and prevent oxidation.

    Antioxidants include some vitamins (such as vitamins C and E), some minerals (such as selenium), and flavonoids, which are found in plants. The best sources of antioxidants are fruits, vegetables and whole grains.

    Types of antioxidants

    Antioxidants are found in nutrients such as Vitamin E, Vitamin C, Beta-carotene, Selenium and enzymes such as Superoxide dismutase, Catalase, Glutathione peroxidase etc. There are several types of antioxidants and each type is unique in terms of its structure and antioxidant function. Some of these types are listed below:

    • Glutathione

    The body produces and stores the largest amount of glutathione in the liver, where they play a crucial role in detoxifying harmful compounds so that they can be removed from the body through bile. This antioxidant helps prevent cancer especially of the liver and protects the cells throughout the body. Glutathione also maximize the disease fighting power of the immune system, as liver supplies this powerful antioxidant directly in the bloodstream which keeps red blood cells and white blood cells healthy. They play a vital role in converting carbohydrates into energy and prevent the buildup of oxidized fats that may contribute to atherosclerosis. Vegetables and fruits are the best source of glutathione.

    • Melatonin

    Melatonin is an antioxidant hormone that is secreted into the bloodstream by the pineal gland. The pineal gland is a small, pea sized structure near the center of the brain. This antioxidant helps to slow the aging process and prevents chronic diseases such as cancer, heart disease and Alzheimer disease. Melatonin helps to maintain body’s natural biorhythm. This potent antioxidant also helps to alleviate cluster headaches, boosts immune system’s ability to stop tumor from spreading throughout the body. Melatonin is more beneficial for women as this antioxidant controls the menstrual cycle and release of female reproductive hormones. During old age the body’s ability to produce melatonin decreases, hence taking melatonin supplements may prove beneficial.

    • Lipoic acid

     Lipoic acid acts as a universal antioxidant and it is naturally produced by the body. It helps to protect the body against harmful effects of free radicals and enhances the activities of other antioxidants in the body. Lipoic acid has anti-inflammatory and Neuro-protective capabilities that make it effective in slowing the aging of the brain and treating Alzheimer's disease. It also plays a vital role in normalizing blood sugar levels and thus prevents serious complications from diabetes. It is an essential part of the metabolic machinery as it helps to convert glucose into energy for the body requirements. Lipoic acid supplements helps to replenish lipoic acid storage, as lipoic acid decreases with advancing age.

    • Bilberry

    It is one of the most effective antioxidant herbs which keep capillaries strong, protect against night blindness, cataracts, and improve circulation. It prevents radical damage to collagen and collagenous tissue and thus prevents diseases such as gout, periodontal diseases and osteoarthritis. Bilberry extracts are quite famous as they have anti-carcinogenic effects.

    • Acai Berry

    Acai berry is a potent antioxidant, as it contains essential omega 3 fatty acids and adequate amount of vital amino acids. It improves skin condition and helps clear up skin related problems as it allows the skin to regenerate faster and more efficiently. The fatty acids that are present in Acai berry help to reduce the risk of symptoms associated with heart disease. Acai berry also neutralizes free radicals and repairs damage that free radicals can do to the body. It also improves digestive health and burns unwanted mass helping in losing weight quickly. Acai berry is also a rich source of protein and dietary fiber.

    • Coenzyme- Q10 (Coq10)

    The Coq10 or coenzyme-Q10 is a super antioxidant nutrient which is used in prevention and treatment of various forms of heart diseases. It is highly effective in preventing the oxidation of low-density lipoprotein cholesterol (LDL) that leads to atherosclerosis (2, 6-8). An adequate level of Coq10 is essential for proper muscle functioning and improves the condition of people suffering from muscular dystrophy. Coq10 also maintains oral health and keeps gums healthy. Meat, dairy products, eggs, cereals and vegetables are best source of Coq10. Several studies have shown that adequate Coq10 level in the body helps to lower the deterioration rate of Parkinson’s disease. It also plays a potential role in the treatment of neurodegenerative disease.

    • Minerals

    Our body needs adequate amount of dietary minerals for vital body processes and developments. Some of the important minerals needed are calcium, iron, magnesium, selenium, sodium and zinc. They act as vital components for enzymes and hormones. As minerals cannot be produced by the body, they need to be acquired through diet. Minerals play an important role with respect to energy metabolism, collagen formation, bone/teeth mineralization, antioxidant activities, detoxification, cell excitability, and blood clotting. Nuts, legumes, wholegrain foods, green leafy vegetables and milk products provide most of the minerals in our diet.

