This leafy green vegetable reached celebrity status around 2012. Since then it has been a staple on many plates thanks to a wide variety of health benefits and high concentrations of important nutrients.
Here’s your guide to the health benefits and nutrition of kale, as well as how to use it in your kitchen.
What is kale?
A member of the cabbage family, kale is a leafy green that’s related to Brussels sprouts, broccoli, and other cruciferous veggies.
Unlike cabbage, kale doesn’t grow in a round head, but rather in long stalks similar to romaine lettuce. Kale’s slightly bitter flavor puts it into the cooking greens group because it’s more nutrient-dense, more tender and less bitter when cooked.
Scientists disagree about when humans first tasted kale. But it is known that the ancient Greek cultivated leafy greens and early Roman manuscripts reference “brassica” which includes turnips, cabbage and kale-like plants.
The spread of kale occurred during the Middle Ages, when the Italians, Scots, and Russians all began to grow different varieties of kale.
Kale is actually a descendant of wild cabbage and is recorded to have grown and been consumed for at least 2,000 years, and potentially up to 4,000 years ago!
Where is kale grown?
Today, the majority of kale grown in the US comes from California farms, with Georgia, New Jersey, and Texas not far behind in production. As of 2012, there were 2,500 American kale farms. That’s up from about 100 farms in 2007.
When is kale in season?
Though it’s available throughout much of the year, kale is a cool-weather and frost-resistant plant grown mainly for autumn and winter harvests.
The low temperatures can actually make kale (and other cruciferous vegetables) convert starch molecules into sugar, making them sweeter and less bitter in flavor.
Its hardiness also makes it one of the few fresh greens available after most fresh veggies have become unavailable later in the season.
There are as many types of kale, ranging in color from deep greens and purples, to whites and pinks.
- Curly kale: the most commonly available type. It has bright green ruffled leaves that are quite hardy with a sharp peppery, pungent flavor. These leaves tend to be bitter and tough, so this variety of kale is best enjoyed cooked.
- Lacinato kale (aka Tuscan, dinosaur, black, or cavolo nero): this type of kale has narrow deep blue-green leaves that are long and dimpled (much like reptile skin) and it’s less bitter and more tender than most other varieties.
- Russian kale: with smooth, tender lacy-edged leaves and purple veins, Russian kale looks more like leaves from an oak tree. This variety becomes more colorful in colder weather and has a sweet and peppery flavor.
- Siberian kale: One of the most cold-tolerant varieties, Siberian kale has large gray-green ruffled leaves and is best eaten cooked.
- Redbor kale: has ruffled leaves like curly kale, but rather than green, Redbor kale ranges in color from deep reds to magentas and purples. It has a mild, crisp flavor and a texture that becomes softer and sweeter when cooked.
- Chinese kale (aka chinese broccoli, kailaan or Gai Lan): with glossy, blue-green leaves and crisp, thick stems, this type of kale can be substituted for regular broccoli in many recipes.
- Ornamental kale (aka salad savoy): picture what it would look like to combine regular kale with a head of cabbage and you’ve got yourself ornamental kale. It tastes similar to the other edible kale varieties (though is often quite bitter), but grows more like a flower and is a stunning addition to any garden.
Kale fun facts
Thomas Jefferson was a kale aficionado, growing and recording several varieties of kale in his garden at Monticello in the early 1800s.
National Kale Day is celebrated on the first Wednesday of October.
Kale is a nutrition superstar. It’s a good source of vitamins A, K, B6 and C, calcium, potassium, copper and manganese.
Kale is a member of the cruciferous vegetable family along with cauliflower, Brussels sprouts, cabbage, broccoli, collard greens, kohlrabi, rutabaga, turnips and bok choy.
Kale boasts quite a few health benefits thanks to high levels of antioxidants and many anti-inflammatory nutrients.
Kale contains good-for-eye-health nutrients such as the carotenoids lutein, zeaxanthin, and beta-carotene, which help reduce the risk of cataracts and can prevent harmful UV damage.
The potassium, calcium and magnesium in kale can also help reduce the risk of hypertension by counterbalancing the effects of sodium.
Kale’s high vitamin C content can help support immune health. Did you know kale has more vitamin C than an orange!?
