Collard greens are loose leaf greens. Like kale, they belong to the cruciferous family.

Unlike kale’s curly, narrow leaves, collard greens’ leaves are large, smooth, and flat.

This versatile vegetable is rich in many vitamins, minerals, and antioxidants, and eating it regularly might reduce your risk of developing certain diseases.

This article reviews all you need to know about collard greens, including their nutrition, benefits, downsides, and how to serve them.

raw collard greensShare on Pinterest
Joseph De Leo/Offset Images

Despite their low calorie count, collard greens contain many important nutrients.

Just 2 cups (72 grams) of raw collard greens provide (1):

  • Calories: 24
  • Carbs: 4 grams
  • Fiber: 2.8 grams
  • Protein: 2 grams
  • Fat: 0.4 grams
  • Vitamin K: 128% of the Daily Value (DV)
  • Calcium: 16% of the DV
  • Vitamin C: 28% of the DV
  • Folate: 23% of the DV
  • Vitamin A: 20% of the DV
  • Magnesium: 5% of the DV
  • Potassium: 3% of the DV
  • Phosphorus: 1% of the DV

Additionally, they’re rich in beneficial plant compounds known as antioxidants — particularly the types called phenols, polyphenols, and alpha-lipoic acid. Antioxidants reduce oxidative stress by combating free radicals in your body (2).

summary

Collard greens are nutrient dense and low in calories. They’re an excellent source of calcium, folate, and vitamins K, C, and A. Furthermore, they’re high in fiber and antioxidants.

Studies on the health benefits of collard greens alone are limited.

Still, several studies have analyzed the health benefits of cruciferous vegetables like collard greens as a group.

May protect against cancer

Cruciferous vegetables, including collard greens, may have anticancer effects.

In fact, both older and newer research shows that people with a high intake of cruciferous vegetables have a reduced risk of developing certain types of cancers, including prostate, breast, ovarian, lung, bladder, and colon cancer (3, 4).

The link between eating cruciferous vegetables and reduced cancer risk has also been demonstrated by older and newer test-tube and animal studies (5, 6, 7, 8, 9).

This promising benefit might be attributable to plant compounds called glucosinolates, which are found in cruciferous vegetables.

When broken down in your body, glucosinolates are converted to isothiocyanate (ITC). ITC protects your cells from damage and may help prevent various forms of cancer (10, 11, 12).

Still, human studies and studies on collard greens alone are limited. Further research is warranted to better understand how this vegetable may help prevent cancer.

Improves bone health

Collard greens are especially rich in calcium and vitamin K, both of which are important for bone health.

In fact, just 1 cup (170 grams) of these cooked greens provides 27% of the DV for calcium and an impressive 883% of the DV for vitamin K (13).

Almost all your body’s calcium is stored in your bones and teeth, where it supports their structure and function (14).

If you don’t get enough calcium for long periods, your bones may start to break down, making them thinner and more vulnerable to fractures. This happens because your body needs the stored calcium for other important functions like nerve signaling and muscle movement (15).

Getting enough calcium is particularly important for older adults, especially postmenopausal women. It can help reduce gradual bone loss, which is a normal part of aging (14).

Meanwhile, vitamin K activates proteins that promote bone health and bone metabolism (16).

For example, many older and newer observational studies speculate that a low intake of vitamin K may be linked to an increased risk of bone fractures. Yet, controlled studies have been inconclusive, so more research is needed (17, 18, 19).

May boost eye health

Collard greens are chock-full of nutrients that are good for your whole body, including your eyes.

These green leafy vegetables are not only rich in vitamin A, which has been shown to play a crucial role in vision, but also antioxidants like lutein and zeaxanthin (20, 21, 22).

Lutein and zeaxanthin are both a part of the colorful carotenoid family and can be found in the macula and retina of your eyes (23, 24).

Studies have shown that these antioxidants may help prevent eye conditions like age-related macular degeneration, cataracts, and diabetic retinopathy (25, 26).

Plus, one study showed that eating one or more servings of collard greens per week was linked to a 57% decreased risk of developing glaucoma (27).

May benefit heart health

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death in the United States (28).

Fortunately, many studies have demonstrated that lifestyle changes like increasing physical activity, avoiding tobacco use, and eating more cruciferous vegetables can reduce your risk of heart disease (29).

