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Nutritional Therapy - Antioxidants

Updated: Oct 20, 2020

We hear the word antioxidant branded around - anything from face creams to a cure for cancer, but why? How do they work and why do we need them? Found in coloured vegetables and beverages such as red wine and green tea, they are vital to health. Read on to find out more.

Eat the Rainbow Oxygen, whilst essential to life is also very reactive. This is because the chemical structure of oxygen consists of two unpaired electrons; uncoupled electrons create damage to our cells (a little bit like a bull in a china shop) as they are looking to gain stability. The changes in electrons produce different chemical forms of oxygen and collectively these reactive forms are known as Reactive Oxygen Species (ROS); with some being more detrimental to our health than others. Antioxidants help to keep oxygen in stable forms by either donating or accepting an electron and therefore reduce the amount of wear and tear that our cells are subjected to.

The chemistry part: when oxygen gains an electron it forms a superoxide; a need for a lone electron produces a more reactive molecule and these are very dangerous to our cells. If a second electron is received hydrogen peroxide is formed; this is less harmful to the body as it can be broken down by enzymes in the body. Perhaps the most damaging ROS is made when a superoxide combines with a hydrogen peroxide molecule to form a hydroxy free radical which is short-lived and highly reactive; this ROS can not be broken down by enzymes and therefore antioxidants hold significant value.

Imagine if the amount of ROS produced in your body was greater than the antioxidants consumed? Would it be fair to expect ageing, degeneration and incorrect cellular replication? It is vital to obtain antioxidants from the foods we eat given ROS are a natural by-product of our bodily processes, including digeston. When we convert food into energy, electrons are exchanged for oxygen in cell membranes; around 2% of the oxygen leaks out during this process forming superoxides. Luckily the superoxides can be converted to hydrogen peroxide when given an election from an antioxidant donor; the effectiveness of which relies on ones nutritional status, as you will see further down.

Hydrogen peroxide is a by-product that needs to be well managed in the body as it is needed for many roles such as: cellular communication, immune responses, causing cell death, gene expression and the transportation of ions and blood clotting mechanisms. As an example, if you cut finger the blood platelets produce hydrogen peroxide which acts as a cell communicator, signalling and recruiting additional platelets to the area for wound repair. Quite amazing but with poor nutrition these processes come at a cost to the body - we literally age faster.

And... we haven’t factored in the stressors that occur due to our external environment. Some of us, depending on our lifestyle, need more antioxidants than others. In plants, ROS species are produced in response to stress. Human stressors within the environment include pollutants, heavy metals, ionising radiation, cigarette smoke, heat exposure, vaccinations, pesticides, chemicals and pharmaceuticals which create additional damaging radicals. So, you see, it is important to stock up on the good - especially in a toxic world. A plant-based diet can help to provide these vital antioxidants; aiming for at least 8 -12 portions of fruits and vegetables.

Aren't recommendations to eat five portions a day though? Maybe so but studies have shown foods grown in the 1940’s were at least 40% - 60% more nutritious than they are in the present day creating an increased need. But why? Well, simply, our farming practices are ruining our health and food quality. The vegetables we eat have been cut and packaged long before they hit the shelves, usually having been imported and dehydrated during travel reducing freshness and antioxidant power. Most vegetables are intensively farmed in soil devoid of nutrients, with fertilisers that support growth rather than a balanced nutrient status as well as additional pesticides. It is perhaps easy to see how our food quality has declined. In the past soil had a varied microbiome creating more nutritionally dense foodstuffs, most often produced locally and seasonally, providing fresher choices with an array of antioxidants, rather than relying on the same foods day in day out.

Essentially, for many reasons, we need to be eating far more nutritious foods to obtain the nutrients we need to remain vital. If radicals are not managed correctly or outnumber the protective antioxidants we consume then oxidative stress can occur. Oxidative stress is implicated in a variety of inflammatory dis-eases and degenerative disorders including: cancer, Alzheimers, macular degeneration, Parkinson's, cardiovascular disease and essentially the phenomena behind the ageing process!

Read on to learn what an antioxidant is and how they work. Whilst reading consider the complex interactions require a VARIETY of nutrients and how they all work in synchronicity. I like to think of nutrition as a game of mouse trap, the whole mechanisms fails when one part is missing.Nutrition is similar; a deficiency somewhere in the chain causing significant impact on our whole system, often with devastating effects long term.

Antioxidants work to control ROS levels by scavenging or detoxifying ROS. There are different types of antioxidants - non-enzymatic antioxidants and enzymatic antioxidants. Whilst these names sound complex, enzymes are simply catalysts which cause a specific reaction in a particular substrate; something like a lock and key. Whilst the names seem complex all enzymes have the suffix of -ase. Enzymatic antioxidants are considered as our first line of defence and include Superoxide Dimutase which breaks down superoxides and then Gluathione Perioxidase and Catalase which break down hydrogen peroxide - a two-step process.

