Kale is a member of the cabbage (Brassica) family of vegetables. It is considered to be one of the most nutritious foods per calorie and has often been labelled a superfood. It can be eaten raw, steamed, sauteed, boiled, or massaged in lemon juice. Kale makes a great addition to almost any diet for the substantial nutritional and health benefits it provides.

Nutrition Facts

The following nutrition information is provided by the USDA for 1 cup (16g) of raw kale.

Calories: 7.2

Fat: 0.3g

Sodium: 10.9mg

Carbohydrates: 0.9g

Fibre: 0.8g

Sugars: 0.16g

Protein: 0.6g

Carbs

Kale is low in calories and carbohydrates. One cup of raw kale contains only 7.2 calories and less than a gram of carbohydrate. Most of the carbohydrate comes from fibre.

The glycemic load of kale is estimated to be 3, making it a low-glycemic food. Glycemic load takes portion size into account when a food's impact on blood sugar is estimated.

Fats

There is almost no fat in kale. However, the way that you prepare this green superfood may change the nutrition it provides. If you cook kale in butter or oil or if you rub olive oil on kale leaves before roasting them or adding them to a salad, there will be additional fat.

Protein

Kale provides under 1 gram of protein per one-cup serving.

Vitamin and Minerals

Kale is an excellent source of vitamin K, vitamin A, and vitamin C. Kale is also a plant-based source of calcium (52mg), making it a particularly favourable vegetable in vegetarian and vegan meal plans. Kale also provides small amounts of manganese, copper, and vitamin B6.

Health Benefits of Kale

Kale is a green leafy vegetable that packs a huge nutrition punch. Comparable salad greens like romaine, iceberg lettuce, and mesclun or spring mixes do not provide the same nutrition. These are some of the health benefits associated with kale.

Healthy Weight Maintenance

Kale and other dark green vegetables provide great nutritional benefits for very few calories. The fibre and protein in kale can also help you to feel full and satisfied after eating. Studies have shown that diets that are higher in vegetables are sustainable and associated with greater weight loss.

Better Heart Health

Authors of a large research review published in a 2018 issue of the journal Nutrients compared different vegetables to evaluate their relative cardiovascular benefits. Kale was categorised with cruciferous vegetables along with broccoli, cauliflower, cabbage, and other veggies. Study authors concluded that consuming leafy green and cruciferous vegetables may provide the greatest cardiovascular health benefits.

Reduced Risk of Cancer

Kale is one of the cruciferous vegetables that has been shown to have anti-cancer properties. Kale contains glucosinolates—compounds that are being researched for their potential ability to manage certain health conditions in humans including certain types of cancer.

Better Bone Health

Vitamin K is important in bone health as well as clotting blood. Vitamin K deficiency is associated with osteoporosis. Studies have shown that vitamin K supplementation at high doses has a positive effect on the bone health of postmenopausal women.

While taking a supplement may be beneficial, including foods with vitamin K and other nutrients like calcium can help to make sure that you are not deficient in this important nutrient.

Cell Repair and Protection

The vitamin C in kale acts as an antioxidant in the body. Kale provides over 20% of your daily needs for vitamin C in a one-cup serving of the raw vegetable. Vitamin C is a water-soluble vitamin that is important in boosting immunity, repairing cells, and slowing down the aging process.

As an antioxidant, vitamin C is believed to prevent oxidative stress caused by exposure to free radicals in our environment (such as cigarette smoke) or free radicals made by the body. Experts recommend that we consume antioxidants in foods such as fruits and vegetables, rather than taking an antioxidant supplement.

Allergies

Kale allergies are rare. Kale is likely safe when consumed as a food, and possibly safe if used medicinally.

Adverse Effects

If you are someone who takes a blood thinner like warfarin it is important to be consistent with your vitamin K intake. Since kale is high in vitamin K, you should work with your healthcare provider or registered dietitian to make sure that your intake is consistent from day to day.

Varieties

When shopping for kale, you might notice the different types available. Many types of kale are green, but there are also red and purple varieties. Some of the most common types of kale for consumption include curly kale, ornamental kale, and dinosaur (Tuscan) kale. Each variety differs in texture, taste, and appearance.

Curly kale is usually deep green in colour with ruffled leaves and has a pungent, bitter, peppery flavour. Ornamental kale often referred to as salad savoy, can be either green, white, or purple. It has a more mellow flavour. Dinosaur kale has a sweeter taste and a more delicate texture than curly kale and is often a blue-green colour. Baby kale is readily available and has smaller softer leaves that many healthy eaters find more palatable than the larger leaves.

All kale is healthy, therefore it's hard to measure which type can be considered the healthiest. Each type contains a host of vitamins, minerals, and antioxidants. Purple varieties contain anthocyanins too, which have been linked with improving heart health.

If fresh kale is intimidating, you can either purchase kale that has already been cleaned and cut (this is good to make kale chips or easy to use to saute or throw in soups, stews, or chilli) or purchase frozen chopped kale. Many times, buying frozen vegetables is just as good, if not better, than buying fresh because the vegetables are picked at their peak freshness which makes them retain more vitamins and minerals.

When It’s Best

Kale is typically available all year long with its peak season during the winter months.

Purchase kale, whole, frozen, or cleaned, chopped and packaged. Look for kale that is crisp, with a greyish-green colour. Avoid kale that is wilted or limp.

Storage and Food Safety

You can store kale in the coldest part of your refrigerator for a few days. To prevent wilting, place kale in a plastic bag first and close it loosely. If you are unable to use it in a few days, you can cook it—boil or steam, and place it back in the refrigerator cooked.

Freeze it if you don't plan on using it for a while, it will keep in the freezer for about a month or two.

Always be sure to wash kale before using it because the large curly leaves often catch dirt. To wash fresh kale, place it in a bowl of cold water. Empty the bowl and repeat until all the dirt is cleared from the leaves.

How to Prepare

Kale has a bitter flavour and pairs well with rich, flavoured meats, such as pork. It can be steamed, sauteed, boiled, or chopped and used raw in salads. For a healthy chip alternative, try baking kale leaves to turn them into crispy kale chips.

You can also use kale in soups, stews, egg dishes, and chilli. It has a great way of enhancing the flavour of your meals and serves as a hearty, and healthy addition to your meal plan.

Note that some experts suggest steaming kale to maximise it's cholesterol-lowering effects because the fibre-related components in kale do a better job of binding together with bile acids in your digestive tract when they've been steamed.