Updated 02 June 2014

Antioxidants: the key to health

You've heard about them, but just what do antioxidants do, and why do we need them? Here are the answers to 12 questions on antioxidants.


You've heard about them, but just what do antioxidants do, and why do we need them? Here are the answers to 12 questions on antioxidants.

What are antioxidants?
Exactly what the name suggests: against oxygen. Every living thing needs oxygen, but certain chemical forms of oxygen can be detrimental to our health. In these dangerous forms, they are called free radicals. Antioxidants donate electrons to free radicals to neutralise them.

What does the term "abnormal" oxygen mean?
Abnormal oxygen molecules are formed in the body during all metabolic processes. A normal oxygen atom has two pairs of electrons (negatively charged energy fields) revolving around the nucleus (centre of atom). This means the oxygen atom is in balance.

During the metabolic processes an extra electron may attach itself to the oxygen atom, making it unstable and biochemically active. Now it's a free radical, and wants to pass on the extra electron to its nearest neighbour, or remove an electron from its neighbour to restore a natural balance. This, in turn, will cause the neighbour to become a free radical. This chain reaction can wreak havoc in a cell.

Why are free radicals a problem?
Free radicals accumulate in the cell membrane, eventually causing it to break, and the cell content to leak out, rendering the cell useless. It can also damage the cell nucleus containing the sensitive DNA molecule which controls all cell functions.

Free radicals can also destroy enzyme systems and damage mitochondria (the power stations in each cell responsible for energy production).

Most free radicals are formed in one of four ways:

  • They are manufactured during the production of cell energy, where they are the byproducts of the metabolic chain.
  • The detoxification and neutralising of foreign substances such as medication, alcohol, toxins and chemicals generate free radicals.
  • When the immune system is activated to eliminate or neutralise foreign organisms (bacteria, parasites and fungi), abnormal cells (such as cancer cells) and foreign protein molecules (such as found in cow’s milk or other food substances to which some people are allergic), the white blood cells manufacture free radicals to attack these invaders. The excess free radicals remain following the attack.
  • Free radicals also penetrate the body from the outside, from sources such as ultraviolet light, air pollution, insecticides, poor diet and medication.

If free radicals damage the DNA growth control centre, cells can lose the ability to know when they should stop dividing and growing. They can also lose their ability to differentiate, and will no longer 'remember' what kind of cell they are.

The DNA of every healthy cell contains the memory of the function of every other cell in the body. If the codes become confused, a liver cell could suddenly start growing uncontrollably, and develop into a muscle cell where there should not be any muscle cells. This is what happens in many types of cancer.

Cells grow uncontrollably and without differentiation in what amounts to a suicidal frenzy. The cancer cells eventually destroy the total functioning of an organ, even destroying themselves in the process.

Why is it important to neutralise free radicals in the brain?
The brain is particularly sensitive to free radical damage in the phospholipid membranes of the nerve cells.

Herbs such as ginkgo biloba and the plant nutrient pycnogenol, found in grape seeds and pine bark, have the ability to penetrate the blood-brain barrier. The antioxidants in them are then able to neutralise the free radicals inside the brain to prevent damage to the nerve cell membranes.

The damage caused by free radicals has more impact on the deterioration of the intellectual functions in Alzheimer's disease and senile dementia than the degeneration of the nerve tissue as such.

How does the body protect itself from free radical damage?
There are three antioxidant enzymes in every cell of the body that keep free radicals under control. They are superoxide dismutase, catalase and glutathione peroxidase. These enzymes donate an electron to the hyperactive oxygen and hydrogen radicals, which are then neutralised and rendered harmless.

If the body makes its own antioxidant enzymes, why do I need to take them in the form of food or supplements?

The enzymes cannot always cope with all the free radicals that are formed because:

  • The ageing process exerts increasing demands on the enzymes, and the enzymes become less active. Ageing is the sum total of the damage caused by free radicals over a lifetime. It is never too late to take antioxidant supplements, but if you wish to slow down the ageing process, the sooner you start, the better. Attitude and general lifestyle also play a major role in the ageing process.

  • Increased production of free radicals (more free radicals are produced than the three enzymes can handle). This often happens to people who participate in sports competitively - the more active and competitive they are, the more free radicals are formed on account of the increased metabolism. Active sportsmen and women should therefore take antioxidant supplements to cope with the increased production of free radicals. This would improve their performance and increase their endurance - the damage caused by free radicals is reduced and the immune system is boosted, which means fewer infections.

  • People who suffer from diabetes have an abnormal glucose metabolism combined with oxidative stress (which increases oxidation - thereby increasing the production of free radicals). Supplementary antioxidants restrict the tissue damage associated with diabetes, reduce the need for insulin and limit the eventual damage to the end organs (kidney damage, nerve damage, eye damage and gangrene) so often linked with the disease.

