Keeping leafy greens high on your grocery list each week is a great habit to maintain. Besides adding color to your meals, these vegetables will boost your intake of an abundance of nutrients. Did you know that hiding behind the green color are yellow and orange pigments that represent a whole team of healthful nutrients?
Examples of leafy greens include a variety of dark lettuces, Swiss chard, spinach, kale (and some other cabbage family vegetables), arugula, collards, bok choy, watercress, and the greens of mustard, radishes, beets, turnips and other vegetables.
Each of these leafy greens contains various percentages of a number of healthful vitamins, minerals, and phytonutrients (other substances found in plants that contribute to optimal health). Many contain vitamins A, C, K, and several B vitamins (such as riboflavin, folate, and B6).
They may also contain manganese, iron, and calcium. Note that the iron and calcium in some greens (like spinach) are less available to the body due to the presence of compounds like oxalates. As with most vegetables, leafy greens are a source of fiber and potassium as well. By eating a variety of leafy greens you can take full advantage of their health benefits.
When it comes to the phytonutrients found in greens, many function as antioxidants. For example, the orange and yellow pigments representing the family “carotenoids” (such as beta carotene) are powerful antioxidants. These and other antioxidant substances found in greens protect many body tissues from damage.
Lutein is another example of a phytonutrient. It does most of its work in the eye, protecting it from ultraviolet radiation. Lutein is also used by the body to make another nutrient – zeaxanthin - that provides eye protection as well. Studies show that persons with higher intakes of greens containing lutein have a lower risk of getting age-related macular degeneration and cataracts.
Macular degeneration is the leading cause of blindness in older adults. Persons at greatest risk would be women (as they are less efficient at absorbing lutein), persons with blue eyes (the light color allows more light into the eyes), and those with a family history of age-related macular degeneration. An increased intake of leafy greens would be especially helpful to these individuals.
Lutein and zeaxanthin also appear to slow the problem of not being able to see as well in dim light and the age-related problem of not being able to see as well while driving at night. Foods that contain the highest amounts of lutein would be kale, spinach, collards, mustard greens, watercress, and parsley.
Leafy greens contain other substances like glutathione and alpha lipoic acid which also act as antioxidants to reduce the risk of cardiovascular problems. The many antioxidants found in leafy greens have also been studied for benefits to the brain. Higher intakes appear to slow age-related decline in memory and other mental skills.
In addition, a higher intake of leafy greens is also recommended because of their anticancer properties, to boost the immune system, and to slow the aging process in general. Just imagine – all these amazing benefits to health with almost no calories! What are you waiting for?
When preparing greens, rinse the leaves under cool water. You can store them with a damp paper towel in a plastic bag in the refrigerator for several days. Most can then be eaten raw or cooked. Cutting can release some of the nutrients so the body can better absorb them, as can adding a fat source (such as olive oil, avocado, nuts, seeds, egg yolk, etc.). Note that cooking can reduce the amounts of vitamin C and folate they contain. For some nutrients like beta carotene, however, cooking may actually increase availability.
The flavor of greens can be enhanced by adding cooked or raw members of the onion family (garlic, onions, shallots, scallions, etc.), herbs, vinegars, lemon juice, and various hot sauces. For greens with more significant stems, try chopping the stems and cooking them a little longer before adding the leaves.
Most greens can be added to soups, stews, egg dishes, a stir fry, smoothies, pesto, slaws, or salads. They can be used to make wraps or as a bed under the protein entrée (fish, poultry, eggs, seafood, lean meats). They can be used as a layer in a grain bowl or in a “lunch in a jar” salad. How about nibbling on some kale chips?
Note that vitamin K, which is found in leafy greens, can interfere with blood thinning medications. This does not mean that persons taking these medications need to avoid foods like leafy greens and miss out on all their health benefits. Instead, they need to be consistent with their intake so that the medication dose can be adjusted accordingly.
So, consider how you can consistently add more greens to your diet for both flavor and health benefits for only a few calories a day.
Pam Stuppy, MS, RD, CSSD, LD is a registered, licensed dietitian with nutrition counseling offices in York, ME and Portsmouth, NH. She is also the nutritionist for Phillips Exeter Academy, presents workshops nationally, and is Board Certified as a Specialist in Sports Dietetics. (See www.pamstuppynutrition.com for more nutrition information, some healthy cooking tips, and recipe ideas).