Fruits and vegetables are an important part of a healthy diet. The vitamins, minerals, phytochemicals and antioxidants found in them can reduce the risk of cancer, improve signs of aging, promote bone health, and boost memory.
Surveys show many of us fall short of what we need, mainly because we don’t eat enough fruits and vegetables. We also could be wasting a lot of nutrients if we’re preparing our foods the wrong way. When cooked improperly, most minerals and some vitamins can be lost. Water-soluble vitamins such as B vitamins and vitamin C can be leached into cooking water and discarded.
Fruits and vegetables can be enjoyed in their raw form, cooked, or canned. Some say freshest is the best, such as raw vegetables. But that’s not always the case. Cooking with low heat can in fact improve the availability of some nutrients.
“When you cook carrots, carotene becomes more available to the body so you get more of it absorbed in your blood. When you cook tomatoes, the red pigment, the lycopene also becomes more available to your body….and Goitrogens are known as anti-nutrients, which can actually reduce the levels of thyroid hormone in the body, so if you have thyroid problems, sometimes it’s better to cook the broccoli to deactivate the compound ” (www.citytv.com)
Boiling is an especially destructive cooking method. A 2007 British study showed that cruciferous vegetables (a group that includes broccoli, brussels sprouts, and cabbage) had almost 90 percent of their cancer-fighting antioxidants removed after boiling, but not much lost after steaming or stir-frying. The same effect was observed with flavonoids (phytonutrients that prevent cancer and heart disease), and glucosinolates (plant compounds that may help prevent cancer). Zucchini, beans, and carrots retain much higher amounts when cooked in a little water versus being cooked in large amounts of water.
Microwaving, which was long thought to be fairly easy on vegetables, has been found to also remove some of their most valuable nutrients. Super-healthy broccoli lost 74 to 97 percent of its antioxidants (including vitamin E and beta carotene) when immersed in water and then zapped, according to a 2007 Portuguese study.
To preserve vitamins in produce try the following:
- Cook foods in the shortest amount of time possible. Vegetables should be tender-crisp, not soft and limp.
- Steam, and/or stir-fry vegetables. These cooking methods are quick which helps retain vitamins.
- Cook vegetables in a covered pot to prevent nutrients from escaping in the steam.
- Cook vegetables whole and unpeeled whenever possible.
- Cut vegetables with long cooking times into large pieces. With less surfaces exposed, fewer vitamins are lost.
- Leave edible skins on vegetables when possible. Many vitamins and minerals are found in the outer leaves, skin, and area just below the skin.
- Cook foods as close to serving time as possible.
- Instead of wasting nutrients that have leached away during cooking, save the water and use in soups, stews, gravies, and sauces.
Another factor often overlooked are that plant enzymes are easily destroyed by heat. We need enzymes for life and we don’t get enough as many people eat too many processed foods devoid of them. Adding a destructive cooking method to your plant foods only adds to the burden of digestion.
Overall, the five big factors which destroy nutrients most are:
1. High temperatures
2. Prolonged cooking times
3. Alkalis such as baking soda and hard water
4. Soaking vegetables in water before cooking
5. Oxygen.
Source: University of Kentucky – College of Agriculture/Cooperative Extension Service)
The most important thing is to focus on is to get more, and a better variety of these foods. So do get the recommended 5 to 10 servings of fruits and vegetables each day, because most of us don’t even get the minimum.
