Collard greens are highly nutritious staple green “cabbage-like leaves” vegetable. Collards are one of the most popular members of the brassica family, closely related to kale and cabbage and could be described as a non-heading (acephalous) cabbage.
Botanically, the greens are named as Brassica oleracea L. (Acephala group).
 Collards are probably originated in the eastern European or Asia minor region and now a day’s grown almost all parts of the cooler temperate regions The plant grows up to 3-4 feet in height and bears dark green leaves arranged in a rosette fashion around an upright, stocky main stem.

Several cultivar types of collard greens are grown around the planet depending on the soil type, climate etc.

Blue Max:  It has very attractive savoy- like blue-green leaves.

Georgia:  It is also known as Georgia LS or Georgia Southern.  It has blue-green and slightly savoyed leaves.

Vates: Plant is compact and leaves are smooth and dark green.

Champion: Low growing plant, featuring smooth, dark-green leaves with short internodes.

Flash: It is a very uniform Vates type with smooth, dark-green leaves.

Heavy-Crop:  It has very large, slightly savoy like, blue-green leaves. Leaves have close internodes spacing so bunching can be more difficult.

Health benefits

Wonderfully nutritious collard leaves are very low in calories (provide only 30 Cal per 100 g) and contain no cholesterol. However, these green leaves contain very good amount of soluble and insoluble dietary fibre that helps control LDL cholesterol levels and also; offers protection against haemorrhoids, constipation as well as colon cancer diseases.

Widely considered to be healthful foods, collards are rich in invaluable sources of phyto-nutrients with potent anti-cancer properties, such as di-indolyl-methane (DIM) and sulforaphane that have proven benefits against prostate, breast, cervical, colon, ovarian cancers by virtue of their cancer cell growth inhibition and cytotoxic effects on cancer cells.

Di-indolyl-methane has also found to be effective immune modulator, anti-bacterial and anti-viral properties by potentiating Interferon-gamma receptors and production.

The leaves are also an excellent source of folates, provides about 166 mcg or 41.5% of RDA. Folates are important in DNA synthesis and when given during peri-conception period can prevent neural tube defects in the baby.

Fresh collard leaves are also rich in vitamin-C. Provides about 59% of RDA per 100 g.  Vitamin-C is a powerful natural anti-oxidant that offers protection against free radical injury and flu-like viral infections.

Collard greens are also an excellent source of vitamin-A (222% of RDA per 100 g) and flavonoid poly-phenolic anti-oxidants such as lutein, carotenes, zea-xanthin, crypto-xanthin etc. These compounds are scientifically found to have antioxidant properties. Vitamin A also required maintaining healthy mucus membranes and skin and is also essential for vision.  Consumption of natural fruits rich in flavonoids helps to protect from lung and oral cavity cancers.

This leafy vegetable contain amazingly high levels of vitamin-K, provides staggering 426% of recommended daily levels per 100 leaves. Vitamin K has potential role in the increase of bone mass by promoting osteotrophic activity in the bone. It also has beneficial effect in Alzheimer's disease patients by limiting neuronal damage in their brain.

Collards are rich in many vital B-complex groups of minerals such as niacin (vitamin B-3), pantothenic acid (vitamin B-5), pyridoxine (vitamin B-6) and riboflavin.

The leaves and stems are good in minerals like iron, calcium, copper, manganese, selenium and zinc.

Detox Support : The detox support provided by collard greens includes antioxidant nutrients to boost Phase 1 detoxification activities and sulfur-containing nutrients to boost Phase 2 activities. Collard greens also contain phytonutrients called glucosinolates that can help activate detoxification enzymes and regulate their activity. Four key glucosinolates that have been clearly identified in collard greens in significant amounts are glucobrassicin, glucoraphanin, gluconasturtiian, and glucotropaeolin.

