How Antioxidants Fight Free Radicals in the Human Body

In this article, I will be explaining to you what are antioxidants, and how antioxidants work in the human body.

First you need to know what an antioxidant is.

So in general, an anti-oxidant is any substance that inhibits oxidation. For this reason, anti-oxidants have multiple uses, from preventing the deterioration of food products (that’s why people in the middle ages used spices to increase the shelf-life of foods) to preventing free radicals from damaging cells in the body.

Simply put, when your body metabolises chemicals it occasionally produces substances called “radicals”. The simplest and most common form of radical is the free oxygen radical, which is a single oxygen atom unbounded to anything. However compounds can also act as radicals. These radicals are really problematic, because they’re extremely reactive. They’re oxidisers, which means they induce oxidation reactions, and because they’re so strongly oxidising they can force these reactions to occur even on quite unreactive compounds, like proteins or DNA.

When this happens, the protein or DNA becomes misshapen and stops working, which is why peroxide kills things – peroxides are all extremely strong oxidising agents, and oxidise the cells of living things, killing them. Antioxidants then are used by the body to “clean up” most of these free radicals before they can cause too much damage, and they do this through a process called preferential bonding.

Preferential bonding is when a chemical is much more likely to bond to another chemical in the system than anything else, and it can be good or it can be bad. Antioxidants (the most abundant in your body is ascorbic acid, vitamin c) are much more attractive to oxygen atoms than boring old proteins, so the radicals will attach to the acids which will then be cleaned and recycled. They’re kind of like ablative Armour for your organelles, taking the damage and then falling off, only to be recycled and replaced.

Bad cases of preferential bonding includes carbon monoxide, which is much more strongly attracted to haemoglobin than oxygen is. Carbon monoxide chokes you to death because in the presence of both oxygen and CO, your haemoglobin (which is the protein responsible for carrying oxygen) will bond to the CO first. However, the CO is so reactive that you can’t easily get it off, so it just builds up and up and up and eventually none of your red blood cells are carrying oxygen to your cells, and you die.

Note that free radicals aren’t always bad. For example, a safe amount of free radicals stimulate the immune system to increase its defense against free radicals. Free radicals are also used by white blood cells, called “defender cells”, to blast and kill invading foreign pathogenic cells. So free radicals are also a part of our immune system’s defense.

Random Facts About Antioxidants

There is a ton of research I need to do about antioxidants, but instead of throwing away the interesting scraps of information, I guess I’ll just list them right here:

  • When all other antioxidants in the body have been used up, uric acid is used as “the last line of defense”, or the fall back antioxidant. So if you get checkup at a clinic and find that you have low uric acid levels, then perhaps there is something wrong going on in your body? It’s not a good sign if your body is low on antioxidants to resort to uric acid (not that uric acid is bad, but being low on antioxidants is).
  • Whereas the body’s first line of defense, in terms of antioxidants, is glutathione.

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