Saturday, December 4, 2010

Weekly article: Antioxidants help slow down the ‘rusting’ of the human body

AN apple turns brown or a nail gets rusty due to oxidation. The same process occurs within us. We do not change colour or become rusty, but the tell tale signs come later as “wear and tear” in ageing, poor health, or chronic diseases.
We often blame our genes for our maladies, but environmental factors and lifestyle choices account for as much as 70% for the apple inside us turning brown too fast, too soon.
If we smear some lemon juice on a cut half of an apple, the browning process is retarded as the lemon slows down the oxidation process, hence conferring an antioxidant effect to the apple.
As we are more complex than an apple, smearing ourselves with lemon just would not work!
Antioxidants were first applied in industrial use two centuries ago to protect materials such as rubber from degradation, and was later introduced to preserve certain foods and oils to extend shelf life.
It was only 60 years ago that its significance in human physiology was recognised.
But doctors were so busy battling diseases that, until recently, the protective role of antioxidants has not been fully appreciated.
To be honest, yours truly had no idea what they really were. My only knowledge of antioxidants was restricted to oranges and wine. I thought “free radicals” was a new political party!
We now know that they are the culprits in causing oxidation within us, and antioxidants neutralise them.
The word antioxidants conjures much excitement and sometimes emotions as there are many claims and counter claims. Earlier studies showed great promise on health, later ones disputed that, and on it goes like a yo-yo. The subject is extremely confusing and this discussion tries to put them into separate baskets for ease of mental digestion.
There is a plethora of antioxidants in our foods, chiefly found in fruits and vegetables: the more coloured and pigmented, the richer it is in antioxidant content.
Variety is the key to good health and the more the merrier. The American Cancer Society recommends at least five servings of fruits and vegetables per day to prevent cancer. Trying to keep the doctor away by having an apple a day is a myth ... it is not enough! One can try five, and that still would not be enough.
To illustrate: the level of vitamin E known to effectively combat oxidative stress is 400IU. If one eats spinach only or has a girlfriend called Olive, the poor fellow has to consume 12.7kg of the vegetable to get the optimal level of vitamin E.
Apart from indigestion, Popeye probably has staghorn kidney stones, considering the amount of oxalates found in spinach.
Unlike Homo sapiens, antioxidants work in a synergistic fashion. Each is like an instrument in a philharmonic orchestra, playing the right note, at the right pitch and tempo, and supporting the other performers elegantly. The flawless symphony within is the key to anti-ageing and prevention of chronic diseases.
Some are water-soluble and work only in fluid compartments; some are fat-soluble, protecting the lipids in cell membranes. Some work outside the cells, and some only within.
The brain is a private club allowing entry only to members of valued standing. Among the select antioxidants that has an entry ticket is vitamin C and a family of powerful protectors known as OPC (oligomeric proanthocyanidins, found in grapeseed extract). Together they form a duet in quelling free radicals in the headquarters of our very existence.
As much has been unraveled about the role of antitoxidants, it is now no longer relegated to the cloakroom of science or the twilight zone of alternative medicine. It is only the naive or the incalcitrant mind that rejects its significance. We were already endowed with it when man first walked the earth, and he had the foresight to eat apples as an additional booster, as ancient script goes.
The dreaded free radical that brings forth harm is known as “superoxide”, an unstable oxygen molecule, resulting from churning up energy in the body. To render this harmless, our cells possess an antioxidant enzyme called superoxide dismutase. Together with catalase and glutathione peroxidase, they complete the job of snuffing out the smoke, thereby preventing the free radicals from wantonly zapping our cells.

