Vary veggies and prep methods for ultimate health
With food growing season coming to an end, it’s important to make sure you are still getting the vitamins, minerals and disease preventing compounds you need to stay healthy.
For the most part, vegetables begin to lose nutrients once they are harvested. However, a recent study showed that green leafy vegetables that are stored under full spectrum light, such as grocery store fluorescents, are more nutritious than those stored in the dark. That’s because the vitamins are essential for photosynthesis, which continues to occur as long as the plant is green.
Many believe that raw vegetables provide ultimate nutrition, being much healthier than cooked. A review of the literature reveals that it’s not that simple.
We know that heat does kill vitamin C. One researcher found that vitamin C levels declined by 10 percent in tomatoes cooked for two minutes, and 29 percent in tomatoes that were cooked for half an hour. That’s because vitamin C is highly unstable. It is easily degraded through oxidation, exposure to heat and it dissolves in water. However, it’s readily available in uncooked citrus. Just 4 ounces of orange juice contains more than 100 percent of the recommended daily value for vitamin C.
Some raw vegetables, such as broccoli, have been shown to contain an enzyme called myrosinase, which enables the compound sulforaphane to be produced. This compound might block the proliferation of and kill precancerous cells.
But carotenoids, the pigments that give plants their orange, yellow, or red color, are more easily absorbed when vegetables are cooked and served with fat. When the plant is cooked, it breaks down the cell walls and membranes, which helps release the carotenoids. They are fat soluble, so some fat needs to be present for the body to absorb them.
One type of carotenoid, lycopene, is a red pigment found predominantly in tomatoes, watermelon, red bell pepper and papaya. Several studies conducted in recent years have linked high intake of lycopene with a lower risk of cancer and heart attacks. It may be an even more potent antioxidant than vitamin C.
The body converts beta-carotene, found in carrots and sweet potatoes, into vitamin A, which plays an important role in vision, reproduction, bone growth and regulating the immune system.
One report showed that boiling and steaming better preserves antioxidants, particularly carotenoid, in carrots, zucchini and broccoli, than frying. Deep fried foods are a source of free radicals, caused by oil being continuously oxidized when it is heated at high temperatures. These radicals, which are highly reactive because they have at least one unpaired electron, can injure cells in the body. Deep-fat frying does not add health promoting benefits to vegetables.
Comparing the healthfulness of raw and cooked food is complicated, and there are still many mysteries surrounding how the different molecules in plants interact with the human body. The bottom line is to eat your veggies and fruits, prepared the way you enjoy.
The more variety, the better.
This recipe is one of my favorite ways to eat spinach.
Creamy Spinach and Leeks
3 tablespoons butter
1 clove minced garlic
3 tablespoons AP or whole wheat flour
½ teaspoon salt
¼ teaspoon pepper
1/8 teaspoon ground nutmeg
1 pound spinach
½ cup milk
¼ cup parmesan cheese
Trim dark green ends from leeks. Under running water, remove dirt from inside of leeks. Pat dry and chop coarsely. In a large skillet, melt butter over medium low heat. Add leeks and garlic and cook until tender, around 10 minutes. Coarsely chop spinach. In a small bowl combine flour, salt, pepper and nutmeg. Add spinach to skillet and stir. Add flour mixture and stir. Add milk and cook until the sauce thickens. Stir in parmesan cheese and serve.
Margie Mansure, M.S., R.D,. is a registered dietitian and nutritionist and extension agent with the N.C. Cooperative Extension. She offers personalized classes to improve the health of citizens in Watauga County through worksites, schools and community groups. For more information, email firstname.lastname@example.org or call (828) 264-3061.