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Collard Greens: Fight Cancer, Provide Detox Support and More


Collard greens - Dr. Axe

Collard greens (or collards) are various loose-leafed plants that belong to the Brassica oleracea species. This beneficial vegetable is related to cabbage, Swiss chard, broccoli, cauliflower, kale and Brussels sprouts, as they all belong to the Acephala group.

The collard green plant is grown for its large, dark-colored and edible leaves; it grows in Brazil, Portugal, the southern United States, many parts of Africa, Montenegro, Bosnia and Herzegovina, southern Croatia, northern Spain and northern India. Similar to kale, it has an upright stalk, often growing up to two feet tall.

The leaves are thick and have a slightly bitter taste. Cruciferous vegetables, like collard greens, are unique because they’re rich in sulfur-containing compounds called glucosinolates, which support detoxification, and indole-3-carbinol that greatly reduces the risk of breast, colon and lung cancer.

Collard greens are a great vitamin K and vitamin A food; they’re also rich is soluble fiber and have strong antioxidant properties. By adding collard greens to your diet, you reduce disease-causing inflammation, cure digestive conditions, detox your body and boost cardiovascular health.

One of the most important components of collard greens, and other cruciferous vegetables, is glutathione. This peptide consists of three key amino acids that play several vital roles in the body. It helps the liver cleanse and detoxify fat, boosts immune function, fights cancer, protects the body from environmental toxins, and prevents drug resistance.
Glutathione is so important to our health that longevity researchers believe the levels that are present in our cells serve as a predictor of how long we are going to live. Collard greens boost glutathione levels and allow this molecule to do its magic.

Nutrition Facts

Collard greens are among the best vitamin C foods, and they’re a good source of vitamin K and soluble fiber. They also contain multiple nutrients with potent anti-cancer properties, such as diindolylmethane and sulforaphane.

One cup of cooked collard greens has about:

  • 49 calories
  • 1 gram of fat
  • 30 milligrams sodium
  • 9 grams carbohydrate
  • 5 grams dietary fiber
  • 1 gram sugar
  • 4 grams protein
  • 836 micrograms vitamin K (1,045 percent DV)
  • 15,416 international units vitamin A (308 percent DV)
  • 35 milligrams vitamin C (58 percent DV)
  • 1.7 milligrams vitamin E (8 percent DV)
  • 0.2 milligrams vitamin B6 (12 percent DV)
  • 0.4 milligrams pantothenic acid (4 percent DV)
  • 177 micrograms folate (44 percent DV)
  • 0.2 milligrams riboflavin (12 percent DV)
  • 0.1 milligrams thiamine (5 percent DV)
  • 1.1 milligrams niacin (5 percent DV)
Collard greens - Dr. Axe


1. Help Prevent Cancer

Collard greens detoxify the body, have high levels of antioxidants and reduce inflammation — making this powerful vegetable a natural cancer fighter and preventer.

According to the National Cancer Institute, the secret behind the cancer-killing ability of collard greens and other cruciferous veggies is they’re rich in glucosinolates — a large group of sulfur-containing compounds.

These chemicals are known to break down during the chewing and digestion process into biologically active compounds that prevent the growth of cancer cells; the compounds are called indoles, thiocyanates and isothiocyanates, and studies suggest that they protect rats and mice against cancer of the bladder, breast, colon, liver, lung and stomach.

These powerful glucosinolates are also known to reduce inflammation, reprogram cancer cells to die off, prevent tumor formation and metastasis, deactivate carcinogens, and contain antibacterial and antiviral properties.

2. Provide Detox Support

Just like the health benefits of kale, their cruciferous cousin, one of the top health benefits of collard greens is that they’re a natural detoxifier. They not only help remove toxins, but they eliminate them from the body, too. A component in collard greens called isothiocyanates (ITCs) is made from glucosinolates. They’re reported to help detox the body at the cellular level.

