What is an antioxidant?
Antioxidants are found in the diet and are essential in preserving good health. There are different types of antioxidants that each one has a slightly different role. The types and manner in which they serve and protect us is discussed below.
What are free radicals?
In order to discuss the health benefits of an antioxidant, it will help to know some background on free radicals.
Free radicals are molecules that have unpaired electrons, making them highly reactive (electrons normally come in pairs). In this highly reactive state, they cause damage by stealing an electron from other cells, thereby altering the structure or function of that once healthy cell. This makes them more susceptible to disease such as cancer, heart attack and stroke.
Where do free radicals come from?
Some free radicals are produced naturally as a by-product of reactions that occur within our body, for example, when turning food into energy or during physical activity. They can also be created by smoking, radiation, air pollution and UV light exposure.
How do antioxidants help?
Consuming antioxidant rich foods are important to protect us from the damage free radicals can cause. Antioxidants do this in one of two ways –
1. They destroy the free radical molecules by breaking them down.
2. They can provide an electron to the free radical to make it have a complete electron pair, therefore
rendering them harmless. The antioxidant does not become an electron scavenger (like a free radical)
after donating one of its own.
An antioxidant will be used up as a result of neutralising the free radicals. It is therefore important to eat dietary antioxidants to replace the ones that are used.
Potential health benefits of antioxidants
There is a lot of current evidence that supports the role of antioxidants in preventing or slowing the progression of cardiovascular disease, cancers, age related eye disease, osteoporosis and potentially diabetes and neurodegenerative disease e.g Alzheimer’s disease. Despite this, results from clinical trials have differed and are therefore inconclusive. Further research needs to be undertaken before exact recommendations can be made and conclusions drawn.
What is known for sure is the importance of receiving your antioxidant intake from food sources rather than supplements. The greatest health benefits are seen with the consumption of a variety of antioxidant types, as they all have different protective properties – a balanced diet will provide this variety and there is plenty of reliable evidence to support the health benefits of a diverse diet.
There has, however, been far less evidence to support the health benefits provided by supplement forms of an antioxidant (s). Additionally, good food sources rich in antioxidants will provide lots of other beneficial nutrients to help keep you healthy! All of their beneficial properties work together to provide optimal health.
Antioxidant rich foods
Below is a list of some different types of antioxidants and the main food sources they are found in. Additional information can be found in my article about ‘Colour Food’.
* Selenium is not technically an antioxidant but it is a part of antioxidant enzymes. The amount of selenium found in plants and crops will vary depending on the content in the soil. Animals that eat crops grown in selenium rich soil will have higher selenium content in their muscles.
Contact us for results focused advice about eating healthy
This article eating healthy as a student was written by our nutritionist Belinda Elwin who is a Dietitians Association of Australia member and Accredited Practising Dietitian.
If you have questions about eating healthy or would like advice about nutrition, contact your local doctor who will arrange for you to see a dietitian in Sydney. For healthy eating advice, Contact us today!
- Position Statement – Cancer Council Australia
- Antioxidants and Cancer Prevention – National Cancer Institute
1. Lorenz M, Jochmann N, Von Krosigk A, Martus P, Baumann G, Stangl