Antioxidants burst onto the health scene many years ago. Since then, you can find all kinds of products claiming to be full of them, from skincare to smoothies. But what are antioxidants in the first place? What do antioxidants do, and do we really need them? We cut through the jargon to get to the truth about these mysterious molecules.February 05, 2021 1:54 pm February 01, 2021 4:20 pm
What are antioxidants?
Let’s start with the basics.
The word ‘antioxidant’ represents a whole range of different substances. Many are natural, although some can also be manmade; we even produce some antioxidants naturally in our bodies.
Vitamins A, C and E are all antioxidants.
To be classed as an antioxidant, the substance must be able to help prevent a process called ‘oxidation’.
Oxidation, which we’ll talk about in more depth below, is a process which can damage your cells. It’s happening almost continually in your body.
In effect, antioxidants help to protect your cells and keep them healthy. This in turn presents an enormous range of possible health benefits, including protection from some illnesses.
It makes sense: when your cells are healthy, they’re better able to perform their normal function and less prone to disease.
But what causes oxidation in the first place?
What are free radicals?
Like the term ‘antioxidants’, the term ‘free radicals’ also applies to many different substances. To be classed as a free radical, the substance must:
- Be able to exist on its own
- Have an unpaired electron.
You produce a certain number of free radicals simply due to your cell’s normal metabolic processes.
One of the most common types is called ‘reactive oxygen species’, or ‘ROS’. This simply refers to the fact that this particular type of free radical molecule contains oxygen. If you’re reading up on antioxidants, you’ll probably come across ‘ROS’ now and again!
Now, it’s important to say that, at low levels, free radicals aren’t all bad. In fact, you need them to make certain cellular structures and to fight off germs.
Phagocytes, which are a specific type of germ-fighting white blood cell, even make and store free radicals which they can then use to destroy invading pathogens.(1)
However, when there are too many of them in your cells, free radicals can start to cause damage. This is called oxidative stress.
What is oxidative stress?
To stay healthy, your cell needs to maintain a delicate balance; it has to create free radicals during its normal processes, but it also has to neutralise these before they can cause any damage. The cell neutralises free radicals with antioxidants.
When the two are balanced, your cell can go about its normal business without damaging itself.
However, sometimes the balance can tip in favour of free radicals. There simply aren’t enough antioxidants to neutralise the free radicals, and they start to damage your cells.
A build-up of free radicals can be caused by external factors such as pollution, cigarette smoke, UV light, radiation and certain drugs and pesticides.(1)(2)
How do free radicals cause cell damage?
Prepare yourself, because we’re about to dive into some serious science here (albeit heavily simplified!).
As we know, free radicals are unstable because they are missing an electron.
If, in the hazy distance of the past, you can remember high school physics, you will likely remember that electrons like to exist in pairs.
If you split them up, the atom becomes unstable. It wants to find another electron quickly so it can return to a stable state.
Usually, an antioxidant comes along at this point and donates an electron. The antioxidant is stable enough to do this without destabilising itself (this is sometimes called ‘free radical scavenging’).
The free radical gets its missing electron, becomes a stable molecule again, and everyone goes back to work.
"Scientists believe that oxidative stress is a factor in all kinds of diseases, from inflammatory diseases like arthritis to heart disease and neurological disorders like Alzheimer’s and Parkinson’s diseases.(2)"
Free radicals during oxidative stress
However, during periods of oxidative stress, there is simply no antioxidant to be found. So, the free radical becomes a thief!
It goes in search of other molecules in the cell which it can react with and steals an electron to stabilise itself. Important substances like lipids, proteins and DNA are its targets.
Unfortunately, that leaves the victim molecule without an electron. Now, it must look for another electron itself. This sets off a chain reaction wherein molecules go around stealing electrons from one another.
This goes on until finally a certain type of free radical is produced which can pair up with others of the same type, and the reaction comes to a close.
Unfortunately, the removal and regathering of electrons (called oxidation and reduction in science-speak) causes damage to the molecule. When this happens to the lipids in your cell membranes or to your DNA, you can see why it would cause problems.
Diseases linked to oxidative stress
Damage to important elements of your cells has consequences, and free radicals are linked to quite a few human diseases.
Scientists believe that oxidative stress is a factor in all kinds of diseases, from inflammatory diseases like arthritis to heart disease and neurological disorders like Alzheimer’s and Parkinson’s diseases.(2)
They are thought to play a role in the ageing process, and are also linked with the onset of cancer.(2)
Thus, it’s really important to try and avoid oxidative stress as far as possible.
How can you avoid oxidative stress?
There’s no way to completely avoid oxidative stress; to some extent it’s just a natural process that occurs from time to time.
However, you can take steps to reduce the likelihood of it happening.
One way to do this is to make sure you’re getting a good supply of antioxidants from your diet.
Another way is to avoid the environmental stressors which can increase the amount of free radicals in your system. For example, you should avoid smoking or inhaling someone else’s cigarette smoke, drinking alcohol in excess, and limit your exposure to chemicals and pollutants.
Many scientists have linked a plant-based diet containing lots of fresh fruit and vegetables with a reduced risk of diseases caused by oxidative stress.(3)
Thus, one of the simplest things you can do to protect yourself from oxidative stress is to eat a healthy, balanced diet.
Some foods are particularly high in antioxidants, though, and would make a worthwhile addition to all of our diets.
Unsurprisingly, fruit and vegetables rank highly in terms of their antioxidant content. Berries are a particularly good source of antioxidants. Bilberries and amla (Indian gooseberry) score particularly highly, but more accessible strawberries, blackberries, sea buckthorn, aronia berry and cranberry all provide a good dose.(3)(4)
When it comes to vegetables, artichokes, curly kale and broccoli are good examples,(3) although it’s worth noting most fresh fruit and vegetables will contribute to your antioxidant intake.
Interestingly, many herbs and spices are a great source of antioxidants. Cloves rank the highest, but ginger, mint, cinnamon, thyme and many others are also exceptionally high in antioxidants.(3)
Pleasingly, dark chocolate, red wine and espresso are all high in antioxidants too, although there may be other reasons not to go overboard on these!(3)
Protecting yourself from free radicals
As mentioned, not all free radicals are bad. Nor can you protect yourself completely from damage caused by them.
However, the best thing you can do to keep oxidative stress at bay is to eat a healthy diet. Fill your plate with a wide variety of colourful vegetables and fruits and make sure you’re eating enough whole grains.
Meanwhile, avoid cigarette smoke, excess alcohol and environmental pollutants.
This is not just good advice when it comes to free radicals, but will keep you in general good health as well.
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