Nutrition 101– Antioxidants
Nutritionists tend to throw terms like ‘carbs’, ‘vitamins’
and ‘minerals’ around like everyone knows what they are. But
many people, if asked, couldn’t actually tell you what a vitamin
is, or why your body needs them. Yes, organic food usually contains more
vitamins and minerals, but what does this actually mean for your health?
Well, welcome to this series of explanations of the most used nutritional
terms – what they are, what they do, and how to get them. This month:
Antioxidants
It’s well known that the greater your daily intake of fruit and
vegetables, the lower your risk of various diseases including cancer,
cardiovascular disease and diabetes. There are many possible reasons for
this, including the vitamins, minerals and fibre they contain. Yet science
is now revealing that plant foods contain some five to ten thousand compounds
other than the known vitamins and minerals, and many of them have been
found to be powerful antioxidants. Some scientists now think that these
antioxidants may be the main reason fruits and vegetables are so health
promoting.
But what exactly is an antioxidant? Put simply, an antioxidant is capable
of quenching unstable molecules known as free-radicals. Free radicals
are a natural by-product of normal reactions in your body, though they
are increased by various things like pollution, radiation, fried and burnt
foods, and excess sunlight. Unchecked, free radicals cause damaging chain
reactions that damage your cells, disrupting normal reactions in your
body, burdening your immune system, speeding ageing processes, and potentially
initiating heart disease and cancer. Antioxidants come to your rescue
and neutralize these excessive free radicals. Examples of the best antioxidant
nutrients include vitamins A, C, and E; the minerals zinc and selenium;
and many of these plant compounds like carotenoids, flavonoids, anthocyanins,
polyphenols and more. Specific examples include lycopene in tomatoes and
resveratrol in red grape skins (and thus red wine!).
The best antioxidant foods
Phytonutrients are present in all foods, though the following foods are
your best sources and should be regular features in a healthy diet, with
organic versions best of all:
Berries including blueberries, blackberries, strawberries
and raspberries are rich in flavonoids called anthocyanins, and have the
highest antioxidant activity of any plant foods.
Cabbage, broccoli, cauliflower and Brussels sprouts
are rich in glucosinolates - they can slow thyroid function but are also
one of the best proven cancer preventing component in vegetables.
Dark green, red, and orange vegetables are rich in flavonoids
and carotenoids - powerful antioxidants that are also anti-inflammatory,
anti-allergenic, collagen stabilising, artery protective, and can discourage
the growth of established tumors.
Tomatoes and watermelons are rich in the carotenoid
lycopene - an antioxidant beneficial in the prevention and treatment of
breast and prostate cancers.
Green tea and red wine are rich in polyphenols - potent
antioxidants with cancer-protective and anti-ageing effects.
Garlic and onion contain sulphur-based phytonutrients
such as allicin in garlic - powerful antioxidants known to aid detoxification,
heavy metal removal, general connective tissue repair and cardiovascular
protection. Regular consumption of garlic and onion can significantly
reduce the risk of heart disease and cancer.
Organic produce and antioxidants
Evidence is growing that shows organic crops contain higher antioxidant
levels. Researchers have confirmed more lycopene in organic tomatoes,
more flavonols in organic apples, more resveratrol in organic red wine,
higher polyphenols in organic potatoes, peaches, pears, blackberries,
strawberries and corn, and higher lycopene, beta-carotene and polyphenols
in organic tomatoes.
A recent Danish literature review estimated, from the limited amount
of evidence so far, that organically grown vegetables will tend to have
10-50 per cent more antioxidants than conventionally cultivated vegetables,
and concluded ‘if antioxidants are an important determinant of the
nutritional value of fruits and vegetables then vegetable and fruit products
grown in organic agriculture would be expected to be more health promoting
than non-organic ones’. The American-based Organic Center for Education
and Promotion has also conducted a major scientific review of this issue
and found that ‘current evidence suggests that organic farming methods
increase average concentrations of antioxidants in selected fruits, vegetables
and grains’.
Wishing you the best of health,
Shane Heaton
Nutritionist
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