The Conversation

  • Written by Jacqui Adcock, Research Fellow in Analytical Chemistry, Deakin University

Antioxidants seem to be everywhere; in superfoods and skincare, even chocolate and red wine. Products that contain antioxidants are marketed as essential for good health, with promises to fight disease and reverse ageing.

But are they really as good for us as we’re led to believe?

What are antioxidants?

The term antioxidant covers a wide range of molecules (atoms bound together by chemical bonds) that protect other molecules from a chemical process called oxidation. Oxidation can damage vital molecules in our cells, including DNA and proteins, which are responsible for many body processes.

Molecules such as DNA are needed for cells to function properly, so if too many are damaged, the cell can malfunction or die. This is why antioxidants are important. They can prevent or reduce this damage. In the body, uncontrolled oxidation is typically caused by highly reactive molecules known as free radicals.

What are antioxidants? And are they truly good for us? Products that contain antioxidants are marketed as essential for good health. Alpha/Flickr, CC BY

What is oxidation?

Oxidation is a common chemical reaction where electrons are transferred from one molecule to another. Electrons are one of the subatomic (smaller than an atom) particles that make up pretty much everything. As electrons move during an oxidation reaction, bonds can be broken and the structure of the molecules changed.

What are antioxidants? And are they truly good for us? Unpaired electrons make free radicals unstable and highly reactive. Author provided

Not all oxidation reactions are bad. They are essential for life and involved in many important processes. In cellular respiration, glucose (a sugar from the food we eat) is oxidised by oxygen (from the air we breathe), producing carbon dioxide, water and energy to fuel our bodies. Household bleaches oxidise coloured stains into colourless molecules.

Less desirable oxidation reactions include the rusting of metals and oxidative food spoilage.

What are free radicals?

Free radicals are simply molecules with one or more unpaired electrons. Electrons like to be in pairs, so unpaired electrons can result in unstable and highly reactive molecules. To become stable, the free radical must steal an electron from another molecule (or give one away). When a molecule loses an electron, that molecule has been oxidised and itself becomes a free radical.

This new free radical can steal an electron from another molecule, starting a chain reaction. This process permanently changes the structure of the molecules, causing irreversible damage.

What are antioxidants? And are they truly good for us? A free radical can steal an electron from another molecule, which then becomes a free radical.

But if an antioxidant is present, it can donate an electron to the free radical, stabilising it and stopping the chain reaction. The antioxidant sacrifices itself and is oxidised instead of the other molecule, becoming a free radical. But unlike most molecules, the antioxidant is able to stabilise the unpaired electron and does not become highly reactive. This process deactivates the antioxidant.

What are antioxidants? And are they truly good for us? An antioxidant donates an electron to a free radical and stops the chain reaction. Author provided

Free radicals aren’t always bad for you. Their highly reactive and destructive nature is used by the body’s immune system. Certain white blood cells, called phagocytes, can engulf foreign particles, such as bacteria, then seal them off and release free radicals to destroy them.

Free radicals are generated naturally by our bodies, but can be increased by lifestyle factors such as stress, poor diet, pollution, smoking and alcohol. Our bodies can handle some free radicals, but if too many are formed it can overwhelm the body’s normal defences.

Free radical damage is thought to be one of the causes of ageing and contribute to various diseases. For example, free radical damage to DNA can cause genetic mutations and promote cancer.

All antioxidants aren’t equal

So, if free radicals are dangerous and cause ageing and disease, and antioxidants can neutralise them, then getting more antioxidants should be good for you, shouldn’t it? Unfortunately, it’s not as simple as that. Yes, high antioxidant levels and low oxidative stress are associated with good health, but not all antioxidants are equal.

What are antioxidants? And are they truly good for us? A healthy diet is the most effective way to get antioxidants. www.shutterstock.com

Antioxidants come from many sources. Some are naturally produced in the body and some naturally occur in foods we eat. Antioxidants (natural or synthetic) can also be added to foods that don’t normally contain them, either for their (supposed) health value or to preserve the food (antioxidants also prevent oxidation in foods).

A healthy diet is the most effective way to get the antioxidants your body needs. Fruits, vegetables, grains, eggs and nuts are all useful sources of antioxidants. Despite the marketing hype, antioxidants found in so-called superfoods are no more effective than those in regular fruit and veg, so you’re better off saving your money.

But it’s a different story when it comes to antioxidant supplements. Research has found antioxidant supplements may cause more harm than good. A 2012 meta analysis of over 70 trials found antioxidant supplements are ineffective or even detrimental to health. The reasons are unclear, but the added nutritional benefits from consuming antioxidants in a healthy diet is likely to contribute to this. Also, the high concentrations of antioxidants associated with supplement use can lead to problems.

What are antioxidants? And are they truly good for us? Superfoods and regular fruit and veg both provide the same types of antioxidants. www.shutterstock.com

Too much of a good thing

There are a number of reasons why high concentrations of antioxidants may be harmful. At high concentrations, antioxidants may:

There is no magic pill, but a healthy diet can provide you with all the antioxidants you need to fight free radical damage.

Authors: Jacqui Adcock, Research Fellow in Analytical Chemistry, Deakin University

Read more http://theconversation.com/what-are-antioxidants-and-are-they-truly-good-for-us-86062

Politics

Scott Morrison at Australia-Israel Chamber of Commerce

QUESTION: I suppose one question I'll ask is about the role of social media, YouTube, Facebook. And the sort of thought process that we’re having as a nation of how we can create that sort of societ...

Scott Morrison - avatar Scott Morrison

Delivering the rail links Western Sydney needs

The Morrison and Berejiklian Governments will ensure the Western Sydney International (Nancy Bird Walton) Airport has a metro rail line in time for its opening.   The Prime Minister said his Gover...

Scott Morrison - avatar Scott Morrison

Nancy-Bird Walton immortalised at Western Sydney Airport

Australia’s biggest aviation project will honour one of the nation’s trailblazing stars of the sky.   The $5.3 billion Western Sydney Airport will officially become Western Sydney International (N...

Scott Morrison - avatar Scott Morrison

Business News

How to optimize your blog posts for SEO

Getting noticed on the Internet can be difficult if the blogs and articles that you put a lot of effort into aren’t optimized for SEO. Google is one of the leading sources that people use to find in...

Kyle Moore - avatar Kyle Moore

Why you should consider ditching your PR agency and doing it yourself

A new online platform is making running your own PR campaigns easy for small business owners and entrepreneurs – and it’s much more affordable than engaging a high-priced PR agency. The right media...

Jules Brooke - avatar Jules Brooke

Hideaways Bins

Small New Zealand company with big Australian presence wins international design award…for a rubbish idea How often do you think about the humble rubbish bin in your kitchen? For one family-run Kiw...

Hannah Parr - avatar Hannah Parr

Travel

Have An Unforgettable Vacation in Orlando

Family-friendly with unique theme parks, Orlando, Florida is the place to go for an unforgettable vacation. Head to the beach, spend time in Disney World, and visit The Wizarding World of Harry Pott...

News Company - avatar News Company

Airports and Customs in Australia: Everything you need to know to discover the country by plane

Australia is such a huge country that the beginning of air travel represented a very important step in the development of the country and communication among its citizens. Before air travel, it took...

News Company - avatar News Company

The Gold Coast is famous for fun but it is also famous for horrible traffic issues

The Gold Coast is a great place for a holiday but there are problems that tourists need to be aware of. The Gold Coast airport is a busy place. Thousands of visitors arrive every day from around the ...

Holiday Centre - avatar Holiday Centre