GP Q/A: What are antioxidants and why are they good for you?

Reader question:

Hi Dr Joe,

There’s so much information about antioxidants, it’s hard to know what to trust and to do. What exactly are antioxidants, why are they good for you, what food/drink at they in and how much do you need? Is it of benefit having more than you need? They put antioxidants in skin creams etc.

Thanks a lot,
Jenny, TAS

GP response:

Dr Joe Kosterich MBBS, General Practitioner and Editorial Advisory Board Member of the Virtual Medical Centre and Parenthub responds:

We have all seen what happens to metal which “oxidises” – it rusts. In the body the role of antioxidants is to “mop up” molecules called free radicals which can damage or “rust” our cells. Free radicals are all around us and impossible to avoid altogether, and the body needs a small number of free radicals to function effectively. However too many free radicals cause damage. You need a balance between the number of free radicals and antioxidants in the body.

One part of creating a healthy balance is to reduce the number of free radicals that form in the body. Simple things like not smoking, reducing stress, drinking alcohol in moderation and avoiding over-exposure to sunlight all help. The other side of the coin is to increase the number of antioxidants, but don’t overdo it. Like virtually all things in health, we need a certain amount but more is not always better.

So how can you increase your intake of antioxidants? The best way is to eat foods rich in antioxidants. If this is not happening then the other option is to take antioxidant supplements.

Vitamins A C and E are natural antioxidants. They are best obtained from our diets by eating plenty of fresh fruits and vegetables. Almonds are a good source of vitamin E as are avocadoes. Carrots are rich in vitamin A and citrus is rich in vitamin C.

Here is a list of natural antioxidants and foods, which are rich in them and helpful minerals too:

• Flavonoids such as those found in green tea, red wine and citrus fruits.
• Isoflavonoids abundant in soybeans and soy products like tofu as well as lentils, peas and milk.
• Caratonoids especially beta carotene found in orange and yellow fruits and vegetables including pumpkin, oranges and paw paw.
• Polyphenols found in herbs including thyme and oregano and products containing cocoa such as dark chocolate.
• Manganese dietary sources of which include fish, lean meat, milk and nuts.
• Selenium which can be obtained from a diet containing whole grains, seafood, offal and lean meat. However there is some debate regarding whether selenium itself, or selenium-containing proteins have antioxidant properties.
• Zinc which is also found in fish, lean meat, milk and nuts.

So what about antioxidant supplements?

Despite marketing claims, evidence shows the health benefits of taking antioxidant supplements are modest at best. Antioxidants have been tested for preventing a range of health conditions, from heart disease to Alzheimer’s, cancer to eye diseases. Most studies suggest no benefit at all. A few have shown detrimental effects, for example an increased risk of lung cancer in people taking high doses of vitamin A.

Although eating antioxidants in fruit and vegetables is beneficial, artificial supplements which include only the antioxidants (and exclude other healthy substances found in fruit and vegetables such as fibre) are unlikely to benefit one’s health. They should only be taken if your diet is inadequate. Eating a healthy, balanced diet which contains five servings of vegetables and two servings of fruit each day is the best way to obtain enough antioxidants.

Antioxidants are also good for the skin and are added to anti-ageing skin creams. This may be more about marketing than substance so be wary of expensive price tags.