What It Is, Nutrition and Benefits

Kale may not be everyone’s first choice at the dinner table, but don’t underestimate this veggie. Packed with disease-fighting nutrients, kale deserves a starring role on your plate.

“Kale is more than just a healthy leafy green,” says registered dietitian Michela Palma, RD, LD. “It has an impressive list of nutrients that provide many disease-fighting benefits. And it’s easier to incorporate into your diet than you may think.”

There are lots of ways to prepare and eat this nutrient-packed vegetable — you can probably find one that suits your taste buds.

What is kale?

Kale is a fibrous, leafy green cruciferous vegetable. It’s part of the Brassicaceae family, along with other greens like collards, broccoli, Brussels sprouts, cabbage and cauliflower.

Nutrients in kale may benefit your health in several ways. They can help fight cancer, inflammation, boost eye health, remove toxins and enhance digestion.

“There are many varieties of kale,” adds Palma. Different types of kale offer varying textures and slight differences in flavor. Types of kale you’re likely to find include:

• Beira kale has broad, wavy green leaves.
• Darkibor kale is green with curly-edged leaves.
• Lacinato kale — also known as Tuscan or dino kale — has dark green, narrow and relatively flat leaves.
• Redbor kale has purplish, tightly curled leaves with frilly edges and purple stems.

Is kale healthy?

Kale is low in calories, high in fiber and full of beneficial nutrients. One cup of raw kale provides:

• 7.4 calories
• 0.9 grams of carbohydrates
• 0.3 grams of fat
• 0.9 grams of fiber
• 0.6 grams of protein
• 11 milligrams of sodium
• 0.2 grams of sugar

One cup of kale also contains:

• 82 micrograms of vitamin K (68% of your daily value or DV)
• 20 milligrams of vitamin C (22% DV)

Is kale a superfood? “Yes, we consider dark, leafy greens like kale to be superfoods due to their high antioxidant, fiber, mineral and vitamin content,” confirms Palma. “Superfoods are exceptionally dense in health-promoting nutrients.”

Palma shares some of the top health benefits of kale.

1. Potential to remove toxins

“Research suggests that phytonutrients found in kale and other Brassicas may absorb and help eliminate toxins in the digestive tract,” says Palma. In the study, molecules in kale absorbed several different mycotoxins — harmful waste produced by fungi that often contaminate foods.

Mycotoxins can cause liver damage and other health issues. The research results are promising, but researchers need to do more studies to fully understand kale’s detox power.

2. Supports eye health

Kale contains potent antioxidants that are especially good for your eyes and vision:

• Beta-carotene reduces your risk of cataracts and age-related macular degeneration (AMD), two conditions that affect vision.
• Lutein and zeaxanthin protect against AMD by filtering out harmful blue light, according to research.
• Vitamin C combats harmful free radicals to help prevent damage to eye cells from oxidative stress.
• Vitamin E lowers the risk of cataracts and AMD and protects fatty acid molecules in your retina.

3. Lowers cancer risk

No single food can prevent cancer. But a diet high in cruciferous veggies like kale may help lower your risk of:

• Breast cancer
• Colorectal cancer
• Lung cancer
• Prostate cancer

According to the National Cancer Institute, unique molecules in kale (including glucosinolates, indoles and sulforaphane) may:

• Neutralize carcinogens (cancer-causing molecules)
• Protect cells from DNA damage that can lead to cancer cell growth
• Support the breakdown of cancer cells before they can multiply and spread

Palma notes that many of these studies were performed on cells or models. “We need human studies to confirm that kale and other cruciferous vegetables have these anticancer effects in people,” she says.

4. Benefits digestion

Your gut microbiome is made up of the beneficial bacteria and microbes that help you digest food. A healthy microbiome also benefits your immune system, fights inflammation and boosts mental health.

“Kale provides prebiotics — food for the beneficial bacteria in your digestive system,” shares Palma. According to research, eating kale can also help relieve constipation.

5. Combats inflammation

Inflammation is a natural response to illnesses and injuries. But long-term inflammation contributes to many chronic diseases and cancers. “Kale provides a unique mix of several antioxidants and other nutrients that work to stop inflammation,” says Palma.

Kale contains:

• Isothiocyanates: Molecules that have powerful anti-inflammatory, antioxidant and anticancer properties
• Flavonoids and polyphenols: Phytonutrients with antioxidant properties that protect your heart and brain

Side effects of eating kale

For most people, kale is safe to eat. But Palma notes a few precautions to take:

• Pesticides: Like many leafy greens, kale is often grown with pesticides, so rinse it well under cold running water. (No soap necessary.)
• Potassium: Anyone who needs to watch their potassium intake — like those with chronic kidney disease or on dialysis — should avoid eating too much kale (or any other potassium-rich food).
• Vitamin K: People on blood thinners may not want to have a drastic change in their kale consumption. Vitamin K helps blood to clot, and a significant change in how much a person eats can affect how well their blood thinner works.

Ways to eat kale

You can eat kale raw, wilted or sautéed. Try adding it to any salad or savory dish that contains other vegetables. Here are some recipe ideas to help get you started:

• Salads: For a different twist on a classic salad, try a California kale Cobb salad.
• Snacks: Make healthy, crispy baked kale chips in the oven for a snack.
• Soups: Mix kale into spicy lentil soup.
• Smoothies: If you don’t enjoy the flavor or texture of kale, get the health benefits by blending it with other fruits and vegetables, like in this green grape smoothie.