Kale has become the darling vegetable of the nutrition world. It is part of the Brassica group, which includes other cruciferous vegetables such as cabbages, cauliflower, Brussels sprouts, and broccoli.
When you see some of the stats on the kate, it is very easy to see why it has become so popular. It provides a nutrient-dense hit every time. It is packed with beneficial fiber, vitamin C, vitamin A, vitamin K, and magnesium.
Kale is also a rich source of antioxidant polyphenols (at least 45 different polyphenols), ranking higher than other Brassica vegetables. Polyphenols different protective properties are known for their protection against the effects of aging and also oxidative stress.
Anti-aging and antioxidant
Kale may contain up to 200% of your daily vitamin C requirements. This makes it a powerful, natural antioxidant. Vitamin C is one of the main antioxidants that the body has and it is most concentrated in the adrenals. Vitamin C as an antioxidant also reduces the risk of atherosclerosis and other conditions related to oxidative damage.
Vitamin C reduces free radical damage caused by exposure to pollutants and helps to rejuvenate photo-damaged skin (excess sun exposure). It is an essential component in the production and maintenance of collagen and elastin, so it supports smooth skin.
It needs to be noted, however, that the levels of vitamin C and other nutrients in kale depends on the species, maturity, weather conditions and condition of the soil in which it is grown.
Kale and eye health
Kale contains the carotenoids lutein and zeaxanthin, along with fantastic levels of beta-carotene which are all essential for good eye health and the prevention of eye conditions such as cataracts and macular degeneration.
Kale and preventative health
Kale, along with other cruciferous family members, contains glucosinolates which are then converted to compounds such as isothiocyanates, thiocyanates and indoles. Regular consumption of kale and other cruciferous vegetables, to obtain adequate levels glucosinolates is associated with a reduced incidence of cancer.
These same cruciferous vegetables such as kale can also interfere with thyroid health due to the glucosinolate compounds in these foods. These foods are also known as goitrogens and can interfere with iodine metabolism. They do this by reducing iodine uptake and blocking the activity of thyroid peroxidase (TPO), which is needed for the conversion of T4 to active T3 in the thyroid. Care should be taken with people who may suffer from iodine deficiency or are suffering from any potential thyroid related conditions.
Kale also contains oxalates which can interfere with the absorption of calcium and may be implicated in the formation of kidney stones. If you are at risk of kidney stones, consult with your primary healthcare professional.
Kale is a good source of vitamin K – which needs to be monitored with people on blood thinning medications such as warfarin. We would advise that if you are someone on these sort of medication, seek out the advice of your primary health care professional before adding any new food rich in vitamin K to your diet.
Types of kale
1. Curly kale – probably the most common type of kale that can be found in most supermarkets and greengrocers. It has a pungent, almost peppery flavor that is very pleasant to the palate but if you prefer less bitterness, look for younger kale as leaves have a milder taste.
2. Lacinto kale – another popular type of kale also known as Tuscan kale or Tuscan cabbage (cavolo nero) or Dinosaur kale. Its leaves are narrow, dark green and wrinkly attached to a hard stem that should ideally be removed. It’s flavorsome and mildly astringent.
3. Redbor kale – this is a very pretty looking kale with ruffled leaves ranging from deep red to purple color, sometimes with some shades of green. As well as cooking, Redbor kale is also used for its ornamental qualities in the garden and for garnishes.
4. Russian (Siberian) kale – this type of kale is harder to find but is equally beneficial and delicious, with flat, fringed leaves that look like large rocket/arugula leaves and range from green to red/purple shades. It’s sweet and mild with traces of pepper and can be cooked in the same way as the other types of kale.
What is the difference between green kale and red kale?
The primary difference between the two is in the way they taste. Red Russian kale is said to have a much sweeter and delicate flavor compared to green kale. Therefore, sometimes it’s an easier option to get your taste buds introduced.
Red kale nutrition is almost identical and both are great options for a nutrient-dense green leafy vegetable, packed with vitamin K, vitamin C and other antioxidants.
Where to get kale
Fresh: From farmers’ markets or supermarkets and – when possible – buy organic and local. Be on the lookout for the nice dark, green-colored leaves and moist (not hard and woody) stems. Kale is also relatively easy to grow if you have a little patch of soil.
Supplement form: You can get kale in a powdered capsule form, usually in combination with other dried greens. As always, we do not recommend you start any new supplement without consulting your primary health care professional first.
How to use kale
Store kale in a plastic storage bag, removing as much air as possible. Keep unwashed kale in the refrigerator for about 5-7 days.
Kale can be eaten raw or lightly cooked as this helps to preserve the antioxidants, polyphenols and beta-carotene content.
It’s great in soups, stews, stir-fries, and salads.
You can make green smoothies, add it to a fresh salad raw or lightly sautéed with some butter, onion, and garlic.
Making kale chips by dehydrating the kale leaves is a great (and very moreish) way to eat kale. A dehydrator can be a great kitchen investment for getting in more fruits and veggies or preserving the harvest.
It is always usually best to remove the thick center stem, as this can be too tough to be enjoyable to eat.
To further enhance kale’s phytonutrient content, sprinkle the leaves with lemon juice before cooking and let sit for a few minutes.