Glucosinolates help activate detoxification enzymes and regulate their activity; they also trigger the liver to produce detoxifying enzymes that block free-radical attacks on your DNA. By eating collard greens regularly, you help the body eliminate toxins, or poisons, in the body that come from processed foods, pollutants, pesticides and pharmaceuticals.

3. Support Cardiovascular Health

Because collard greens reduce inflammation, they impact our cardiovascular health. Vitamin K, which is abundant in collard greens, is a critical nutrient for reducing inflammation and protecting cells that line blood vessels, including both veins and arteries.

Vitamin K has been shown to help prevent calcification of arteries, one of the leading causes of heart attacks. It works by carrying calcium out of the arteries and not allowing it to form into hard, dangerous plaque deposits. It’s a natural remedy for high blood pressure and reduces the risk of health conditions such as stroke, heart attack and diabetes.

4. Lower Cholesterol

Cholesterol is a naturally occurring substance made by the liver and required by the body for the proper function of cells, nerves and hormones. It travels in the fatty acids of the bloodstream and can build up in the walls of the arteries, decreasing the flow of blood to vital areas of the body.

Collard greens lower cholesterol naturally because the leaves are high in fiber. Soluble fiber binds cholesterol in the digestive system, causing it to be excreted by the body.

A study published in the American Journal of Preventive Medicine concluded that a fiber supplement provided significant and sustained reductions in LDL (bad cholesterol) without reducing HDL (good cholesterol) or increasing triglycerides over a 51-week treatment period.

5. Support Digestive System

Because collard greens are some of the best high-fiber foods, eating this beneficial vegetable stimulates the digestive system. Collard greens consumption can be added as an irritable bowel syndrome (IBS) diet food, for example, because they combat IBS. The amount of people who now struggle with some form of IBS is a shocking 60 million people — that’s 20 percent of Americans!

IBS generally causes severe symptoms, such as diarrhea or ulceration of the digestive tract. One major cause of IBS is a low-fiber diet and nutritional deficiencies. Because of the high fiber content in collard greens, they treat this syndrome that’s often related to a number of other health conditions, including ulcerative colitis, Crohn’s disease and leaky gut syndrome.

The glucoraphanin present in collard greens also helps protect the health of our stomach lining by preventing bacterial overgrowth and the clinging of bacterium to our stomach wall.

6. High Source of Bone-Building Vitamin K

A cup of cooked collard greens has way over 100 percent of the recommended daily value of vitamin K, an essential fat-soluble vitamin. Vitamin K is most well-known for being responsible for bone building and blood clotting; in fact, vitamin K builds bones better than calcium!

Human intervention studies demonstrate that vitamin K not only increases bone mineral density in osteoporotic people, but reduces fracture rates, too.

Vitamin K is also one of the most crucial vitamins for preventing heart disease. Studies show that individuals who increase their intake of dietary vitamin K have a lower risk of cardiovascular mortality. A vitamin K deficiency can lead to health conditions, including IBS, heart disease, weakened bones, tooth decay and cancer.

7. High Source of Inflammation-Reducing Vitamin A

Vitamin A is a fat-soluble vitamin that’s also a powerful antioxidant. With a cup of collard greens fulfilling 300 percent of your recommended daily value, you surely experience the amazing vitamin A benefits with this nutritious vegetable.

Vitamin A plays a critical role in maintaining healthy vision, neurological function and healthy skin. It’s essential for skin health, and a deficiency can lead to a poor complexion.

Studies prove that consuming vitamin A-rich foods can fight acne and improve overall skin health. Like all high-antioxidant foods, it reduces inflammation by fighting free radical damage, which is vital for good health and longevity.

8. Help Maintain Healthy Weight

Leafy greens like collard greens, kale, spinach and Swiss chard are chock-full of nutrients and iron. These fat-burning foods help keep muscles functioning properly and burning calories long after a workout.

Because collard greens are packed with vitamin K, eating the leaves keeps our bones strong and helps ward off and naturally treat osteoporosis, keeping the body moving normally well into old age. Collard greens are a nutritionally dense vegetable, and the benefits your body gets for the amount of calories contained in these vegetables means you get more bang for your nutritional buck.

