Health Benefits of Kale

Medically Reviewed by Dany Paul Baby, MD on November 27, 2022
3 min read

Kale is a leafy green vegetable that has been grown in Europe since the Middle Ages. In the last five years, its popularity has soared in the U.S. along with its reputation as a superfood loaded with nutrients and antioxidants.

Kale is in the cruciferous family with broccoli, Brussels sprouts, and other vitamin-packed green vegetables. Kale is widely available, from grocery stores to farmer’s markets, and it’s commonly sold fresh in bunches or frozen, already rinsed and trimmed.

Common types of kale include the most popular curly kale, with wide ruffled leaves, or dinosaur kale, with narrower, wrinkly leaves. The less commonly available types redbor and Russian kale can have red or purple leaves.

Many healthy foods must be consumed in moderation because they contain large amounts of fat or calories. Kale, however, boasts a wealth of nutrition and is fat-free, sugar-free, cholesterol-free, and exceptionally low in sodium and calories. This balance makes it a great option for adding to your diet, particularly if you’re looking for low-calorie options or weight-friendly options. Because kale contains so many vitamins and nutrients, it can contribute to supporting many health benefits, including:

Good Eyesight

A 1-cup serving of fresh kale contains over 20% of the recommended daily intake of vitamin A, which supports eye health and is vital for vision. 

One 100g serving of kale also provides over 100% of the daily value for vitamin C, which has been associated with a lower risk of cataracts. Kale is also rich in lutein and zeaxanthin, antioxidants that reduce your risk of macular degeneration and other age-related eye diseases.

Healthy Heart

Kale offers an abundance of nutrients that support heart health, including potassium, fiber, folate, and calcium. As part of a heart-healthy diet, kale can reduce the risk of heart disease by helping lower LDL cholesterol, or “bad cholesterol”.

Lower Blood Pressure

Some foods can help lower blood pressure naturally, and kale is one of them. Because it contains high levels of magnesium, calcium, and potassium, along with other vitamins and fiber all working together, kale can help lower blood pressure.

Strong Bones

Kale is a good nondairy source of calcium, which is needed to maintain the health and function of your heart and other muscles, as well as your bones and teeth. If you do not get enough calcium, the body must use calcium from your bones to support your vital organs, leading to bone loss. Adequate calcium intake throughout life can help reduce the risk of osteoporosis, a common disorder in which the bones grow fragile and become prone to fractures.

Vitamin K is also critical for bone health. Just one cup (21 g) of fresh kale gives you a whopping 80.3 micrograms of vitamin K, which is over 67% of the average recommended daily values of 120 micrograms for adult men over age 19 and 90 micrograms for adult women over age 19.

In addition to the nutrients mentioned above, kale is a good source of vitamin B6, copper, and manganese.

Nutrients per Serving

One cup of fresh, chopped kale contains:

  • Calories: 34
  • Protein: 0.6 grams
  • Fat: 0 grams
  • Carbohydrates: 0.9 grams
  • Fiber: 1 gram
  • Sugar: 0 grams

Things to Watch Out For
The vitamin K in kale is a benefit to most people but can interfere with the effects of blood thinners. If you take blood thinners, check with your doctor before adding kale to your diet. Eating about the same amount of leafy green vegetables every day may allow your doctor to adjust your medication so that you can safely enjoy their other health benefits.

Select dark green bunches of kale with small or medium leaves and no wilting. It will stay fresh and tender for about five days in the refrigerator. Wash kale thoroughly before using. If sautéing or roasting, be sure to dry the leaves thoroughly for best results. Although the middle rib is edible, most people find it bitter and remove it before cooking. 

Kale can be sautéed, roasted, baked, or steamed. Or, enjoy it raw in a salad. Here are a few ideas for adding more kale to your diet:

  • Homemade oven-baked kale chips make for a crunchy, healthy snack.
  • Kale salads stay crisp longer than lettuce or spinach salads, making them a great choice for picnics or potlucks.
  • Toss in a handful of kale leaves when making homemade pesto, hummus, or smoothies.
  • Tear raw kale leaves into small pieces and add to stir-fry dishes, soups, or casseroles.