Collard greens are part of the cruciferous vegetable family. They contain nutrients that can play an important role in a healthful diet.
A diet that is rich in fruits and vegetables appears to help reduce the risk of many lifestyle-related health conditions.
Vitamin K acts as a modifier of bone matrix proteins, it improves calcium absorption, and it may reduce urinary excretion of calcium.
One cup of boiled collard greens provides 770 micrograms of vitamin K.
The 2015-2020 United States Dietary Guidelines recommend that a woman aged 19 to 30 years should consume 90 mcg a day of vitamin K, and a man of the same age should consume 120 mcg.
One cup of collard greens provides this much vitamin K several times over.
Studies suggest that people who eat plenty of cruciferous vegetables have a lower risk of developing various types of cancer, including cancer of the upper digestive tract, colorectal, breast cancer, and kidney cancer.
Cruciferous vegetables have sulfur-containing compounds known as glucosinolates.
These compounds may help prevent the cancer process at different stages of development for lung, colorectal, breast, and prostate cancers, and possibly melanoma, esophageal cancer, and pancreatic cancer.
In 2017, researchers published the results of a study involving nearly 3,000 people. They were looking for possible links between the incidence breast cancer and the consumption of cruciferous vegetables.
The findings suggested that consuming cruciferous vegetables may lower the risk of breast cancer, especially in women who have not yet reached menopause. They note that cooking methods may make a difference, as cooking some cruciferous vegetables can reduce the levels of glucosinolates.
Whether this is true of collard greens or not was unclear from this study, as most people do not eat collard greens raw.
There is evidence that collard greens and other green vegetables that contain high amounts of chlorophyll can help to block the carcinogenic effects of heterocyclic amines. These substances are generated when grilling foods at a high temperature.
Diabetes and liver function
The 2015-2020 Dietary Guidelines for Americans recommend 22.4 to 28 grams of fiber a day for women, depending on age, and 28 to 33.6 grams a day for men.
One cup of boiled collard greens provides nearly 8 grams of fiber.
Collard greens also contain an antioxidant known as alpha-lipoic acid.
Studies suggest that alpha-lipoic acid (ALA) can lower glucose levels, increase insulin sensitivity, and prevent changes related to oxidative stress in people with diabetes. It can also help to regenerate liver tissue.
However, it remains unclear whether ALA can be effective as a long-term treatment. In addition, studies have used intravenous ALA. Oral supplementation may not provide the same benefits.
Excessively high doses of ALA appear to produce adverse effects similar to those caused by too little. While "normal" amounts can help prevent oxidative stress, high levels may lead to cell damage.
Collard greens are high in both fiber and water content. These help to prevent constipation, promote regularity, and maintain a healthy digestive tract.
Healthy skin and hair
Collard greens have a high vitamin A content. Vitamin A is necessary for sebum production, and this keeps hair moisturized.
Vitamin A is crucial for the growth of all bodily tissues, including skin and hair. It also supports the immune system and the eyes and helps keep the body's organs healthy.
An adult woman needs 75 mg of vitamin C a day, and a man needs 90 mg. A cup of boiled collard greens provides nearly 35 mg of vitamin C.
Iron prevents anemia, a common cause of hair loss. A lack of iron in the diet can affect how efficiently the body uses energy. Collard greens, spinach, lentils, tuna, and eggs are good sources of iron.
Adults need to consume 8 mg of iron a day, and women during their reproductive years need 18 mg. One cup of boiled collard greens provides 2.5 mg of iron.
Sleep and mood
Collard greens contain choline, an important neurotransmitter. Choline helps with mood, sleep, muscle movement, learning, and memory functions.
Choline also helps to maintain the structure of cellular membranes, the transmission of nerve impulses, the absorption of fat, and the reduction of chronic inflammation.
Consuming folate may help reduce the risk of depressive symptoms in some people.
Why not grow your own collard greens? You can purchase the seeds online.
One cup of boiled collard greens, drained and without added salt, contains:
- 63 calories
- 5.15 g (g) of protein
- 1.37 g of fat
- 10.73 g of carbohydrate, including 7.6 g of fiber and less than 1 g of sugar
- 268 milligrams (mg) of calcium
- 2.15 mg of iron
- 40 mg of magnesium
- 61 mg of phosphorus
- 222 mg of potassium
- 28 mg of sodium
- 0.44 mg of zinc
- 34.6 mg of vitamin C
- 30 mcg of folate
- 722 micrograms (mcg) of vitamin A (RAE)
- 1.67 mg of vitamin E
- 772.5 mcg of vitamin K
Collard greens are an excellent source of vitamin A, vitamin C, and calcium, a rich source of vitamin K, and a good source of iron, vitamin B-6, and magnesium.
They also contain thiamin, niacin, pantothenic acid, and choline.
Collard greens should have firm, deep green leaves. Smaller leaves will be tenderer and have a milder flavor.
Collard greens keep well in the refrigerator.
Steaming collard greens for 10 minutes or less helps them to retain their nutrients.
Season them with peppers, chopped onions, herbs, and spices.
You can use collard greens:
- raw in salads or on sandwiches or wraps
- braised, boiled, or sautéed
- in soups and casseroles
Another idea is to sauté fresh garlic and onions in extra-virgin olive oil until soft, then add collard greens and continue to sauté until they reach the desired tenderness.
Avoid frying collard greens in bacon fat or lard or overcooking them, as these can create a strong and bitter sulfur taste.
Adding black-eyed peas and brown rice gives a more healthful version of a southern favorite.
You can add a handful of collard greens to a favorite smoothie. This provides extra nutrients without changing the flavor significantly.
Collard green chips
You can make collard-green chips like this:
- Remove the ribs from the collard greens.
- Toss the leaves in extra-virgin olive oil.
- Bake them at 275 degrees Fahrenheit for 15 to 30 minutes until they are crisp.
- Sprinkle lightly with a choice or a combination of cumin, curry powder, chili powder, roasted red pepper flakes, and garlic powder.
People who use blood-thinners, such as Coumadin or warfarin, should not suddenly increase or decrease their intake of foods containing vitamin K, as it plays a major role in blood clotting.
The most important factor in achieving good health and avoiding disease is the overall diet, not a specific food item. Choose collard greens as part of a varied diet with plenty of fresh fruit and vegetables.