    • Carotenoids

    Plants produce strong antioxidants to prevent sunlight, ultraviolet radiation and other environmental carcinogens from damaging their cellular system. They are one of the most effective types of antioxidants and daily intake of them is important to avoid harmful diseases. The most beneficial and effective carotenoids are alpha-carotene, cryptoxanthin, Beta carotene, zeaxathin, lycopene.

    • Flavonoids

    Flavonoids are non-nutrient compounds found in fruits, vegetables, herbs, grains, nuts and beverages. They are known as polyphenolic compounds. Red wine, green, black or white teas are a rich source of flavonoids. Flavonoids are beneficial as they inhibit low density lipoprotein (LDL) oxidation by free radicals and prevent oxidative stress. They also have anti-bacterial, anti-viral, anti-tumor, anti-inflammatory and antiallergenic effect. Some of the types of flavonoids are catechins, reserveratrol and proanthocyanidins.

    • Isoflavones

    Isoflavones are found in soybeans and other legumes and have various health benefits. A diet supplemented with isoflavones has been shown to reduce cardiovascular risk factors in postmenopausal women with Type 2 diabetes. Isoflavones also provide protection against breast cancer, prostate cancer, menopausal symptoms, heart disease and osteoporosis. The important types of isoflavones are Genistein and Daidzein.

    • Goji Berries

    Goji berries are well known for their natural antioxidant properties which have far reaching abilities against the damaging effects of free radicals. These antioxidants have been shown to reduce risk of heart disease and neurological diseases. Goji berries help to improve eyesight, fertility and sexual function and are beneficial for proper functioning of liver. The extracts of Goji berries play a crucial role in preventing expansion of cancer cells, lowering blood glucose and reducing cholesterol levels. Goji berries also strengthen the immune system of our body by boosting polysaccharides that control important defense system. They also contain essential fatty acids, which are required for the production of hormones and for the smooth functioning of the brain and nervous system.

    Antioxidants benefits

    Antioxidants are nutrients that help protect our cells from damage caused by free radicals that attack healthy cells. They help to terminate the chain building process by free radicals, which lead to the creation of a stabilized radical. Antioxidants are generally found in substances such as vitamin E, Vitamin C or beta carotene which protect body cells from the damaging effects of oxidation and therefore help to maintain our general health and wellbeing. Antioxidants are blessed with several benefits, some of them are

    • Antioxidant enzymes such as vitamins C and E, carotenoids especially lutein and zeaxanthin and zinc may protect the eyes against harmful ultraviolet rays from the sun.
    • Dietary antioxidants like blueberries, acai berries, and green tea have beneficial effect on neurodegenerative diseases like Alzheimer and Parkinson disease.
    • Antioxidants help fight heart disease, tumor growth and reverse the process of aging and increase longevity.
    • Antioxidants play a beneficial role in maintaining and nourishing healthy skin tone by reducing wrinkles and preserving the skin’s natural health. 
    • As they prevent the cellular damage caused by the free radicals, they slow or may stop the growth of cancer cells.
    • They also prevent radical damage to collagen and collagenous tissue and thus prevent diseases such as gout, periodontal diseases and osteoarthritis.
    • Antioxidants play a major role in keeping our immune system strong for fighting against viruses, germs and other harmful substances. 

    Antioxidant diet

    Antioxidants are molecules that slow down or prevent the deterioration and damage of cells in the body. If the antioxidant levels in the body are not adequate, the harmful effect of it can cause oxidative stress and may damage or even kill off cells. A healthy diet as well as regular exercise goes a long way in keeping a person healthy. In addition, consumption of antioxidant foods also increases the antioxidant levels of the body helping to keep other ailments at bay. Sufficient amount of antioxidants can be met by including foods and drinks rich in antioxidants.

    • Antioxidant foods

    Antioxidant fruits

    • Apricots, bananas, Clementine, yellow grapefruit, oranges, yellow peach, pears, honeydew and cantaloupe melons, pineapple, red plum, tangerine, water melon contain ample amount of potent antioxidants that help in maintaining health skin tone.
    •  Blackberry, blueberry, raspberry, cherry,redcurrant, acai berry, Goji berries, coffee berry are rich in proanthocyanidins, antioxidants that can help prevent heart disease and are beneficial in boosting immunity.
    •  Kiwi fruit, black and white grapes, loquat, fig, prickly pear, black and green olives are good sources of antioxidants which helps to protect the body against harmful effects of the free radicals.

