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Antioxidants are just that: they fight (anti) oxidation. 

The chemical process of oxidation is like rusting metal. Oxidation is also the reason why apples, bananas, and avocados go brown when peeled and exposed to air - they're getting oxidized. 

What are oxidation and free radicals?

Understanding the process of oxidation requires a little knowledge of basic chemistry. (I’ll try not to bore you too much here!) 

Atoms are surrounded by negatively charged electrons that orbit the atom in layers called shells. Once the outermost layer contains all the electrons it can hold, the next layer begins filling up.

When an atom has a full outer shell, it is considered to be stable. However, if an atom is missing an electron, it is unstable and willing to react with any substance quickly to become stable. These are known as free radicals.

This may not seem like a problem, but free radicals are so highly reactive, they are willing to grab onto any other extra electrons they find. They act erratically and bounce all over the place in search of other atoms or molecules to which to bond.

When oxygen molecules (O2) split into single atoms that have unpaired electrons, they too become unstable free radicals. They can become so aggressive that they can break bonds between molecules that are already paired up to satisfy their desire for stability. As this process continues, oxidative stress begins.

Oxidative stress breaks down and damages body cells. Over time, the body loses its ability to fight off the effects of free radicals. More free radicals result and additional oxidative damage is created. As more damage to cells occurs, we start to see signs of ageing, wrinkles, and a range of degenerative diseases.

Free radicals in the body cause inflammation and can contribute to diseases like cancer, diabetes, and heart disease (to name a few).

The antidote to the process of oxidation is the antioxidant.

What are antioxidants?

Vitamins like A, C, and E are examples of antioxidants. So are other compounds in foods like carotenoids and phenols. These compounds sacrifice their electrons to stop the oxidation process; this is why squirting some lemon juice (loaded with vitamin C) on your sliced apples, bananas and avocados slow down the browning process.

But don’t think that all oxidation in the body is terrible. It’s not. Your body naturally oxidizes compounds all the time when it’s doing good things like metabolizing nutrients or exercising.

We can easily throw off that balance with exposure to too much alcohol, smoking, or environmental pollutants. Even over-exercising or too much sun exposure can create too much oxidation.

The best sources of antioxidants to combat this effect are nutritious whole foods including colourful fresh produce like blueberries, purple cabbage, red bell peppers, and orange carrots. In fact, the more colourful and darker the plant is, the higher levels of antioxidants it usually has. Chemicals that give the plants their deep colours are often the antioxidants themselves.

Antioxidants in food

The best sources of antioxidants are those found in food. Following are several common antioxidants and the foods in which they’re found:

• Vitamin A - Found in liver, dark leafy greens (kale, spinach, chard), orange fruits and veggies (mangoes, carrots, squashes, peppers, etc.)

• Vitamin C - Found in bell peppers, citrus fruit, berries, and leafy greens

• Vitamin E - Found in leafy greens, nuts (walnuts), and seeds (sunflower and pumpkin)

• Carotenoids (including beta-carotene, lycopene, etc.) - Found in tomatoes, carrots, squash, sweet potatoes, and salmon

• Phenols - Found in green tea, black tea, coffee, cocoa, red wine, and berries

Blueberries are probably one of the most studied antioxidant foods and my favourite addition to an antioxidant-rich anti-inflammatory brain-healthy diet. They contain a range of phytochemical compounds (plant chemicals) and are very high in anthocyanins (the blue-coloured compound).

For those of you interested in the geeky science stuff (like me), you may be interested to know that the antioxidant capacity of foods can be measured in a laboratory to determine its "oxygen radical absorption capacity," or "ORAC." And blueberries have one of the highest ORAC levels of any food!

FUN FACT: Some studies estimate that the highest source of antioxidants in the average American’s diet doesn’t come from berries but from coffee! Can you imagine how much healthier people could be if they added a few more servings of antioxidant-rich fruits and vegetables to their plates?

Antioxidant Foods vs. Supplements

While antioxidant supplements have been tested, their results haven’t been as good as many hoped. Compared with eating a nutrient-dense antioxidant-rich colourful array of plants, antioxidant supplements have fallen short.

Many studies of antioxidant supplements haven’t shown any benefit against heart disease, cancer, or other diseases. And these are diseases that are known to be reduced in people who eat a lot of foods that are naturally full of antioxidants.

In fact, too much of any individual antioxidant, like when overdoing supplements, can be harmful. Too much vitamin A is linked to an increased risk of hip fractures and prostate cancer. Too much beta-carotene increases the risk of lung cancer in smokers. Too much vitamin E increases the risk of prostate cancer, lung infections, or heart failure.

One of the reasons why we think that antioxidant foods work oh-so-much better than antioxidant supplements is because of synergy. The concept of synergy means that by taking one component out of healthful food, the antioxidant, for example, it loses the effect it has when combined with all the other healthy components it came with from nature. This is the difference between eating a whole orange and taking a vitamin C supplement. The orange is going to have more than just vitamin C, and many of those compounds will work together for overall health better than just isolating one and having higher-than-normal doses of it.

Conclusion

There are antioxidant vitamins (A, C & E) and other antioxidants like carotenoids and polyphenols. They’re highest in colourful fruits and vegetables, nuts and seeds, some meats, tea, coffee, and cocoa.

You can’t replace a diet full of nutrient-dense antioxidant-rich whole foods with supplements. So stick with the foods!

Which antioxidant-rich foods and drinks are your favourites? Let me know in the comments below.

One of my favourites is a smoothie combining mixed berries (blueberries, black cherries, strawberries, blackberries, and raspberries) with coconut milk and collagen protein powder (stay tuned for an upcoming blog about this wonderful ingredient).

As always, I welcome your thoughts and value your feedback. Let me know what you think by dropping me a line or commenting below.

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