If we fail to give our body's detox system adequate nutritional support, yet continue to expose ourselves to unwanted toxins through our lifestyle and our dietary choices, we can place our bodies at increased risk of toxin-related damage that can eventually increase our cells' risk of becoming cancerous. That's one of the reasons it's so important to bring collard greens and other cruciferous vegetables into our diet on a regular basis.

The Antioxidant Benefits: As an excellent source of vitamin C, vitamin A (in the form of carotenoids), and manganese, and a good source of vitamin E, collard greens provide us with 4 core conventional antioxidants. But the antioxidant support provided by collard greens extends far beyond the conventional nutrients into the realm of phytonutrients. Caffeic acid, ferulic acid, quercetin, and kaempferol are among the key antioxidant phytonutrients provided by collard greens. This broad spectrum antioxidant support helps lower the risk of oxidative stress in our cells. Chronic oxidative stress—meaning chronic presence over overly reactive oxygen-containing molecules and cumulative damage to our cells by these molecules—is a risk factor for development of most cancer types. By providing us with such a great array of antioxidant nutrients, collard greens help lower our cancer risk by helping us avoid chronic and unwanted oxidative stress.

Anti-inflammatory Benefits: As an excellent source of vitamin K and a good source of omega-3 fatty acids (in the form of alpha-linolenic acid, or ALA), collard greens provide us with two hallmark anti-inflammatory nutrients. Vitamin K acts as a direct regulator of our inflammatory response, and ALA is the building block for several of the body's most widely-used families of anti-inflammatory messaging molecules. In addition to these two anti-inflammatory components, one of the glucosinolates found in collard greens—glucobrassicin—can be readily converted into an isothiocyanate molecule called I3C, or indole-3-carbinol (I3C). I3C is an anti-inflammatory compound that can actually operate at the genetic level, and by doing so, prevent the initiation of inflammatory responses at a very early stage.

Like chronic oxidative stress and chronic weakened detox ability, chronic unwanted inflammation can significantly increase our risk of cancers and other chronic diseases (especially cardiovascular diseases).

Cardiovascular Support:  Researchers have looked at a variety of cardiovascular problems—including heart attack, ischemic heart disease, and atherosclerosis—and found preliminary evidence of an ability on the part of cruciferous vegetables to lower our risk of these health problems. Yet regardless of the specific cardiovascular problem, it is one particular type of cardiovascular benefit that has most interested researchers, and that benefit is the anti-inflammatory nature of collard greens and their fellow cruciferous vegetables. Scientists have not always viewed cardiovascular problems as having a central inflammatory component, but the role of unwanted inflammation in creating problems for our blood vessels and circulation has become increasingly fundamental to an understanding of cardiovascular diseases. Of particular interest here has been the isothiocyanate (ITC) sulforaphane, which is made from glucoraphanin (a glucosinolate) found in collard greens. Not only does this ITC trigger anti-inflammatory activity in our cardiovascular system, it may also be able to help prevent and even possibly help reverse blood vessel damage.

Digestive Support : The fibre content of collard greens—over 7 grams in every cup—makes this cruciferous vegetable a natural choice for digestive system support. Yet the fibre content of collard greens is only one of their digestive support mechanisms. Researchers have determined that the sulforaphane made from a glucosinolate in collard greens (glucoraphanin) helps protect the health of our stomach lining by preventing bacterial overgrowth of Helicobacter pylori in our stomach or too much clinging by this bacterium to our stomach wall.

Other Health Benefits

The anti-inflammatory nature of glucosinolates/isothiocyanates and other nutrients found in collard greens has been the basis for new research on inflammation-related health problems and the potential role of collard greens in their prevention. Current and potentially promising research is underway to examine the benefits of collard greens in relationship to our risk of the following inflammation-related conditions: Crohn's disease, inflammatory bowel disease, insulin resistance, irritable bowel syndrome, metabolic syndrome, obesity, rheumatoid arthritis, type 2 diabetes, and ulcerative colitis