Skip the iceberg lettuce and go for something a bit darker in color, such as kale, the next time you decide to eat a green leafy vegetable. A cup of raw kale contains only 33 calories but provides 10 percent of the daily value for calcium, 134 percent of the DV for vitamins A and C and 590 percent of the DV for vitamin K. However, how you prepare your kale can affect the amount of nutrients you get from this nutrient-dense vegetable.
With raw kale, you don't have to worry about losing any vitamin C during the preparation process. Both heat and water contribute to vitamin C losses. Remove the tough ribs from the kale and either chop your kale leaves into thin strips or massage them with a little oil until the kale turns bright green and softens up a bit, then add your favorite salad fixings.
Steamed or Microwaved Kale
While raw kale is nutritious, if you steam cook your kale it will better bind with substances in your body called bile acids, helping you lower your cholesterol and your risk for heart disease and cancer, according to a study published in "Nutrition Research" in June 2008. Microwaving kale without adding water also has a similar effect, according to another study published in "Vegetos- An International Journal of Plant Research" in 2012. Both of these methods also help maintain the vitamin C in kale, which can leach out into cooking water if you boil it.
Other Healthy Cooking Methods
For a healthy alternative to potato chips, toss kale with a small amount of oil and salt or other seasoning and bake it in the oven until crisp, which only takes a few minutes. You can also add kale to soups when they are almost done cooking to boost the nutrient content. Another option is to saute kale in a small amount of oil for just a minute or two. Kale pairs well with foods including garlic, white beans, cranberries, avocado, blue cheese and nuts.
Adding Fat to Your Meal
However you decide to prepare your kale, make sure that you include at least a little bit of fat somewhere in the same meal. Some of the nutrients in kale, including beta-carotene and vitamins A and K, are fat-soluble, so you can't absorb them if you don't consume at least a little fat around the same time. This doesn't mean you should drown your kale in oil, since fat is high in calories and not healthy in large amounts.
- USDA Nutrient Data Laboratory: Kale, Raw
- Nutrition Research: Steam Cooking Significantly Improves in Vitro Bile Acid Binding of Collard Greens, Kale, Mustard Greens, Broccoli, Green Bell Pepper, and Cabbage
- Epicurious: How To Cook With Kale
- Vegetos- An International Journal of Plant Research: In vitro Bile Acid Binding of Kale, Mustard greens, Broccoli, Cabbage and Green Bell Pepper Improves with Microwave Cooking
- U.S. Food and Drug Administration: Calculate the Percent Daily Value for the Appropriate Nutrients
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.