Colour
your world with a plateful of disease-fighting foods by discovering a full
spectrum of good-for-you hues.
Apples aren't red by accident. And they're not made that way just to look
pretty, either. In nature, beauty always has a reason, and coloured foods can
encourage us to eat them (and spread their seeds).
Plant-eating animals can use colour to identify edible materials, and the
intensity of the colour signifies ripeness. But scientists have also found that
those pigments are created by a group of highly beneficial anti-oxidants called
carotenoids, which mop up harmful free radicals in the body. Red and yellow
hues signifying the presence of carotenoids are nature's advertisement for
immune-boosting, cancer-fighting properties.
The Dieticians' Association of Australia (DAA) recommends five servings of
vegetables and two of fruit each day, while the Australian Department of
Health's Guide To Healthy Eating advises that 40 per cent of your daily diet
should consist of fruit and vegetables.
You also need variety, including each of these colour groups daily: red,
orange, green, yellow, blue/purple and white. Mix as many hues as possible with
every meal. The deeper the colour, the higher the nutrient value. "The
most crucial colours of all are green and orange," says Katherine Warth,
dietician and spokeswoman for DAA. "Never go without either ... and try a
new food each week to boost variety even more."
RED
Signal for: Lycopene
Find it in: Tomatoes, persimmon,
watermelon, pink grapefruit
This carotenoid is a fierce cancer-fighter and can also help prevent heart
disease by inhibiting the formation of harmful LDL cholesterol. The deeper the
red or pink colour, the higher the lycopene content. Says Warth, "Studies
have shown that a high intake of tomatoes, which are rich in lycopene, can
reduce the risk of prostate cancer quite significantly."
Lycopene can also protect against cancers of the digestive tract, stomach and
lungs. It's a fat-soluble substance, and is more readily available from cooked
tomato products and juices than raw ones. "It's better to cook your
tomatoes with a little olive oil, or at least mix them into a salad with some
oil on it so that your body can best absorb the lycopene," says Warth.
ORANGE
Signal for: Beta-carotene
Find it in: Oranges, carrots,
mangoes, pumpkin, sweet potato, apricots, squash, rockmelon, pawpaw
Beta-carotene is a major anti-oxidant which lowers cholesterol and converts it
to vitamin A, an immune booster that helps fight off colds, flu, cystitis and skin
problems. "A study of smokers showed that those who ate more beta-carotene
had a lower incidence of lung cancer," says Warth. She adds that this was
true only when the beta-carotene was acquired from food, not a supplement.
Vegetables containing beta-carotene benefit from being cooked lightly to
release maximum amounts. Like lycopene, it's fat soluble, so using a little oil
will help your body absorb it. These orange fruits and vegies are also high in
that other great immune-booster, vitamin C.
GREEN
Signal for: Isothiocyanates, folic
acid
Find them in: Cruciferous vegetables
(the cabbage family), spinach, bok choy, kale, peas, artichokes, asparagus
Sulphur-based sinigrin, a substance unique to the cabbage family (which
includes brussels sprouts, broccoli, cabbage, cauliflower), converts into
anti-oxidant isothiocyanates, which cause pre-cancerous cells to destroy
themselves.
Isothiocyanates give broccoli and brussels sprouts their
distinctive smell, but the more pungent and strongly flavoured they are, the
better, says Warth. Also present is folic acid, which is in its highest
quantity in chlorophyll-rich dark-green leafy vegetables.
Folate works to
prevent birth defects, such as spina bifida, and is a dietary essential for
women who are (or are trying to become) pregnant.
YELLOW
Signal for: Lutein, zeaxanthin
Find them in: Yellow corn, bananas,
yellow capsicum, honeydew melon
These two carotenoids work together to help maintain sharp, healthy eyesight.
They are used in the area of the retina called the macula, which is the centre
for sharp, focused vision. They protect the eyes from long-term light damage.
We need to eat about 5mg of lutein and 1mg of zeaxanthin every day for adequate
eyesight protection, so it's vital to include a large splash of yellow.
Bananas are worth a special mention for their high potassium content. They can
help decrease the risk of stroke, lower blood pressure, relieve heartburn,
prevent stomach ulcers and even aid in abating diarrhoea.
PURPLE/BLUE
Signal for: Anthocyanins
Find them in: Blueberries, dark
cherries, prunes, blackcurrants, cranberries, red wine, red apples, black grape
juice, blackberries, strawberries, beetroot, figs
The blueberry is a tiny hero. It contains more anti-oxidants than any other
fruit or vegetable. Anthocyanins have remarkable anti-bacterial powers, useful
for tackling E coli, urinary tract infections and gastrointestinal upsets.
They're also anti-inflammatory, which is why blackcurrant syrups are used in
cold and throat medicine.
The anti-oxidants in purple or blue fruits help prevent nerve cells in the
brain from deteriorating, and possibly help guard against the effects of ageing
in general. Anthocyanins may also have a beneficial effect on heart disease by
inhibiting blood clots.
WHITE
Signal for: Flavonoids, allicin
Find them in: Onions, garlic,
celery, leeks, pears, shallots, white wine, endive, chives
Allicin has been shown to inhibit abnormal cell growth, and flavonoids are
important anti-oxidants. The sulphur compounds in these types of produce can
help raise levels of beneficial HDL cholesterol and lower dangerous levels of
blood fats called triglycerides, as well as easing the inflammatory response of
asthma and breaking up catarrh secretions caused by colds and flu.
Pears stand
out because, although they have white flesh, they are covered by green skin.
Just beneath the skin lies a soluble fibre called pectin, says Anne Egan,
dietician and co-author of Meals That
Heal (Rodale Press, $55). Pectin can help prevent haemorrhoids, lower
cholesterol and reduce the risk of colon cancer.
