Food & Fitness

The role of oxidants and antioxidants in health

I am delighted to share this guest post with you all, written by the boyfriend! He has a background in biology and geography and is excellent at understanding and explaining science. Today he’s written this article to give us some information of exactly what’s going on with free radicals and antioxidants and what they mean in the food that we eat. Next week, I’ll follow-up his article with advice for how you can apply this information to your diet! Be sure to come back on Monday to read about foods rich in antioxidants.

Oxidants and anti-oxidants are a common topic in health and wellbeing discussions, but what do they mean exactly? From a chemistry perspective, an oxidant is an atom or molecule that takes electrons from another atom or molecule. An antioxidant is a molecule that donates or shares an electron with the oxidant, preventing the removal of electrons from critical cellular molecules.

The current atomic model in chemistry visualizes discrete shells that electrons inhabit, each shell having the capacity to receive a limited number of electrons. Only the outermost shell of an atom is involved in the interactions between atoms.

For example, water (H2O) is composed of 2 hydrogen atoms and 1 oxygen atom:


Each hydrogen has an unpaired electron in the outer shell and each oxygen has 2 unpaired electrons. The interaction between these 3 atoms causes the outer electron shells of all three to become filled leading to higher stability and less interaction with other atoms.

So what does this mean from a health perspective?

Oxygen has a very high electron affinity (second only to Fluorine) and it will fill its electron shell from any atom or molecule that has a weaker electron affinity. A common cellular function of oxygen is to act as a terminal electron acceptor in the process that produces adenosine tri-phosphate (ATP) in organelles termed mitochondria. ATP is the energy of cells and is composed of adenine (amino acid), ribose (sugar), with three phosphorus atoms attached, as shown below:


If oxygen exits this process with a partially filled electron shell it becomes an oxidant (free-radical). This free radical will then attempt to take an electron from another molecule, and if successful, will lead to a change in conformation of the molecule and alter its function.

Antioxidants are molecules that remove free radicals from the body, likely by donating an electron to the oxidant, or sharing an electron with the oxidant thus bonding it to the rest of the structure, both of which would make the oxidant inert:


Free-radicals attack the cells in the body, so we need to consume foods rich in antioxidants to halt free-radical damage. Check back next week for Part Two: foods rich in antioxidants!

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    1. The Boyfriend / Mr Science

      First off, how about Captain Science? Maybe Captain Science McAwesomeville? 🙂 Anyways, in brief, if an electron is removed from a molecule (an integral protein imbedded in the plasma membrane is an example), the altered structure results in altered function resulting in decreased efficacy of that particular cell. I expect the protein (in this example) could be repaired or replaced, but this requires energy and resources. If you have a plethora of free radicals careening through your body, these repairs could significantly deplete your body’s resources. I still want to look into the claim (particularly by ASEA) that antioxidants must first be activated in order to interact with oxidants.

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  3. astaxanthin benefits

    Antioxidants plays a very important role in keeping our skin and overall health healthy. If you want your skin to look healthier and younger, it is best to consume foods that are rich in antioxidant power. Also, with regular exercise and atying away from bad habits like alcohol and smoking, you can have a healthier looking skin.

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