    Antioxidant vegetables and meat

    • Carrot, cauliflower, celery, chicory, cucumber, eggplant, endive, fennel, green bean, leek, green lettuce, mushroom are some of the vegetables which are rich in antioxidants and help to maintain heart health. 
    • Dark green leafy vegetables, salmon, tomatoes, tea, nuts, beans and whole grains are some good source of antioxidants. 
    • Yellow onion, chili and red bell peppers, potato, pumpkin, radicchio, Swiss chard stalk, red radish, spinach, salad and sauce tomatoes, turnip tops and zucchini are best sources of antioxidants. 
    • Artichoke, arugula, asparagus, avocado, beet, red cooked beetroot, broccoli, green and Savoy cabbages are excellent sources of antioxidants. 
    • Fish, chicken, lamb, oyster and tuna are good antioxidant sources. 

    Antioxidant drinks

    • Antioxidants in fruits - Pomegranate Juice, apple juice, orange juice, lemon juice, red wine, Concord grape juice, Blueberry juice, Black cherry juice, Acai berry juice, Cranberry juice and Goji juice are best antioxidant drinks available. 
    • Antioxidants in tea and coffee - Green tea, Coffee, ice tea, herbal tea are excellent drink sources which provide vital antioxidant properties.  
    • Antioxidant and red wine - A glass of red wine can keep the heart beating longer and stronger. Red wine contains resveratol and quercetin; potent antioxidants that help boost heart health by fighting against free radicals, reduce platelet aggregation and help blood vessels remain open and flexible. 

    Antioxidants and weight loss

    In human beings, body fats are stored in adipose tissues which contain lipids that are needed to transform nutrients into energy. Toxins are generally released through the digestive process and fat cell store them. Antioxidants improve digestive health by destroying harmful toxins and burn unwanted mass which help in losing weight quickly.

    Green tea is a potent antioxidant which produces thermogenesis and thus leads to increased energy usage and fat oxidation which in turn helps the body burn excess fat resulting in weight loss. Supplements containing extracts of substances like Acai berry and red wine (resveratrol) can be a good alternative for weight loss. During the fat burning process, antioxidants provide nutritional support to the body as it need to be strong and energized to handle the process.

    Antioxidants skin

    Skin is a large and vital sensory organ and acts as defense against all kinds of attacks on the body,       such as bacteria, viruses, fungi and foreign invaders. It contains vital fluids which do not evaporate uncontrollably and are essential for maintaining body temperature. In addition, the skin produces and stores vitamin D, which is necessary for absorbing calcium. 

    Since skin is constantly exposed to sunlight and pollutants, it is constantly affected by the formation of free radicals. People who do not protect skin properly against pollutants and free radicals are at a higher risk of developing skin cancer. Free radicals can also damage DNA, damage blood cells, create age spots and wrinkles and depress the immune system.

    Including a diet rich in antioxidants or taking antioxidant supplements are the most effective ways to protect skin from harmful damage done by pollutants and free radicals.

    • Antioxidants neutralize internal and external forces that produce free radicals, which is the main cause of aging. 
    • Vitamins E or Vitamin C are some of the essential antioxidant vitamins which help prevent skin cancer and keep skin firm and young looking.
    • Antioxidants can also help prevent symptoms such as dry skin, oily skin, chapped lips, acne-prone skin and puffed or tired eyes. 

    Antioxidant Vitamins

    Antioxidants which are found in nutrients such as Vitamin E, Vitamin C, Beta carotene have potential health promoting properties. Antioxidants are also known to prevent oxidation of low density lipoproteins or ‘bad cholesterol’ and thus stop the development of fatty buildups on the artery walls. This bad cholesterol (LDL) is a major reason for heart attacks, strokes and atherosclerosis.

    • Vitamin A helps to keep eyes, skin and mucous membranes moist and also neutralizes free radicals in the body that cause tissue and cellular damage.
    • Vitamin B Complex (which includesB vitamins thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate) acts as an antioxidant helping fight free radicals. Vitamin B is a powerful antioxidant and is an excellent vitamin source for heart health, nervous system as well as muscle function, conversion of fatty acids and amino acids into hormones, proteins, and enzymes. It is a great energy booster.
    • Vitamin C is a water soluble antioxidant vitamin which protects the body and the skin against harmful environmental pollutants. Citrus fruits and their juices, acai berries, goji berries, grape seed extract are best sources of Vitamin C. 
    • Vitamin D is the most potent antioxidant vitamin which helps the body to absorb and use calcium from food and supplements. It aids in bone and tooth formation and supports muscle and nerve function. It is essential for blood clotting – crucial otherwise a lot of blood can be lost even by a small cut or bruise and the person would die immediately.
    • Vitamin E acts as a primary protector against oxidation and it is a vital and most efficient fat soluble antioxidant vitamin.
    • Vitamin K is the vital antioxidant vitamin which helps the blood to clot and thus stop continuous bleeding. This fat soluble vitamin is kept in the fat tissue for few days. It is also essential for proper functioning of kidneys and bone growth.