It contains compounds that play a big role in reducing cholesterol. And the antioxidants in kale can help reduce oxidative stress, which left unchecked may contribute to heart disease and other inflammation-related conditions.
This all makes this green veggie quite the heart-healthy food!
Although kale is touted as one of the most nutrient-dense foods available, there are a few groups of people who should be careful with this assumption. People taking the blood thinner Coumadin/warfarin, or those who may develop oxalate containing kidney stones, should check with his/her doctor or dietitian before enjoying too much kale.
Also keep in mind, there is no one food that is miraculously better than everything else, even kale.
Though it's incredibly nutrient-dense, kale alone doesn't provide everything we need.
Incorporate kale, but don't forget - all foods give us something and all fruits and vegetables provide important vitamins and minerals.
Most grocery stores carry kale (generally the three most common varieties - curly, lacinato and redbor kale), but also look for it at farmer’s markets or try growing it for yourself!
Look for leaves that are deep green in color without yellowing or wilted leaves. Avoid wilted, browning or mushy kale.
As with other greens, the fresher the better - tough kale generally means it’ll be older and less flavorful.
Kale can be stored in the fridge for up to 5 days, but you may notice that the bitterness increases with age.
If you plan to use the kale in the next day or two, feel free to wash it ahead of time and store it in a towel in the fridge. But if it’s going to be several days before you end up using it, store it in an airtight container (unwashed) in the fridge.
You can still use wilted kale in just about any cooked dish, but save the fresh and perky leaves for your kale salads.
How to Prepare Kale
ALWAYS wash your kale. Aphids and cabbage worms love kale and other brassica veggies, so wash your kale thoroughly. And don’t freak out if you notice little buggers on your leaves. It’s normal and perfectly okay, just wash them off.
To wash: take each leaf individually and hold under running water. Move your fingers through each fold and crevice to remove any excess dirt or potential caterpillars (like I said, they really love kale!)
De-stem your kale: after washing each leaf, take both sides of the leaf and fold them together lengthwise. Rip the stem away from the leaf. You can also slice the leaves away from the stem with a knife.
Don’t toss those stems! Kale stems are edible and make a great addition to many recipes. Check out our kale stem section below for more ideas for using those kale stems.
Once the stem is removed, you can rip or cut the leaves into a variety of sizes. Use bigger pieces for kale chips, slightly smaller pieces for kale salad, or slice them into thin ribbons to add to a slaw or soup.
Next, massage your kale. I know it sounds ridiculous, but massaging kale makes it extra tender and is especially important if you’re planning to eat it raw (though I recommend massaging it no matter how you’re going to prepare it).
Add about a teaspoon of olive oil, lemon juice, or use both. Then using your hands, massage the kale for about a minute. I’m telling you, it makes all the difference between eating tough, fibrous greens or soft and tender leaves.
How to use kale
Kale can be eaten raw (lacinato or baby kale is best in salads) or it can be cooked. Kale holds its texture well in cooking and can be steamed, stir-fried, roasted, baked or blended.
- Use it in smoothies
- Let it wilt into soups
- Mash it with potatoes
- Turn it into pesto
- Add it to pizza for a crunchy topping
- Make a delicious kale salad like this Kale Fig Salad or Jicama Kale Salad
- Bake it for a delicious crunchy kale chip snack
- Use it in a Buddha Bowl
- Change it up with this Green Shakshuka instead of the traditional tomato-based variety
Kale is such a versatile veggie!
Using kale stems
Use your kale stems. They’re totally edible, but tend to be somewhat tough and fibrous. I like my kale stems thinly sliced and roasted to perfection. And they make a great addition to eggs for breakfast!
- Cut stems into small pieces and add to a stir-fry or frittata or shakshuka
- Roast them and add to your next Buddha Bowl
- Add diced stems to soups
- Use both the leaves and stems on your next pizza
- Use them to make a vegetable stock
Kale is a healthy and delicious cruciferous vegetable that can be incorporated into your culinary creations in so many ways. I would love to hear YOUR favorite way to enjoy kale.
Leave a comment below and let me know your favorite way to incorporate them into your meals.
Also check out our other Superfood Spotlights!