It’s also worth noting that cruciferous and leafy green vegetables may benefit heart health more than other vegetable families (29).

Lastly, one animal study observed that collard greens improved heart health measures like total and LDL (bad) cholesterol, as well as systolic blood pressure (the top number of a reading) (30).

Supports digestive health

Adding more collard greens to your diet is likely to boost your fiber intake. Fiber can improve your digestive health by promoting regularity and feeding your healthy gut bacteria (1, 31).

Plus, collard greens and other cruciferous vegetables contain a plant compound called dietary sulforaphane (32).

It’s speculated that sulforaphane may prevent the overgrowth of Helicobacter pylori, a bacterium that can attack the lining of your stomach and cause symptoms like bloating, nausea, and stomach pain (33, 34).

Eating a diet rich in sulforaphane has also been shown to improve symptoms of constipation in adults (35).

summary

Collard greens may protect against cancer and improve bone, eye, digestive, and heart health.

Collard greens are generally safe to enjoy, though a few precautions are warranted.

First, this vegetable is exceptionally high in vitamin K, a nutrient involved in the process of coagulation, or blood clotting.

According to older research, a large intake of collard greens could interfere with blood-thinning drugs like warfarin (36).

However, one small but more recent study suggested that increasing vitamin K may stabilize anticoagulation therapy (37).

If you’re taking a blood thinner, it’s recommended that you consume consistent amounts of vitamin K each day. An irregular intake of vitamin-K-rich foods may make it difficult for your doctor to prescribe the correct medication dosage (38).

Collard greens are also a good source of fiber. Even though including fiber-rich foods in your diet is good for your health, adding too much of it too quickly may cause intestinal gas or bloating.

Thus, if you’re interested in adding collard greens to your diet, aim to do so gradually, especially if you’re not used to eating many high fiber foods.

Furthermore, older studies recommend that as you increase your fiber intake, you should prioritize drinking plenty of water and chewing your food thoroughly (39).

summary

Collard greens are high in vitamin K, so if you’re taking a blood-thinning medication like warfarin, you should proceed with caution. Collard greens are also rich in dietary fiber, so eating them may promote flatulence and bloating.

Although commonly served cooked, collard greens can also be enjoyed raw.

They have a mild flavor that’s less bitter than that of kale. Like kale, they contain a tough stem and center rib that many people prefer to remove before eating.

They’re easy to enjoy fresh in salads, slaws, smoothies, sandwiches, or wraps. Additionally, chop or shred them and add them to soups, stews, omelets, and casseroles to increase the nutrient density of your recipes. They can also be sautéed and enjoyed as a side dish.

Here are some other tasty ways to add collard greens to your diet:

  • sauté them with oil or butter along with herbs, spices, or minced garlic
  • chop them and add them to a scrambled egg mixture
  • pulse them with toasted nuts, Parmesan cheese, olive oil, garlic, and salt to make pesto
  • toss a few leaves with olive oil, a squeeze of lemon, and a pinch of salt
  • slice them to use as a pizza topping with fresh mozzarella and tomatoes
  • add a few chopped leaves to homemade chili or stew
  • chop and mix them into a pot of brown rice with red pepper flakes and paprika
  • blend them with herbs like parsley and cilantro, olive oil, garlic, and lemon juice to make salad dressing
  • roast leaves with olive oil and salt for an alternative to fried potato chips
  • boil and simmer them in well-seasoned broth with meat for added flavor (this creates a potlikker)
summary

Leafy collard greens are easy to prepare. Enjoy them as a side dish on their own or incorporate them fresh or cooked into countless dishes like salads, casseroles, omelets, pesto, chili, or stews.

Collard greens are a type of cruciferous vegetable.

They contain impressive amounts of vitamins K and A, calcium, folate, and antioxidants, all of which your body needs to stay healthy.

With their mild flavor, they’re a versatile vegetable. Enjoy them sautéed as a side dish or add them to salads, smoothies, stews, casseroles, and more.

Eating collard greens may lower your risk of certain types of cancer and promote bone, eye, heart, and digestive health.

Try incorporating this versatile vegetable to boost the nutrient content of your dishes and add variety to your diet.