Kale 101: Why This Leafy Vegetable Is So Popular

Kale is a very popular, well-loved superfood. But why is kale good for you—and how can you integrate it in your diet? Here’s all you need to know about eating kale!

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Kale has been around forever, but it’s been particularly trendy for the past couple of years. Many people love kale because it’s tasty, nutritious, and versatile. It’s packed with vitamins and minerals and it’s low in calories, which means it’s a fantastic addition to nearly every diet. Admittedly, I was a little late to the kale party. I assumed it was exactly like spinach, both in taste and nutritional value, so I didn’t see a need to add another vegetable to my diet. It turns out that kale doesn’t quite taste the same as spinach—in fact, I personally prefer the taste of kale to spinach. More importantly, kale often beats spinach when it comes to nutritional content. The hype around kale is truly well deserved. If you’re wondering why kale is good for you, read on to learn more about the health benefits of consuming this leafy green.

The Nutritional Benefits of Kale

Kale is often considered a “superfood” because it’s abundant in vitamins and minerals, says Michelle Routhenstein, who is a registered dietitian, nutritionist, and the owner of Entirely Nourished. In one cup of raw kale, you’ll find vitamins and minerals such as:

  • Vitamin K, which is an essential nutrient for blood clotting. One cup of kale contains six times the recommended daily allowance (RDA) of vitamin K.
  • Vitamin A, which promotes good vision, healthy skin, and a strong immune system.
  • Vitamin C, which is an excellent antioxidant. Again, one cup of raw kale contains more than the RDA, which means kale’s an excellent source of vitamin C.
  • Vitamin B6, another essential vitamin. A deficit of vitamin B6 is associated with a weakened immune system, dermatitis, depression, and anemia.
  • Manganese, which is involved in bone formation and in how our bodies metabolize lipids, carbohydrates, and amino acids.
  • Copper helps the body absorb iron—and along with iron aids the body in forming red blood cells.

Kale also contains a number of antioxidants, including vitamin C and flavonoids like quercetin and kaempferol. Antioxidants are believed to prevent certain diseases associated with aging, including cancer. Generally, the nutrients found in cruciferous vegetables like kale are associated with cancer prevention, but these studies should be taken with a grain of salt. While research suggest cruciferous vegetables can prevent cancer in certain organs, more studies are needed to figure out why this is so. Registered dietician and nutritionist Vanessa Rissetto says that kale is also great because it contains a lot of fiber. “One cup of kale has only 36 calories, 5 grams of fiber, and 0 grams of fat,” she says. “It’s great for aiding in digestion and elimination with its high fiber content.” Fiber helps you feel fuller for longer, so it’s an excellent addition to your breakfast if you feel yourself getting hungry before lunch. Another advantage of eating kale is that it’s a low-FODMAP food, says Routhenstein. People with irritable bowel syndrome (IBS) are often advised to eat low-FODMAP foods, which are less likely to aggravate their symptoms. “A 1-cup serving of chopped kale is low in FODMAPs and should be tolerated by most people with IBS,” Routhenstein says. “I would not recommend avoiding kale if you have IBS, unless your body is sensitive to it.”

Should I eat raw kale, or should I cook it?

Kale can be consumed in a cooked form—as kale chips and in frittatas, sautéed meals, and more—or raw in salads and smoothies. But is it better to eat raw kale or cooked kale? It’s important to note that the above nutritional data is based on raw kale. Cooking kale can change the nutrient makeup, according to Rissetto. “Any time you heat vegetables—for example, if you boil them—you are at risk of losing nutrients,” says Rissetto. If you have hypothyroidism, you should avoid eating raw kale, Routhenstein says. For everyone else, she suggests eating raw kale in moderation. “Raw kale is a goitrogenic vegetable, which inhibits the uptake of iodine by the thyroid gland. However, studies have shown that you need to eat excessive quantities for this to occur—about 15 cups,” she says. There is some research that shows that cooking kale negates this effect, though. So for most people it’s fine to indulge in sautéed, roasted, or boiled kale!

