Kale is a nutritious food rich in antioxidants, vitamin C, vitamin K, and beta-carotene. It also contains nutrients that can support eye health, weight management, heart health, and more.

Loaded with important micronutrients and antioxidants, kale is one of the most nutritious leafy greens available.

In fact, kale contains a variety of beneficial compounds, some of which have powerful medicinal properties.

Plus, it’s versatile and boasts a nutty, earthy flavor that works well in a wide range of recipes.

Here are 9 health benefits of kale that are supported by science.

Share on PinterestMphillips007/iStock

1. Highly nutritious

Kale is a popular vegetable and a member of the cabbage family.

It is a cruciferous vegetable and is closely related to cabbage, broccoli, cauliflower, collard greens, and Brussels sprouts.

There are many different types of kale. The leaves can be green or purple, and have either a smooth or curly shape.

The most common type of kale is called curly kale or Scots kale, which has green and curly leaves with a hard, fibrous stem.

A single cup, or 21 grams (g), of raw kale contains (1):

• Calories: 7
• Carbs: 1 g
• Fiber: 1 g
• Vitamin K: 68% of the Daily Value (DV)
• Vitamin C: 22% of the DV
• Manganese: 8% of the DV
• Vitamin A: 6% of the DV
• Riboflavin: 5% of the DV
• Calcium: 4% of the DV

Each serving also contains a small amount of folate, vitamin B6, potassium, magnesium, and iron.

Adding more kale to your diet is a great way to boost your intake of these key vitamins and minerals, along with other important nutrients.

Summary

Kale is low in calories and contains several important nutrients, including vitamin K, vitamin C, and manganese.

2. Provides powerful antioxidants

Like other leafy greens, kale is very high in antioxidants.

These include beta-carotene and vitamin C, as well as various flavonoids and polyphenols (2).

Antioxidants are substances that help counteract oxidative damage by neutralizing free radicals in the body (3).

Oxidative damage is believed to be among the leading drivers of aging and many chronic conditions, including cancer (4).

But many substances that happen to be antioxidants also have other important functions.

This includes the flavonoids quercetin and kaempferol, which are found in relatively large amounts in kale (5).

Interestingly, test-tube and animal studies suggest that these compounds may help ease inflammation, support heart health, slow the growth of cancer cells, and protect against chronic disease (6, 7, 8).

Summary

Many powerful antioxidants are found in kale, including quercetin and kaempferol, which have numerous beneficial effects on health.

3. Excellent source of vitamin C

Vitamin C is an important water-soluble antioxidant that serves many vital functions in the body’s cells.

For example, it is necessary for the synthesis of collagen, the most abundant structural protein in the body (9).

Kale is higher in vitamin C than most other greens, containing about three times much as spinach and collard greens (1, 10, 11).

This makes kale an excellent addition to a healthy, well-rounded diet, alongside other fruits and vegetables rich in vitamin C.

Summary

Kale is a good source of vitamin C, an antioxidant that aids in the synthesis of collagen and has many important roles in the body.

4. May lower cholesterol levels

Cholesterol has many important functions in the body.

For instance, it is used to make bile acids, which are substances that help the body digest fats (12).

The liver turns cholesterol into bile acids, which are then released into the digestive system whenever you eat a high fat meal (13).

When all the fat has been absorbed and the bile acids have served their purpose, they are reabsorbed into the bloodstream and used again.

Certain substances in kale can bind bile acids in the digestive system and prevent them from being reabsorbed. This reduces the total amount of cholesterol in the body (14).

One study in 149 people with metabolic syndrome found that consuming 14 g of kale powder every day for 8 weeks significantly reduced levels of LDL (bad) cholesterol, along with blood pressure, belly fat, and fasting blood sugar levels (15).

According to one older study, steaming kale dramatically increases the bile acid binding effect. Steamed kale is actually 13% as potent as cholestyramine, a cholesterol-lowering drug that functions in a similar way (16).

Summary

Kale contains substances that bind bile acids and lower cholesterol levels in the body. Steamed kale is particularly effective.

5. Excellent source of vitamin K

Vitamin K is an important nutrient.

It is absolutely critical for blood clotting, and does this by “activating” certain proteins and giving them the ability to bind calcium (17).

The well-known anticoagulant drug Warfarin actually works by blocking the function of this vitamin (18).

Kale is an excellent source of vitamin K, with a single raw cup containing almost 70% of the recommended daily amount (1).

The form of vitamin K in kale is K1, which is different than vitamin K2. Vitamin K2 is found in fermented soy foods and certain animal products and may help prevent heart disease and osteoporosis (19).

Summary

Vitamin K is an important nutrient that is involved in blood clotting. A single cup of kale contains nearly 70% of the DV for vitamin K.

6. Contains anti-cancer compounds

Cancer is a condition characterized by the uncontrolled growth of cells (20).

Kale is actually loaded with compounds that are believed to have protective effects against cancer.

One of these is sulforaphane, a substance that has been shown to help block the formation of cancer at the molecular level (21, 22).

It also contains a indole-3-carbinol, another substance that is believed to help prevent cancer (23).

Studies have shown that cruciferous vegetables (including kale) may significantly lower the risk of several cancers, although the evidence in humans is mixed (24, 25, 26).

Summary

Kale contains substances that have been shown to help fight cancer in test-tube and animal studies, but human evidence is mixed.

7. High in beta-carotene

Kale is often claimed to be high in vitamin A, but this is not entirely accurate.

It is actually high in beta-carotene, an antioxidant that the body can convert into vitamin A (1, 27).

Adding kale to your diet, alongside a variety of other foods rich in vitamin A, can help you meet your needs for this essential vitamin.

Summary

Kale is very high in beta-carotene, an antioxidant that is converted to vitamin A.

8. Could support eye health

Though your vision tends to worsen as you get older, there are certain nutrients that may help support healthy vision over time.

Two of the main ones are lutein and zeaxanthin, carotenoid antioxidants that are found in large amounts in kale and some other foods (1, 27).

Many studies have shown that people who eat enough lutein and zeaxanthin have a lower risk of macular degeneration and cataracts, two common eye disorders (28, 29).

Summary

Kale is high in lutein and zeaxanthin, two nutrients that have been linked to a reduced risk of macular degeneration and cataracts.

9. May promote weight loss

Kale has several properties that can support weight management.

For starters, it is very low in calories but still provides significant bulk that should help you feel full (1).

Because of the low calorie and high water content, kale has a low energy density. Eating plenty of foods with a low energy density has been shown to aid weight loss in numerous studies (30, 31).

Kale also contains a small amount of fiber, which is an important nutrient that has been linked to weight loss (32).

Although there are no studies directly testing the effects of kale on weight loss, it makes sense that it could be a useful addition to a weight loss diet.

Summary

As a nutrient-dense, low calorie food, kale makes an excellent addition to a weight loss diet.

The bottom line

Fortunately, adding kale to your diet is relatively simple. You can simply add it to your salads or use it in recipes.

A popular snack is kale chips, where you drizzle some extra virgin olive oil or avocado oil on your kale, sprinkle it with salt, and then bake in it an oven until dry.

It tastes absolutely delicious and makes a great crunchy, super healthy snack.

A lot of people also add kale to their smoothies in order to boost the nutritional value.

At the end of the day, kale can definitely be a healthy and nutritious addition to a balanced diet and can be enjoyed in a variety of recipes.