Anti-oxidants and diet

Anti-oxidants

What are they? 

What do they do? 

What’s a ‘free radical’? 

What’s the best way of taking anti-oxidants? 

How many should I take? 

Anti-oxidants do what it says on the packet - they fight oxidation. Oxidation is a normal chemical process that takes place in the body, but this process produces potentially damaging molecules called free radicals. Free radicals are nasty - they are highly unstable, and damage cells, proteins and DNA in the body. They are also present in cigarette smoke, pollution, and herbicides. Free radical damage accumulates with age (Healthchecksystems 2012).

Anti-oxidant Wonder Woman!

Anti-oxidants work firstly by stabilising the free radicals that are formed in the body, secondly by preventing their formation, and thirdly by acting as scavengers, preventing cell and tissue damage. They are definitely the good guys!

Taking anti-oxidants

You might think that taking supplements of anti-oxidants would be easier and more effective than eating more fruit and vegetables. The opposite is true - large doses of anti-oxidants can be bad for you, as many studies have shown (Graat et al. 2002; Lichtenstein & Russell 2005). So don’t take supplements, because of the risk of toxicity. Instead, eat more fruit and veg - it’s thought that the other nutrients that are present in fruits and vegetables work with the anti-oxidants and provide a protective effect (Parnes n.d.). So, in other words, eating anti-oxidants on their own in a supplement can be problematic - it's safer and better to get your anti-oxidants the natural way, by eating them.  Remember that free radical damage increases with age, so the older you are the better your diet needs to be. The guidelines are between 5-8 portions of fresh fruit and vegetables daily - so the older you are, the more portions you need!

 Some useful anti-oxidants

Vitamin E is found in vegetable oils, walnuts, peanuts, almonds, seeds, olives, avocado, wheat germ, liver, and leafy green vegetables. It’s one of the anti-oxidants that is very effective at stabilising free radicals.

Vitamin C  works synergistically with Vitamin E, and is particularly effective against the free radicals caused by pollution and smoking. For good sources of vitamin C, look to citrus fruits (like oranges and grapefruit), broccoli, leafy green vegetables, tomatoes, peppers, potatoes, cantaloupe, and strawberries. But if you are using a Vitamin C supplement, don’t take more than 2000 mg a day - it can cause gut problems.

Beta-carotene - thought to be the best scavenger of free radicals. High doses turn your skin yellow but are not toxic, but a good diet should provide all you need. Common sources of beta-carotene include melon, mangoes, papaya, pumpkin, peppers, spinach, kale, squash, sweet potatoes, and apricots.

Selenium - You can find selenium in seafood, beef, pork, chicken, Brazil nuts, brown rice, and whole wheat bread.

Anthocyanins give fruit and vegetables a deep purple, blue or red colour, and can reduce the risk of diseases such as dementia, diabetes and stroke (Jing et al. 2008). They posses powerful anti-oxidant properties (Wang et al. 1997).  Blueberries, blackberries, purple grapes, cranberries, and raspberries are all rich sources of anthocyanins. 

Some of the other benefits of anti-oxidants

Bibliography

Graat, J.M., Schouten, E.G. & Kok, F.J., 2002. Effect of Daily Vitamin E and Multivitamin-Mineral Supplementation on Acute Respiratory Tract Infections in Elderly Persons A Randomized Controlled Trial. JAMA: The Journal of the American Medical Association, 288(6), pp.715–721.
 

Healthchecksystems, 2012. Understanding Free Radicals and Antioxidants. Available at: http://www.healthchecksystems.com/antioxid.htm [Accessed May 18, 2012].

Jing, P. et al., 2008. Structure−Function Relationships of Anthocyanins from Various Anthocyanin-Rich Extracts on the Inhibition of Colon Cancer Cell Growth. Journal of Agricultural and Food Chemistry, 56(20), pp.9391–9398.

Lichtenstein, A.H. & Russell, R.M., 2005. Essential Nutrients: Food or Supplements? Where Should the Emphasis Be? JAMA: The Journal of the American Medical Association, 294(3), pp.351–358.

Wang, H., Cao, G. & Prior, R.L., 1997. Oxygen Radical Absorbing Capacity of Anthocyanins. J. Agric. Food Chem., 45(2), pp.304–309.