7 benefits of kale, from improving digestion to helping fight cancer (2024)

• Kale is packed with minerals like iron, manganese, calcium, copper, and potassium.
• It may also help fight heart disease by lowering cholesterol and aiding weight loss.
• The antioxidants, sulfurous compounds, and fiber in kale may help contribute to cancer prevention.

Kale is a dark, leafy vegetable that is packed with essential vitamins and minerals. In fact, kale is one of the most nutrient-dense foods in the world — one serving has over 450% of your daily value of vitamin K. Eating kale can help boost your health by providing antioxidants, fighting heart disease, and helping to prevent cancer. Here are seven science-backed benefits of adding kale to your diet.

1. Provides antioxidants

"Like other leafy greens, kale is rich in antioxidants," says Samantha Cassetty, MS, RD, nutritionist and co-author of Sugar Shock.

Kale contains several important antioxidants — two cups of raw kale contains:

• Beta-carotene, 1.2 mg, 150% of your recommended daily intake (RDI)
• Vitamin C, 38.4 mg, 46% of your RDI
• Chlorogenic acid, 1,148.8 mg
• Lutein, 79.2 mg

2. May help fight heart disease

"Kale's high fiber content is a beneficial addition to the diet if you're worried about heart disease risk," says Julie Stefanski, RDN, a registered dietitian and spokesperson for the Academy of Nutrition & Dietetics.

This is because eating fiber can help lower cholesterol and change the way your body absorbs sugars, limiting weight gain. Maintaining a healthy weight can help boost your heart's function and lower your blood pressure.

A 2019 review of 185 studies found that eating a diet high in fiber reduced the risk of heart disease by 15% to 30% when compared to consuming a low-fiber diet.

One cup of cooked kale has 5.2 grams of fiber, which makes up 19% of your RDI.

Kale is also high in phytxochemicals, compounds that fight heart disease by reducing inflammation in your body, Stefanski says

3. May promote brain health

Kale provides several nutrients that some studies suggest may support brain health:

• Omega-3 fatty acids can help improve your memory and brain performance, particularly as you grow older, likely because they have an anti-inflammatory effect on your brain. A study from 2010 found that older adults who took omega-3 supplements daily for six months did better on memory and learning tests than those without any treatment.
• Sulforaphane is a compound that fights the effects of inflammation in your body. Reducing inflammation can help boost your cognitive function.
• Iron is also important for your brain health. When your iron levels are low, you may have trouble focusing due to lack of oxygen supply to the brain, from your blood. One cup of cooked kale provides 1.1mg, or 6% of your RDI of iron. Taking in vitamin C along with iron helps you absorb iron more efficiently, so kale's high vitamin C content is an important factor.

4. Provides important minerals

When it comes to nutrients, a little bit of kale can go a long way. So, "if you're not a vegetable lover, adding in kale can give you lots of vitamins and minerals in a moderate amount of leafy greens," Stefanski says.

For example, in one cup of cooked kale, you get a variety of minerals including:

• Manganese: 0.7 mg, 31% of RDI
• Calcium: 195 mg, 15% of RDI
• Copper: 0.1 mg, 10% of RDI
• Magnesium: 32.5 mg, 8% of RDI
• Iron: 1.1 mg, 6% of RDI
• Potassium: 187 mg, 4% of RDI

Getting enough minerals in your diet is important for maintaining the function of your bones, muscles, heart and brain.

Eating kale may be especially helpful for people on a vegetarian or vegan diet. "It can be challenging for people to get enough calcium when they aren't eating dairy foods, so kale can help on that front," Cassetty says.

5. May help fight cancer

Kale contains several important nutrients that may help lower your risk of cancer:

• Antioxidants. "The antioxidants in kale may help guard you against cancer since oxidative stress is thought to promote cancer development," Cassetty says. In particular, beta-carotene and lutein can help limit the growth of cancer cells.
• Sulforaphane. The sulfurous compounds in cruciferous vegetables like kale and broccoli may help protect your body against cancer, says Cassetty. A 2013 meta-analysis of 13 studies found that eating more cruciferous vegetables was associated with a lower risk of breast cancer.
• Fiber. Kale's high fiber content—specifically insoluble fiber—may help lower your risk of colorectal cancer. This is because fiber passes through your colon quickly and may help clear out any cancer-causing compounds.

6. It's a great source of vitamin K

Vitamin K isn't always easy to come by, especially if you don't eat meat. But "kale, collard greens, and Swiss chard are some of the highest sources of the plant version of vitamin K," says Stefanski.

Getting enough vitamin K helps with blood clotting, which aids your body in healing from wounds.

Vitamin K deficiencies have also been linked to a higher risk of bone fractures. A 2009 study found that vitamin K reduced the risk of bone fractures in postmenopausal women. This is particularly important since postmenopausal women are at a higher risk of bone loss.

Your body absorbs vitamin K more easily when you eat it along with a healthy fat or oil, so it may help to eat kale with an oily salad dressing or sautée it in light oil.

One cup of cooked kale offers 544 micrograms of vitamin K, which gives you 453% of your daily value. Eating a large amount of vitamin K in foods isn't harmful to your body — vitamin K is only dangerous when you take too many synthetic supplements.

7. Can improve digestion

Kale contains a type of sugar called sulfoquinovose, which feeds the good bacteria living in your gut. These good bacteria are important for your digestion and help keep down levels of harmful bacteria. This is important because high levels of bad bacteria can lead to diarrhea and malnutrition.

The fiber in kale also adds bulk to your stool, which can help relieve constipation.

Insider's takeaway

Kale is a great source of nutrients like fiber, vitamin K, and omega-3 fatty acids. Eating kale can help ensure adequate mineral intake, offer cancer-fighting antioxidants, and promote brain and heart health.

However, to get these benefits, it's best to combine kale with other healthy foods like whole grains, fruits, vegetables, and nutritious fats. "The overall healthfulness of your diet matters more than any single food," Cassetty says.