Binding forces

It seems like a magic charm, the word antioxidants. The moment someone is talking about health and food, immediately the term antioxidants pops up. What exactly are antioxidants? And what do they do in our bodies?

To get the answer to these questions, we have to go back to chemistry classes. Let’s start with some basic concepts. Everything – the whole world around us and even we – is made up of atoms. Atoms consist of a core around which a number of electrons is circling. Two or more atoms can bond and together form a molecule. Thus a water molecule consists of two hydrogen atoms and one oxygen atom.

On the outer ring of their electron cloud, atoms prefer an even number of electrons. If they are left with an uneven number, they try to connect with another atom which also has an uneven number. Combined, they end up with even electron numbers in their shared outer rings.

Water molecule (© iQoncept – Fotolia.com)

Water molecule (© iQoncept – Fotolia.com)

Hydrogen atoms indeed are short of one electron. Oxygen atoms do have an even number of electrons. When two hydrogen atoms bond with an oxygen atom they both receive one electron of the oxygen atom. This way the oxygen atom still has an even number of electrons and the two hydrogen atoms also end up with an even number of electrons. Together they form a balanced entity. This results in a water molecule.

Hijack
This process goes very harmoniously until competitors appear on the horizon. These competitors are called radicals. Radicals are unstable atoms or molecules. They have an electron to spare. They would love to bond with other atoms or molecules to receive another electron to make the desired pair and end up with an even number of electrons. They sort of hijack electrons from other atoms or molecules and in doing so can damage the cells of which these molecules are part.

Radicals thus damage walls of cells, called membranes, due to which the cell dies. Their action may also result in destroying proteins and DNA molecules that contain our hereditary information. This starts a damaging chain reaction which may lead to all kinds of diseases.

Early life on earth wasn't able to live with oxygen. Now, we cannot live without it. (© kawin302 – Fotolia.com)

Early life on earth wasn’t able to live with oxygen. Now, we cannot live without it. (© kawin302 – Fotolia.com)

How do radicals form? Oxygen plays a part in this process. You wouldn’t think it, since we cannot live without oxygen, but oxygen actually is a very toxic chemical. When earth came into being, no oxygen was available. The bacteria that populated earth in those times, didn’t need oxygen. In fact, oxygen would kill them.

This lasted until a certain microbe began making use of the abundant amount of water on our planet. These microbes sucked up water, absorbed the hydrogen in it, and secreted the oxygen of the water molecules as waste. Slowly, but steadily more and more oxygen ended up in earth’s atmosphere. For the other organisms living on earth it was a matter of having to like it or lumping it. Or they learned how to use oxygen or they would become extinct.

So, we are descendants of organisms that have succeeded in adaptation during evolution. And now, we are not able to live without oxygen anymore. In our blood, our white corpuscles, part of our immune system, even use oxygen to kill intruders, like unhealthy bacteria.

Reactive
But even for us, too much oxygen is still bad. And many things break down because of oxygen. Butter, for instance, turns rancid due to oxygen, wine turns acid, and iron gets rusty. This is caused by the fact that oxygen is extremely reactive. The element is constantly on the look-out for other atoms and molecules to bind with. This changes the bonds these molecules originally were involved in. And then, for example, iron changes in rust.

Also within our body, similar processes are continuously going on. Molecules that contain oxygen, are losing oxygen atoms during normal metabolism. These oxygen atoms become free radicals. They contain an unpaired electron, which reacts with electrons from neighbouring molecules. This process is called oxidation and damages the molecule involved. Numerous other radicals exist, but in human beings these oxygen radicals are the most numerous.

Oxygen atoms can do a lot of damage, like making iron rust.( © Franxuc – Fotolia.com)

Oxygen atoms can do a lot of damage, like making iron rust. (© Franxuc – Fotolia.com)

Radicals are not only damaging, but have very useful tasks as well. Few of those have been discovered so far. We know, for instance, that these radicals are important to communication between cells and appear to be involved in certain defence mechanisms of cells.

It is certain that we cannot survive without radicals. That’s why, during evolution, certain protective mechanisms came into being to repair damaged cells and limit the damaging influence of radicals. And that is where the antioxidants appear on the stage.

Harmless
Antioxidants have the ability to stabilise free radicals. They form a bond with the free radicals which will render them harmless. An antioxidant can do that without becoming a radical itself and will stay stable. This way, a possibly damaging chain reaction is brought to a halt.

Problems may arise when there are so many radicals that the antioxidants aren’t up to their job anymore. That is when so-called oxidative stress will occur. The free radicals are just roaming about causing damage to cells. Radicals causing oxidative stress are involved in a very extensive range of diseases, among which cancer, Parkinson disease, schizophrenia, bipolar disorder, cardiovascular disease, chronic fatigue syndrome, and Alzheimer disease. And they probably also play a part in the ageing process, when the antioxidants’ line of defence is no longer a match for the continuous stream of radicals.

Supplements
Reason enough to make sure the amount of antioxidants in your body is up to standard.

No positive effect of supplements containing antioxidants has been shown yet. (© Loella Folsom – Fotolia.com)

No positive effect of supplements containing antioxidants has been shown yet. (© Loella Folsom – Fotolia.com)

As a rule, it is not very helpful to take antioxidants in supplement form. A positive effect of supplements containing antioxidants hasn’t been shown yet. Most of the times, they don’t reach the places where they are needed and sometimes, they even exert a negative influence. Vitamin C as antioxidant in pill form for instance generally stays in the bloodstream and in the extracellular fluid. Besides, an overdose of vitamin C on the contrary can cause damage instead of rendering radicals harmless.

Another example is the antioxidant beta-carotene which among other things gives carrots their orange colour. This antioxidant is unsuitable as a dietary supplement. Research showed that people who smoke and take a beta-carotene supplement have a far bigger chance to get lung cancer than smokers who do not take the supplement. Obviously, it is a far better idea to eat a real carrot from time to time!

Food
One of the ways in which we get a lot of radicals in our body, is by eating food rich in saturated fats, for instance fried foods. Using extra virgin olive oil in preparing your meals is a healthy alternative to other, more damaging oils.

The best way to come by the necessary amount of antioxidants is by eating a variety of vegetables and fruits. (© Kurhan – Fotolia.com)

The best way to come by the necessary amount of antioxidants is by eating a variety of vegetables and fruits. (© Kurhan – Fotolia.com)

Diets rich in antioxidants may lower age-related cognitive decline and the risk of developing neurodegenerative diseases. Essentially, all fruits and vegetables hold antioxidants. Very good sources are apples and blueberries. This goes also for broccoli, spinach, potatoes, oranges, and radish. Celery and green peppers contain the substance luteolin, also an antioxidant and good at fighting infections in the brain. Much attention has been given lately to the positive role of dark chocolate that is also rich in antioxidants. This goes only true for dark chocolate containing a high percentage of cocoa, preferably above eighty percent.

It is obvious, the best way to come by the necessary amount of antioxidants is by eating a variety of colourful, cruciferous, and leafy green vegetables and fruits. The required balance between antioxidants and radicals will be created as a matter of course.

Image

Sky diving © germanskydive110 – Fotolia.com
Oxygen atom © OneO2 – Fotolia.com

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