Glutathione Perioxidase contains selenium, glyceine, cystenine and glutamate with the three latter components coming from the proteins we eat. It is the master intracellular antioxidant which protects cells from injury; it works to protect cell membranes, our skin linings, stops fats oxidising (such as cholesterol) and negates the effects of pollution. We have many more enzymes but this is just one example; different enzymes require a different metal to work, either zinc, manganese, copper or iron, allowing the enzymes to change their oxidative states (able to donate an electron). To do this however, these vital enzymes require a variety of nutrients which act as co-factors including: selenium, B vitamins and sulphur which work in synergy and act as electron donors. You can see without all of these important co-factors ROS are going to reign supreme.

Non-enzymatic antioxidants include: vitamin C, vitamin E, beta-carotene (plant form of vitamin A) plus others compounds such as polyphenols (found in wine, for example) which we obtain from the foods we eat. These small molecules work on the most dangerous hydroxyl radicals, terminating chain reaction by donating electrons to produce stable molecules and stop damage.

Water based antioxidants act within our fluid environment both inside and outside the cell. Fat soluble antioxidants work to keep our fatty cell membranes healthy; together with enzyme based antioxidants they provide a wondrous protection system! We will now take a look in more detail on some specific antioxidants.

Vitamin E - is a fat soluble antioxidant which supports the integrity of tissues and cell membranes, including red blood cells and low density lipoproteins (proteins which carry cholesterol from the liver to the tissues of the body). Vitamin E also stops the oxidation of Polyunsaturated Fatty Acids (PUFAs) which can be found in our cell membranes. It is perhaps easy to imagine that if damage occurs to a cholesterol carrier, a red blood cell that carries oxygen or to a cell wall which controls cellular replication it has the potential to cause dis-ease?

PUFAs found in oily fish, nuts and seeds are vital to our health but they are particularly prone to oxidation (their chemical structure holds double bonds which contain hydrogen and this easily reacts with oxygen) which forms radicals. Vitamin E stops this process by donating an electron which stops a damaging chain reaction and preventing the rearrangement of cellular membranes and excessive production of arachidonic acid, which we associate with inflammation and dis-ease.

Carotenoids (the plant form of vitamin A) are a family of antioxidants including betacarotene, lutein and zeaxanthin which are particularly prominent in coloured fruits and vegetables - yellow, orange, green, red and purple varieties. Carotenoids, like vitamin E, inhibit lipid peroxidation and scavenge single oxygen radicals reducing potential damage within the body. Research suggests that carotenoids and tocopherols (vitamin E family) work together to provide a better antioxidant protection than when working alone and why it is vital to obtain a variety of coloured fruit, vegetables, nuts and seeds in our daily diets.

Vitamin C (L-ascorbic acid) is an essential water-soluble vitamin and like vitamin E it donates electrons to provide stability to ROS radicals however, it is not bound to membranes and rather works in our fluid internal environments. Vitamin C is often associated with immune health and that is because it protects lymphocytes (white cells of the immune system) from oxidative damage. During an oxidative burst phagocytes (cells that eat bacteria) release superoxide radicals to kill pathogens and Vitamin C reduces these toxic substances into a less harmful state.

Whilst we often take Vitamin C for colds it is clear to see that nutrition and how nutrients work is much more complex than taking a simple single supplement. Nutrients work in synergy, you could have all the vitamin C in the world but if you don't obtain the full team this antioxidant system will struggle to be effective. Vitamin C regenerates vitamin E and Copper, Vitamin E regenerates selenium - co-operation between these molecules leads to a synergistic cellular protection against a variety of ROS.

So should you take supplements if you think you are lacking certain nutrients? The simplest answer is no, probably not. The writing above should demonstrate that nutrients work in synergy and therefore a broad, seasonal and regular intake of fruits and vegetables is the best way to obtain antioxidants. Speak with your doctor and ask if you can check your nutritional status or speak to a qualified nutritional therapist as many factors such as the type of supplement and dosing which can turn a positive into a negative. In some cases, excessive supplementation can actually cause a pro-oxidant state and be quite damaging to the body; it is vital to speak to a professional person if you are on medication, smoke or drink or suffer from a pre-existing health condition.

If you are a healthy individual why not start broadening your diet in the first instance to support all the lovely antioxidants you consume through coloured veg, some examples are below:

Vitamin A - organ meat or orange vegetables such as sweet potato, squash and pumpkin

Vitamin C - fruits, berries, citrus fruits

Vitamin E - nuts and seeds, avocado, healthy vegetable oils (not processed oils), oily fish

Selenium - brazil nuts and seafood

B vitamins - meats, fish and whole-grains, such as quinoa.

Minerals - grains, vegetables, meats, fish, organ meats

You can find out many more examples over at:

Whilst there is much more I could talk about and this blog has been simplified significantly I hope you begin to see how antioxidants work and why vegetables and fruits are associated with reduced inflammation and less dis-ease.

As many readers will know I also run a canine nutrition business and it is for this reason that I include vegetables in the Pawsome diets that I create. Did dogs need vegetables in the wild? no maybe not. But was their world as toxic as it is now? Head over to to start healing your dog from the inside out.

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