  • All forms of chronic disease (such as arthritis, chronic fatigue, chronic infections, emphysema, multiple sclerosis, Alzheimer's, atherosclerosis, high cholesterol, varicose veins, cancer and AIDS) result in an increased production of free radicals, which spreads the damage caused by the disease and aggravates and prolongs the disease.

  • Prolonged or uncontrolled stress over a long period can significantly increase the metabolism. The enzymes responsible for maintaining the stress metabolism work harder and the free radicals increase significantly.

  • Increased exposure to free radicals from the environment such as cigarette smoke (inhaled directly or indirectly) and industrial smoke from factories and fires; air pollution caused by factories, vehicle exhaust fumes and heaters and exposure to ultraviolet light, including excessive exposure to sunlight.

  • In genetically susceptible people, exposure to carcinogens (substances that cause cancer).

The immune system is an extremely active system. The enzymes work at top speed to protect you against pollution, carcinogens, viruses, bacteria, fungi and every foreign invader imaginable. The lifestyle we lead today puts a high demand on the immune system. Without antioxidants, we will suffer the consequences.

What are some examples of antioxidants?
The prominent ones are beta carotene (and the other carotenes or carotenoids), vitamins A, E and C, and selenium, zinc, copper and manganese. Others include pycnogenol (found in pine bark and grape seed extract), co-enzyme Q10 (essential in the mitochondria or power generators of our cells), lycopene (in tomatoes), and phytonutrients in cruciferous vegetables, bioflavonoids, cat's claw, alpha lipoic acid and glutathione.

All fresh fruit and vegetables are sources of antioxidants and other phytonutrients (plant nutrients).

What are the other functions of antioxidants in the body?

  • They support the systems of people who have to undergo chemotherapy or radiotherapy for cancer. The therapy causes a considerable increase in free radical formation and it suppresses immune function as it kills off all fast-growing cells.
    This includes the cells responsible for hair growth and in the digestive tract. This is why people who undergo these treatments suffer from so many side effects. Every person who is undergoing any form of cancer treatment should take supplements. There are no contraindications – in fact, the therapy will be more effective.
  • They prevent the oxidation of LDL-cholesterol, which must happen before LDL-cholesterol can penetrate the walls of the blood vessels to start the process of atherosclerosis (thickening of the arteries).

  • In the absence of reliable food sources, antioxidant supplements form an integral part of the biochemical structure of the body's own antioxidant enzymes. Glutathione peroxidase (GP) increases the concentration of vitamin E; selenium is an essential co-factor of glutathione peroxidase; and copper, manganese and zinc are part of the structure of superoxide dismutase.
  • Antioxidants have the ability to cause cancer cells to return to normal by restoring the growth control function of cells in the DNA molecule of the cell nucleus.

Should I take all the antioxidants available, or just one or two?
Antioxidants are linked, and work best in synergy. Each has a specific function, and needs the support of most of the others.

Ideally, they should be taken in the form of fresh fruit and vegetables – that's five to nine portions a day, which few of us manage. Still look out for things such as raw honey, certain algae (like spirulina and blue-green algae) and whole red grapes (skin and pips), as these contain most of the antioxidants and other micronutrients. However, because quantities are small, it is advisable to supplement with a broad spectrum antioxidant.

People who have cancer or any other chronic disease should take twice the recommended dosage. If you can divide your daily intake throughout the day, it is better than taking it all at once.

When choosing a supplement, the quantity of each individual ingredient is less important than finding a combination that contains many antioxidants from a variety of plants (herbs, fruit, vegetables) in one product.

When would you recommend grape seed extract?
Since pycnogenol is able to penetrate the blood-brain-barrier to neutralise free radicals inside the brain, it's a good one to take after a stroke or to help Alzheimer’s patients. It reinforces the capillaries and blood vessels – an important function after a stroke.

Also, as a potent free radical scavenger, it supports the immune system in cancer patients and for autoimmune diseases.

Pycnogenol is also important in the treatment of arthritis and disorders involving poor blood circulation such as diabetes, varicose veins and cardiovascular problems. I recommend you look for a supplement that has pycnogenol from grape seed or pine bark, but that also contains other antioxidants to ensure a comprehensive supplement.

What are the best antioxidants to take in supplement form?
Choose from the following list, and take one or two products (one to four tablets) a day. Look for products that contain as many of the antioxidants as possible and ensure that you do not have to take eight tablets a day to get enough of everything. N-acetyl-L-cystein can be taken as a separate supplement.

