Collard Greens: Health Benefits Beyond Vitamin K and Carotenoids
Not only do they make a delicious side dish when sautéed, collard greens are also good for you. Many of the health benefits of collard greens are derived from the their high vitamin K content, but also other nutrients – such as carotenoids and calcium – contribute to the health boosting properties of this unsung superfood. Here's a lowdown of the most interesting nutritional benefits of collard greens:
Collard Greens Contain Tons of Vitamin K
Collard greens are supercharged with vitamin K, although they don't quite beat the superfood kale. According to USDA's Nutrition Facts data, 1 ounce of cooked and drained collard greens contain a whopping 154% of the Daily Value for vitamin K, and raw collard greens contain even more! (One ounce of cooked kale provides 286% of the Daily Value for vitamin K.) Vitamin K plays a major role in blood clotting, but recent research suggests that this often-overlooked vitamin may also play a key role in maintaining a healthy cardiovascular system.
Tip: Looking for natural ways to reduce your risk of cardiovascular diseases? Check out HealWithFood.org's overview of the Best Vitamins for Cardiovascular Health.
Eye Health Protecting Qualities Proven by Studies
Collard greens are packed with pro-vitamin A (in the form of carotenoids), with one ounce of cooked and drained collard greens delivering a whopping 45% of the Daily Value for pro-vitamin A. Carotenoids are involved in numerous bodily functions, but they are probably best known for their ability to protect eye health. A case-control study published in the November 1994 issue of The Journal of the American Medical Association found that those in the highest quintile of carotenoid intake had a 43% lower risk for age-related macular degeneration, a leading cause of blindness in adults, compared with those in the lowest quintile. This study also found that found that people who frequently ate collard greens or spinach had a particularly low risk of developing age-related macular degeneration.
Tip: Drizzle some healthy oil, such as avocado oil, on your collard greens before eating them. Carotenoids are fat-soluble, meaning that they can only be absorbed if the meal contains some fat.
Calcium and Vitamin K for Healthy Bones
Collard greens provide a good amount of calcium which is a key component of bones. Furthermore, the calcium found in collard greens has been shown to be highly bioavailable. A study published in the Journal of Food Composition and Analysis in 2004 reported that collard greens – along with kale, celery, Chinese cabbage, pak-chee-lao (Anethum graveolens L.), and soybean sprouts – showed highest calcium bioavailability among the tested plant-based foods.
The vitamin K in collard greens may also add to the benefits collard greens can offer to your bones. Scientific evidence suggests that vitamin K can increase bone mineral density as well as reduce fracture rates in osteoporotic people.
Tip: Human intervention studies show that vitamins K and D works synergistically on bone density. To maximize the bone health boosting benefits of collard greens, eat your collard greens with foods that contain vitamin D, such as fatty fish.
Proven Cholesterol-Lowering Ability
Collard greens are right there on top of the list of cruciferous (Brassica) foods with cholesterol-lowering potential. An in vitro study published in the June 2008 edition of the journal Nutrition Research found that steamed collard greens, along with steamed kale and mustard greens, had the strongest bile acid binding capacity – indicative of strong cholesterol-lowering potential – among the tested cruciferous vegetables. Steamed collard greens were found to have even more bile acid binding capacity than steamed broccoli, Brussels sprouts, spinach, and cabbage.
How to Eat Collard Greens
Collard greens are a relatively mild-tasting member of the cruciferous family that includes other highly nutritious vegetables like kale, mustard greens, and broccoli. The sturdy leaves of the collard plant make a nice vegetarian side dish when simmered with chopped onion, garlic, and olive oil for about 35 minutes. They also make a wonderful substitute for cabbage or grape leaves in vegetable rolls.