Fruit and vegetables are packed full of goodness and often contain a number of essential vitamins and minerals that cannot be found in other types of foods or they may contain higher levels of these nutrients than other foods.
They play a significant role in human nutrition, especially as sources of vitamins [C (ascorbic acid), A, thiamine (B1), niacin (B3), pyridoxine (B6), folacin (also known as folic acid or folate) (B9), E], minerals, and dietary fiber. Their contribution as a group is estimated at 91% of vitamin C, 48% of vitamin A, 30% of folacin, 27% of vitamin B6, 17% of thiamine, and 15% of niacin in the diet.
Fruits and vegetables also supply 16% of magnesium, 19% of iron, and 9% of the calories. Legume vegetables contribute about 5% of the per capita availability of proteins in the diet as their proteins are of high quality due to their content of essential amino acids. Other important nutrients supplied by fruits and vegetables include riboflavin (B2), zinc, calcium, potassium, and phosphorus.
Fruits and vegetables in the daily diet have been strongly associated with reduced risk for some forms of cancer, heart disease, stroke, and other chronic diseases. Although antioxidant capacity varies greatly among fruits and vegetables, it is better to consume a variety of commodities rather than limiting consumption to a few with the highest antioxidant capacity. There is increasing evidence that consumption of whole foods is better than isolated food components such as dietary supplements and nutraceuticals.
The Dietary Guidelines encourage consumers to enjoy five a day, i.e., eat at least 2 servings of fruits and at least 3 servings of vegetables each day, to choose fresh, frozen, dried, or canned forms of a variety of colors and kinds and to choose dark-green leafy vegetables, orange fruits and vegetables, and cooked dry beans and peas often.
If you generally do not eat a lot of fruit and vegetables and are finding it difficult to add a few more portions to your daily diet, here are a few ideas to start you off:
• Start the day with a glass of freshly squeezed orange or grapefruit juice
• Add sliced banana, strawberries, kiwi to your breakfast cereal
• Have a fruit smoothie for breakfast made with banana, yoghurt and other fruit
• Add lettuce, sliced tomato, cucumber to sandwiches
• Add diced red, orange and green pepper to mayonnaise
• Choose dried fruit snacks over chocolate
• Add sliced fruit to yoghurt or other desserts
• Choose healthy dips with vegetable crunches over unhealthy snacks
• Make healthy homemade vegetable soups for lunch or dinner
• Always have a side salad of lettuce, cucumber, tomato and onion with your meal
• Try different and exotic salads for a change
• Try to eat 3 different vegetables with your main meal
• Have a fruit salad for dessert
• Make healthy risottos with fresh vegetables
Some components of fruits and vegetables (phytochemicals) (Table 1) are strong antioxidants and function to modify the metabolic activation and detoxification/disposition of carcinogens, or even influence processes that alter the course of the tumor cell. They are required for maintaining good health.