Fresh vegetables are naturally low in fat, salt and sugar, making them an excellent food choice. Visit the recipe section of this website to discover delicious ways with vegetables.
Vegetables provide energy, vitamins, minerals and fibre and there is growing evidence of additional health benefits from a range of phytonutrients.
Some vegetables contain higher levels of carbohydrate and are often called starchy vegetables. These are usually roots and tubers (see vegetable classifications) such as potatoes, yams, kumara, taro and sweet corn. The starchy vegetables are higher in energy (kilojoules) because of their carbohydrate content.
Other vegetables are classified as non-starchy. Non-starchy vegetables tend to have a higher water content, and are lower in energy but often richer in vitamins and minerals.
Aim to make half your dinner vegetables and choose a range of different coloured vegetables. About one-quarter of the plate should be starchy foods for energy.
Phytonutrients are naturally occurring plant compounds. There are thousands of these different phytonutients in vegetables, usually in small amounts. Plants produce them for their own protection from insects or bacteria, as pigments for photosynthesis (energy production) and flavour. They are often responsible for the bright colours in fruits and vegetables, and research is showing that these colours may help reduce the risk of disease and promote health. Examples are lycopene in tomatoes and beta-carotene in carrots.
There is no single magic phytonutrient that can be isolated and turned into a daily tablet. The most protective effect comes from eating a wide variety of phytonutrients as they occur naturally in plant foods.
Phytonutrients may work in lots of different ways to protect against disease and promote health. Modes of action that are being investigated include anti-inflammatory activity, boosting the body's antioxidant defeces, modulating gut microflora, lowering cholesterol, fighting bacteria and supporting the body's immunity.
Main phytonutrients in vegetables
Unlike nutrients (vitamins and minerals) no recommended dietary intake levels have been established for phytonutrients. Health claims are not permitted and further human trials are required to substantiate the potential benefits suggested below.
Carbohydrates are a large group of organic compounds made by plants. Examples of carbohydrate are sugars, starch and cellulose and they provide our bodies with energy.
- Potatoes, yams and kumara contain carbohydrate, are called starchy vegetables and provide energy for our bodies.
- About a quarter of the plate should be made up of starchy foods, non starch vegetables should make up half the plate.
Vitamins and minerals
Vitamins and minerals are natural substances found in a wide range of foods and are essential to maintain a healthy body. Scientists have defined specific daily amounts necessary for good health.
Why they are important
Vitamin A stimulates new cell growth, keeps cells healthy and can help vision in dim light. Vitamin A is found in vegetables such as pumpkin, carrots, kumara, spinach and broccoli.
Vitamin B releases energy from food, and is good for the nervous system. Green vegetables contain Vitamin B.
Vitamin C is used in tissue repair, helps the immune system by fighting against infection and helps health in general. Vitamin C also helps iron in food to be absorbed. Capsicums and parsley are excellent sources of Vitamin C with significant amounts in broccoli, Brussels sprouts, cabbage, cauliflower, spinach, radishes, peas, beans, asparagus. Potatoes, turnips, tomatoes, kumara, spring onions, lettuce and leeks also contain Vitamin C.
Vitamin K helps blood clot. Turnips, broccoli, lettuce, cabbage, asparagus, watercress, peas and green beans have Vitamin K.
Calcium is necessary for healthy teeth, bones, hair and nails. Spinach, parsley, broccoli, celery, leeks, spring onions, cabbage and carrots contain calcium.
Potassium controls muscles and nerves and may be important in preventing high blood pressure. All vegetables contain potassium.
Iron is essential for red blood cells so that oxygen can be carried around the body. Eat vegetables that contain iron, with vegetables containing Vitamin C to help the iron be absorbed into the body. Spinach, silverbeet, parsley, leeks, broccoli and mushrooms are good sources of iron.
Avoid vitamin loss in vegetable preparation and cooking by:
Leaving the peel on as it contains vitamins as well as fibre.
Using a sharp knife. A blunt knife causes cell damage which leads to Vitamin C loss.
Cooking vegetables as soon as they are prepared. Don’t soak them in water as water-soluble vitamins (B and C) will be lost.
Using a small amount of water, or preferably, steam vegetables. Save the cooking water and use it in soups, stocks, gravies or enjoy as a drink.
Fibre keeps the digestive system healthy, helps keep a healthy body weight and decreases the risk of heart disease and cancer. Fibre has also been found to lower cholesterol levels by reducing the reabsorption of cholesterol produced by the body to help with the digestion of fat (Ötles & Ozgoz, 2014).
- All vegetables contain some fibre; some more than others. Vegetables that are high in fibre are broad beans, peas, spinach, watercress, green beans, sweet corn, silver beet, cabbage, butter beans, broccoli and Brussels sprouts.
- Carrots, parsnips, turnips, potatoes and kumara have a special type of fibre in their skins so scrub them instead of peeling them. Bake kumara and potatoes with the skin on.
- Prepare and cook vegetables the right way to preserve their valuable nutrients and fibre. Leave the peel on whenever possible.
- Vegetables that belong to the cabbage family (cabbage, cauliflower, turnips, swedes and Brussels sprouts) contain compounds that may be good at protecting against cancer.
Ötles, S., & Ozgoz, S. (2014). Health effects of dietary fiber. Acta Scientiarum Polonorum Technologia Alimentaria, 13(2), 191-202.