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).
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| 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.