Different Kinds of Kale

You’ll find that there are a number of different types of kale out there. Routhenstein says that there are about 10 kale varieties in total, with four that are the most popular and easiest to find: curly kale, Red Russian kale, Redbor kale, and lacinato kale (also known as Tuscan or dinosaur kale). They all taste slightly different, so if you find yourself disliking one variety, try the others! “While the textures and taste of the kale may be different, which may affect how you use each variety, the nutritional profile is pretty much the same,” says Routhenstein. “Choose the variety you enjoy most!”

Finding and Storing Kale

You can find kale at many grocery stores and farmers markets—but how can you tell if it’s fresh? Ideally, it should be bright green, says Rissetto. “The best way to tell if your kale is going bad is to look at the leaves,” Rissetto explains. “When kale begins to age, it will lose its bright green color and begin turning a yellowish color.” Once you find kale, it’s important to store it properly to keep it from wilting too fast. “Refrigerating kale appropriately can slow the breakdown of vitamins that are highly susceptible to heat,” Routhenstein notes. “To store, keep unwashed kale in a storage bag and remove as much of the air as possible.” Routhenstein advises that you use it within five days of storing it in the refrigerator. “As time progresses the kale becomes more wilted and bitter in flavor,” she says.

Who shouldn’t eat kale?

Kale has some impressive benefits—but is there anyone who shouldn’t eat it? As mentioned earlier, kale is very high in vitamin K, which is involved in ensuring that your blood clots properly. People who take certain blood thinners are advised to eat a consistent amount of vitamin K, says Routhenstein. “If someone is taking warfarin or Coumadin, they should consume the same amount of kale at the same time each day so their medication can be dosed appropriately,” she explains. “For many, eating the same amount of kale at the same time of day every day may be challenging so they may opt to avoid it altogether.” If you’re taking a blood-thinning medication, speak to your doctor before indulging in kale.

How to Incorporate Kale in Your Diet

There are a variety of ways to enjoy kale. If you’re not too sure where to start, Rissetto and Routhenstein have shared a few of their favorite kale dishes.

Kale Salad

“I like to make my salads with kale—I soft boil two eggs, add shaved parmesan, ¼ of an avocado, and use lime juice as my dressing,” says Rissetto. “The citrus has a great flavor but it also helps to break the kale down and make it not so tough.” Routhenstein suggests you massage the destemmed part of the kale with a combination of extra virgin olive oil, lemon juice, and tahini sauce to break up the roughage.

Kale Soup

Do you want a warming, tasty meal that’s also full of vitamins? Try a hearty bowl of kale soup. Routhenstein suggests adding finely chopped kale to soup for a nutritional boost. “It pairs well with root vegetable–based soups,” she says. “Think: autumn squash, sweet potato, and butternut squash.”

Kale Chips

Kale chips are a delicious, easy snack. “My kids love to make kale chips,” says Rissetto. “We spray the kale with olive oil and bake in the oven for 20 minutes.” The chips can be sprinkled with spices for taste.

Kale Smoothies

Although some suggest adding raw kale to smoothies, others might want to avoid raw kale for the reasons mentioned earlier. But it’s totally possible to add cooked kale to your smoothies, says Routhenstein. “Boil a handful of kale for 5 to 7 minutes and toss it into a smoothie for a boost in nutrition,” she says. “It’s surprisingly mild in flavor!” Beyond that, Routhenstein suggests you add kale to a frittata dish, swap your burger bun for blanched lacinato kale, or sauté your kale with avocado oil and mushrooms. Once you start cooking with kale, you can decide whether you want to experiment with different recipes and flavor combinations. Kale is a delicious vegetable that’s packed with nutrients, which makes it a fantastic addition to your diet. Don’t be afraid to experiment with new kale-based dishes or to make kale a part of your favorite meals!