If you have not tried kale yet, now may be the time. This super green is packed to the max with nutrition that puts it high on the list of the world's healthiest foods.
Even spinach cannot come close in comparison to the number of nutrients that kale provides. Including kale in your diet provides nutrients that support healthy skin, hair and bones, as well as healthy digestion and a reduced risk of heart disease.
Other possible health benefits of kale include improving blood glucose control in diabetics, lowering the risk of cancer, lowering blood pressure and lowering the risk of developing asthma.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods, written and reviewed by our qualified nutritionist. It provides a nutritional breakdown of kale and an in-depth look at its possible health benefits, how to incorporate more kale into your diet and any potential health risks associated with its consumption.
Possible health benefits of consuming kale
- Heart disease
- Bone health
- Health skin and hair
Kale's nutritional breakdown
Kale is a leafy green cruciferous vegetable that is chock-full of essential vitamins C and K, vitamin A in the form of beta-carotene, and minerals like copper, potassium, iron, manganese and phosphorus. A cup of chopped fresh kale has only about 8 calories but contains 24 mg of calcium, 79 mg of potassium, and 17 mcg of folate.
One cup of cooked kale has over 1000% more vitamin C than a cup of cooked spinach and, unlike spinach, kale's oxalate content is very low which means that the calcium and iron in kale are highly absorbable in the human digestive system.
How to incorporate more kale into your diet
A member of the mustard family (Brassicaceae), kale has a spicier and more pronounced flavor than lettuce. It is also heartier and crisp with a hint of earthiness. Different types of kale have slightly different flavor profiles and nutrient profiles, and younger leaves and summer leaves tend to be less bitter and fibrous.
Curly kale is the most commonly available variety and is usually bright or dark green or purple in color. It has tight ruffled leaves that are easy to tear. To remove the leaves from the fibrous stalk, simply run your hand down the stalk in the direction of growth.
Lacinato kale, or dinosaur kale (so-called because of its scaly texture), is a dark blue-green variety that is firmer and more robust than curly kale. These leaves are generally longer and flat and maintain their texture after cooking. Not so bitter as curly kale, dinosaur kale is ideal for making kale chips.
Red Russian kale is a flat leaf variety that looks a little like oak leaves. The leaves have slightly purple stalks and a slight red tinge to the leaves themselves. The stalks are very fibrous and are not usually eaten as they can be rather difficult to chew and swallow. The leaves of red Russian kale are sweeter and more delicate than other types, with a hint of pepper and lemon, almost like sorrel. They are ideal for including in salads, sandwiches, juices and for adding as a garnish.
Kale grows well in the colder winter months, so can be a great addition to your fruit and vegetable intake when other produce is not as readily available. Winter kale is usually better cooked as colder weather can turn the sugars in kale into starch, and increase the bitterness and fiber content of the leaves.
If using kale raw in salads, it is a good idea to massage the kale (scrunch it briefly in your hands) to begin the breakdown of the cellulose in the leaves, thereby helping to release the nutrients for easier absorption.
Kale can be enjoyed raw in salads or on sandwiches or wraps, braised, boiled, sauted or added to soups and casseroles.
Saut fresh garlic and onions in extra-virgin olive oil until soft. Add kale and continue to saut until desired tenderness.
Kale chips: Remove the ribs from the kale and toss in extra-virgin olive oil or lightly spray and sprinkle with your choice or a combination of cumin, curry powder, chili powder, roasted red pepper flakes or garlic powder. Bake at 275 degrees Fahrenheit for 15-30 minutes to desired crispness.
In a food processor or a high-speed blender, add a handful of kale to your favorite smoothie for a nutrient blast without a big change in flavor.
Potential health risks of consuming kale
Beta-blockers, a type of medication most commonly prescribed for heart disease, can cause potassium levels to increase in the blood. High potassium foods such as bananas and cooked kale should be consumed in moderation when taking beta-blockers.
Important note: consuming too much potassium can be harmful for those whose kidneys are not fully functional. If your kidneys are unable to emove excess potassium from the blood, it could be fatal.
A cup of cooked kale provides 1062.1 mcg of vitamin K, which could interfere with the activity of blood thinners such as Warfarin. Speak to your doctor about foods to avoid when taking these medications.