  • Beta and mixed carotenes (15 - 25mg) with vitamin A (2500 - 5 000 IU / 750 – 1500 microgram RE)

  • Vitamin E and selenium (100 - 200 IU or 83 - 166 mg of vitamin E and 100 - 200 micrograms of selenium a day)

  • Vitamin C (1000 - 2 000 mg)

  • Minerals: zinc, copper and manganese (Zinc 15 mg, copper 2mg and manganese 10mg a day)

  • Vitamin B-complex (25 - 100 mg plus 400 microgram folic acid and 50 microgram B12). The B-complex group of vitamins acts as minor antioxidants. As cofactors, however, they are essential for the effective functioning of the antioxidant enzymes.

Folic acid is essential for normal deoxyribonucleic acid (DNA) in the nucleus of every cell. Marginal deficiencies can lead to chromosome defects. Most adults have a folic acid deficiency, making supplementation essential. This is especially important in cancer where a malfunction in growth control caused by a genetically inherited DNA chromosome abnormality already exists.

Vitamin B 12 and folic acid reverse early changes in lung cancer. Vitamin B6, B12 and folic acid are also very important for regulating the quantities of homocysteine (raised levels can lead to heart disease).

  • Co-enzyme Q10 (10 - 20 mg twice a day)

  • Cruciferous and carotenoid complexes. Several antioxidant combinations contain extracts of broccoli, cabbage, mustard seed, acerola cherries, cauliflower, tomato, carrot, celery, turmeric and rosemary.

  • Bioflavonoids – flavonoids are water-soluble phytochemicals which impart the pigment to fruit, vegetables, cereals, seeds, leaves and tree bark.

  • Alpha lipoic acid (ALA) (20 - 100 micrograms a day) - a potent antioxidant that delays and retards the onset of the ageing process. ALA is also commonly used in the treatment of diabetes and to support the liver's detoxification ability. It is effective in neutralising toxic metals, medication and other metabolites. Spinach, liver, red meat and broccoli are excellent sources of ALA.

  • Ginkgo biloba (120 - 160 mg a day in divided doses).

  • The amino acids L-cysteine (500 mg a day) and N-acetyl-L-cystein (500 mg a day on an empty stomach) are both part of the protein glutathione and both act as very potent neutralisers and scavengers of free radicals on their own. Together with glutathione and selenium, they form the extremely strong enzyme glutathione peroxidase. L-cysteine (L-cys) and N-acetyl-L-cysteine (NAC) can be taken as separate supplements. They will be converted to glutathione in the body, along with selenium.

  • Vitamin C and B6 should also be taken with all amino acids. Unlike vitamins, amino acids are absorbed best when taken on an empty stomach.

Green and black teas contain catechins which provide protection against LDL-cholesterol oxidation and suppress the growth of many types of cancer. They also provide protection from the damage of free radicals caused by air pollution and smoking.

Soy beans contain isoflavones such as genistein and daidzein. These bioflavonoids have weak oestrogen activity and protect against oestrogen-dependent cancer (breast cancer and cancer of the uterus) and prostate cancer by binding to cell receptors and preventing the body's potentially cancer-forming oestrogen from binding to them.

Isoflavones are also recommended for treating symptoms of menopause, heart disease and osteoporosis.

The onion family, including red onions, garlic, shallots and leeks contain flavonoids such as quercetin, vitamin C, selenium and sulphurous substances. Garlic provides protection against free radicals, prevents LDL-oxidation, provides protection against cancer and is used in the treatment and prevention of all types of infections. It improves immunity and reduces blood pressure. It acts as an expectorant (loosens phlegm) in respiratory tract infections. Garlic reduces fever and also acts as an antiseptic.

Red onions are rich in quercetin, a bioflavonoid which acts as an expectorant in infections of the upper respiratory tract. Onions reduce blood pressure and cholesterol and prevent the formation of blood clots (in thrombosis, heart attacks and stroke). They also help to fight cancer.

What is a good combination for someone with heart disease and high cholesterol?
The recommended dosage and combination for those suffering from cardiovascular disease or high cholesterol with atherosclerosis: Vitamin E (400 IU or 332mg,) B6 (50 mg) and B12 (50 microgram), including folic acid (400 microgram) are the most important. They are inexpensive and easy to take. These are extremely effective in preventing the accumulation of homocysteine, one of the most important risk factors for heart disease.

Apparently grapefruit seed extract has a similar effect to antibiotics and 10 drops two or three times a day can help a bacterial, fungal or parasitical infection. Do you agree?
Research has shown that grapefruit seed extract (rich in citrus bioflavonoids) is effective against some intestinal pathogens (disease causing organisms) such as Candida albicans and other Candida species (fungi), some Eschericia coli (bacteria) species and with a slight effect on Staphylococcus aureus (bacteria).

It has shown no side effects (except for the bitter taste!) and the normal bowel flora stay unaffected. It is effective as part of the natural treatment of constipation, flatulence and abdominal discomfort, as well as for bladder infections, thrush and vaginal candida infection.

(Dr Arien van der Merwe, Health24)

Read more:
10 sources of antioxidants
Antioxidants under fire


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