Understanding Antioxidants

So we’ve all heard of antioxidants - but do you know what they do? Before I dive into that, we need to talk about something called free radicals (also known as ROS).

Free radicals are essentially a by-product of breathing oxygen. The more oxygen you breathe, the more free radicals your body produces – especially when you exercise. These free radicals are highly reactive (it's in the name) and can harm the other cells in your body, which in turn prevents these cells from functioning normally. This leads to muscle fatigue, inflammation and reduced immune function.

This is where antioxidants come in. Antioxidants minimize the impact of free radicals. This is what helps to reduce our fatigue and soreness post-exercise, as well as reducing the decrease in immune function.

There are two types of antioxidants. Endogenous and Exogenous. Endogenous antioxidants are ones that your body makes. Exogenous antioxidants are ones that you get from the food you eat (just think exo = external).

Endogenous antioxidants do a really good job at controlling your oxidative stress, but sometimes your body needs some help – which is where some antioxidant-rich foods come in. 

The vast majority of dietary antioxidants come from fruits and vegetables containing Vitamins A, C and E as well as Selenium, Polyphenols and Flavonoids. High-dose antioxidants include berries, dark chocolate, beans, green vegetables (think broccoli, spinach, kale) and a variety of herbs and spices. As for beverages, coffee and tea (without cow’s milk) and red wine are all quite high. 

Important side note for the wine – it’s more important to stick to the national guidelines of less than 10 standards a week and no more than 4 standards on a single day. 

Now that you have a foundation of what antioxidants are and how they work, you might be thinking – the more the better right? If I could get rid of all those free radicals with lots of antioxidants, then surely I’d never be sore after a workout and would never be sick. Why can’t I just take a supplement to get all the antioxidants I’d ever need?

Well, sometimes there is too much of a good thing. This means that there is a sweet spot of free radicals in our bodies. If we never had any free radicals, our body would never adapt to overcome that soreness and fatigue. This means that our bodies would be a lot less efficient at getting stronger and fitter from our workouts, as well as not being as capable to fight off pathogens and regulate cell growth. This is one of the main arguments against antioxidant supplementation. Given the extremely high doses of antioxidants in supplements, they can neutralise too many free radicals at once. 

Here is a breakdown of two common supplements found in Australia today showing the quantities of Vitamins A, C, E and Selenium, and the RDI (Recommended Daily Intake) and AI (Adequate Intake) levels for men and women aged 19-70yrs.

These numbers show the drastically high levels of each nutrient found in these supplements; well above the RDIs and AI. Whilst there may not be any serious negative consequences of supplementation, it also won’t be beneficial for the average person. 

Ultimately, the moral of the story is that whilst we want to minimise the free radicals in our bodies, they also do serve a purpose. Ensuring that you eat plenty of colourful fruits and vegetables will go a long way to achieving that sweet spot whilst providing you with plenty of other benefits.

Supplementing may be beneficial for a short time frame, in times of excess need like illness or intensive training.

Written by Andrew Holland for Food Culture