On top of this, our body also produces co-enzyme Q10, which is an in-house antioxidant in the power plant (mitochondria) within our cells. It recruits a helper in the form of alpha-lipoic acid to clean up the mess.
Did you know that uric acid is also an antioxidant? This is not a reason to gobble down pots of meat – bone tea (literal hokkien translation) in excess will cause a pretty painful joint, or worse, excruciating back pain with blood in the urine due to kidney stones.
The moral of the story: do not raise the level of the wrong antioxidant. Not all things natural are always good.
Primary antioxidants
Early research centred around vitamins A, C and E, which are collectively known as primary antioxidants. They are called essential nutrients because the human body cannot do without them. Since we cannot manufacture vitamins, they must be derived from the diet.
The plant form of vitamin A is called beta-carotene (a pro vitamin), found in carrots, papaya, berries, pumpkins, etc. The body converts this precursor to vitamin A as and when it is needed. However, too much intake will cause harmless discolouration of the palms. Both vitamins A and E are fat-soluble, thus preventing the oxidation of lipids within the cell membrane.
On the other hand, vitamin C is water-soluble and mops up the free radical burden from the blood.
Supporting antioxidants
Under this category are the “others”. They are not absolutely a must, but do a whole lot of good if they are available. The bioflavanoids, carotenoids, and polyphenols are essentially derived from plants and are collectively called phytonutrients. The number of compounds within these groups is mind boggling and only a few are highlighted for enlightenment.
OPC (oligomeric proanthocyanidins), found in seeds of the red grape (commercially as grape seed extract), is a potent antioxidant, aiding in the ridding of free radicals both in the water and fat compartments of the body.
Isoflavones derived from soy offers itself as a weak oestrogen, and relieves menopausal symptoms.
Lycopene is found in tomatoes but enriched when pureed. It has been found to reduce the risk of bladder cancer.
Lutein, found in dark green leafy vegetables, protect the eyes and slow down the onset and progression of a chronic eye disease (macular degeneration).
Quercetin is derived from fruits, grains, and vegetables.
Catechins found in tea is an excellent antioxidant.
The list is exhaustive and includes gingko biloba, zexanthine, hesperidin, etc.
The quintet: Five good friends form an antioxidant network, namely vitamin C, vitamin E, glutathione, alpha-lipoic acid, and finally CoQ10. They support each other by interactive regeneration. When vitamin C has done its job, instead of being discarded, it is reactivated by vitamin E. Gluthathione regenerates vitamin E. Alpha-lipoic acid recycles coenzyme Q10. Together, this five-piece quintet harmoniously delivers a masterpiece.
The antioxidant minerals: These are not themselves antioxidants but help to replenish the endogenous antioxidant status. Selenium (found in shell-fish, eggs, chicken, garlic, etc) is needed to build up the level of glutatione. Manganese, copper, and zinc are trace minerals which help to boost up the level of superoxide dismutase.
Science is only beginning to unravel the many intricate mysteries within us, so there will necessarily be debates as illustrated by the many conflicting views that is beyond the scope of this discussion.
Suffice to point out that applying drug study models and expecting each antioxidant to work independently like a pharmacological agent in sick patients is illogical and often produces the contradictory results that we rant about. Antioxidants are not drugs and are part of the body’s defence and healing system. Until there is a full appraisal of this wondrous orchestra without leaving out a single instrument, we may never hear the true music.
We can view antioxidants in three concentric rings. Replenishing the inner circle of natural antioxidants takes centre stage, followed by the middle circle of primary antioxidants, and finally giving the outer circle (“the others” supporting antioxidants) its deserved attention.
Most people rave about a new discovery in “the others” category as the next magic bullet, and we have all seen quite a few of these. Incidentally, selenium created a wave of interest in 2002, following a study that revealed that men taking 200ug of the mineral a day seem to have lower incidence of prostate and colon cancer.
A sales representative tried to promote the supplement two years later and asked if I had heard about this study. I can remember the incredulous look on his face when I said “No”. I almost chased him out of my room. Thinking aloud then, I wondered how this guy had the guts to sell a nutritional supplement to a doctor.
Today, if I ever have the opportunity to meet him again, I would apologise and thank him. To many of my friends, I have this advice – do not let naivety and scepticism cheat you of good health.
Being both naive and sceptical, I paid the full fare for my folly. Fortunately, not too long ago, I heard the beautiful symphony of the antioxidants and I now share the notes with you. If our car needs anti-rust, so do we!

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