You can chow down on these healthy greens guilt-free; plus, you can begin to crowd out other less nutritious foods that don’t boost your health and well-being.

Interesting Facts

Collard greens date back to prehistoric times and they are one of the oldest members of the cabbage family. The Ancient Greeks cultivated several forms of both collard greens and kale. In America, African slaves and Native Americans shared ideas on how to cook collard greens; in fact, the Southern style of cooking these greens came with the arrival of African slaves to the southern colonies.

Collard greens did not originate in Africa, but the habit of eating greens that have been cooked down into a low gravy, and drinking the juices from the greens, which is known as “pot likker,” is of African origin.

Today, collard greens are a stable in U.S. southern cuisine, and it’s eaten year-round. In some cultures, collards are eaten on New Year’s Day, along with black-eyed peas or field peas and cornbread; it’s served to ensure wealth in the coming year, as the leaves resemble folding money. Collard greens are often prepared with other leafy vegetables like kale, turnip greens, spinach and mustard greens. They are commonly served with smoked or salted meats, diced onions, vinegar, salt and pepper.

How to Find and Use

You can find collard greens at just about any food store. When buying them, look for the freshest option. They should be a vibrant dark-green color, and the leaves should be crisp and full. Try to find the organic option to ensure the full health benefits.

Once you get your greens home, wash them well first — you want to remove any soil or debris that is left on the leaves. Once they are clean, they’re ready for cooking.

Collard greens can be stored in the refrigerator for three to five days. Try wrapping them in a damp paper towel and storing them in an open ziploc bag. You can also freeze the leaves for smoothies — they can last for months when frozen. If you feel that the stalks of the leaves are too tough, go ahead and remove them but remember that they’re edible.

There are a ton of fun and easy ways to use collard greens. You can add them to meals throughout the day — like chopping them and adding to a frittata, or swapping out the starchy-carb wrap and using collard green leaves instead. You can sauté collard greens and put them as a side to a meat dish, or add them to smoothies, soups, dips and sauces.


The easiest way to get a ton of green veggies into your daily diet — a smoothie! Try a green smoothie recipe that includes collard greens and a ton of other nutritious vegetables that boost the immune system and keep your body running smoothly.

Cooking collard greens is similar to preparing Swiss chard greens. They’re both vibrant leafy veggies that have amazing health benefits. Swiss chard nutrition includes its high levels of antioxidants and an impressive amount of potassium, magnesium, calcium, copper, and even more vitamins and minerals.

With high levels of vitamin K, vitamin A, vitamin C and many trace minerals, there’s almost no health condition that Swiss chard can’t help. Try our chard greens recipe; you can add collard greens to the mix or swap out the chard greens completely.

A really great and healthy idea is using collard green leaves as wraps. You can add chicken, turkey, beef, veggies and cheese to collard green leaves and avoid those white carbohydrates that have little nutritional value.

Creamy Broccoli Soup Recipe

This creamy broccoli soup is absolutely delicious and full of healthy fats from coconuts. The collard greens and other cruciferous vegetables in this recipe reduce inflammation, fight free-radical damage to your cells and aid your digestive system.

Side Effects

When you buy collard greens, it’s important that you choose the organic option because conventionally grown greens may be contaminated with concentrations of organophosphate insecticides, which are considered highly toxic to the nervous system.

Collard greens naturally contain substances called oxalates, which are normally not a health concern when eaten in normal, moderate amounts, but in rare cases eating high levels of oxalates can cause certain health problems. Oxalates are most known for potentially interfering with the absorption of certain minerals, such as calcium; however, experts still agree that oxalates do not pose a threat for the vast majority of people and that their presence in vegetables like collard greens does not outweigh the many health benefits of this vegetable.

If you have a history of gallbladder issues, avoid eating a lot of leafy greens, like collard greens, because of the oxalate levels.

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