Choosing certain foods by colour is one way to ensure you get a well-balanced diet. Dr Wynnie Chan explains how to colour-code your platter

To stay healthy, we need to eat a variety of foods. Since different foods contain varying amounts of nutrients, eating a wide-ranging diet ensures we meet our requirements for protein, fat, carbohydrates, fibre, vitamins and minerals. This helps to keep our bodies in top condition. One of the ways to ensure you are getting this balanced assortment, is to choose foods based on their colour.

Over the past few years, there has been increasing scientific evidence to suggest that there are substances in foods - particularly fruits and vegetables - that can help keep cancer and heart disease at bay. These substances are called phytochemicals (phyto meaning 'from plants'), and include carotenoids and flavonoids, which are naturally occurring pigments that give fruits and vegetables their vibrant and distinctive colour. They are responsible for the orange of carrots and sweet potatoes, the red of cherries and tomatoes, and the dark green of spinach, broccoli and spring cabbage.

How colour works
Diseases like cancer and heart disease are often attributed to the effects of free radicals. Free radicals are the natural by-products of ongoing biochemical reactions which are produced during metabolism and by the body's immune system. However, environmental factors such as pollution, radiation, pesticides, cigarette smoke and herbicides can also be a source of free radicals. If left to build up in the body, free radicals can cause damage to both the structure and insides of our cells. If our body cannot repair the damage, these cells are more likely to develop cancer. In the case of heart disease, free radicals can play a part in the formation of deposits in our blood vessels. These accumulated deposits can cause the vessels to narrow and affect blood supply to the heart. If the blood vessels become completely blocked, blood will not be able to flow through to the heart, which can lead to a heart attack.

So what role does the colour of food have on all this? The natural carotenoid and flavonoid pigments found in food have antioxidant properties, which means they have the ability to fight off or neutralise free radicals in the body. A government report on the Nutritional Aspects of the Development of Cancer published in 1998, concluded that there was evidence to suggest that high intakes of fruits and vegetables were protective against some cancers. This is most likely due to the unique range and mix of vitamins, minerals and other phytochemicals they possess.

So the next time you go to your local supermarket, let your eyes do the choosing and load your trolley up with as many differently coloured fruits and vegetables as you can. These will satisfy your visual senses and give your body greater strength to fight off disease.

Colourful recipes

To make food that's a feast for your eyes as well as your stomach, try the following recipes:

1. Tropical fruit salad
2 kiwi fruits, sliced
1 can pineapple chunks
1 ripe mango, sliced
12 whole strawberries
1/4 pint unsweetened orange juice

Combine in a large mixing bowl. Serve with creme-fraiche or low-fat yoghurt for a delicious dessert. Serves 2, as a dessert

2. Rainbow pepper salad
1 red pepper, sliced in thin strips
1 green pepper, sliced in thin strips
1 yellow pepper, sliced in thin strips
1 orange pepper, sliced in thin strips
1 red onion, sliced

Dressing
1 green chilli, deseeded and sliced
2 tbsp lime juice
2 tbsp grapeseed oil
1 tbsp toasted poppyseeds
1 tsp sugar
salt and pepper to taste

Toss ingredients together. Serve as an accompaniment to either chicken or fish. Serves 4

3. Sunshine fruit salad
2 large oranges, peeled, sliced in sections
4 dried dates, chopped
1 pink grapefruit, peeled, sliced in sections
1 tbsp orange water (N.B. you can find this at supermarkets or delicatessens and is similar to rose water favoured in Middle Eastern cookery)

Combine ingredients together in a bowl, chill before serving. Serves 2

4. Boozy fruit combo
1/2 honeydew melon, sliced
20 seedless red grapes, halved
1 avocado pear, sliced
2 tsp honey
1 tbsp dark rum

Combine ingredients in a large bowl. Chill before serving.

5. Salad daze
2 heads of chicory
1 bunch watercress, torn
1 small red leaf lettuce, torn
20 cherry tomatoes

Dressing
2 tbsp olive oil
2 large garlic cloves, crushed
2 tbsp tarragon wine vinegar
1 tsp grain mustard

Combine salad ingredients in a large bowl, and chill until ready to serve. Dress the salad just before serving. Salad goes well with baked salmon and a baked sweet potato. Serves 4.

6. Hearty vegetable soup
1 large leek, sliced
2 carrots, peeled and chopped
1 large turnip, peeled, chopped
2 garlic cloves, peeled and pureed
1 pint chicken or vegetable stock
4 Desiree potatoes, peeled, chopped
6 large tomatoes, chopped
1 large onion, chopped
1 tbsp olive oil
1 handful of basil leaves, chopped
salt and pepper to taste
ground nutmeg to taste
175g grated reduced-fat cheddar cheese

Heat oil in a stock pot, add onion and garlic and fry over medium heat for 10 minutes. Add all the vegetables except the tomatoes, stir, then add stock. Bring to a boil, then reduce heat, cover and simmer for 30 to 40 minutes. Add tomatoes and basil, and simmer for another 20 minutes. Add salt and pepper and nutmeg to taste. Sprinkle with cheese just before serving. Serve with chunks of wholemeal bread for a hearty lunch. Serves 4.