Collard greens (collards) are various loose-leafed cultivars of Brassica oleracea, part of the Acephala group, which also contains cabbage and broccoli.
The plants are grown for their large, dark-colored, edible leaves and as a garden ornamental, mainly in Brazil, Portugal, the southern United States, many parts of Africa, Montenegro, Bosnia and Herzegovina, southern Croatia, northern Spain and in northern India. They are classified in the same cultivar group as kale and spring greens, to which they are genetically similar. The name "collard" is a corrupted form of the word "colewort" (the wild cabbage plant).
The plant is also called "couve" in Brazil and in Portugal, "couve galega" or "couve portuguesa" (among several other names) in Cape Verde, "berza" in Spanish-speaking countries, "col" in Colombia, "raštika" in Bosnia and Herzegovina and Croatia and "raštan" in Montenegro and Serbia. In Kashmir, India, it is called "haakh". In Tanzania and Kenya it is more commonly known by its Swahili name, "sukuma wiki", and is often confused with kale. In New Zealand, it is called "dalmatian cabbage".
Widely considered to be a healthy food, collards are good sources of vitamin C and soluble fiber, and contain multiple nutrients with potent anticancer properties, such as diindolylmethane and sulforaphane. Roughly a quarter pound (approx. 100 g) of cooked collards contains 46 calories.
Collard greens are also a high source of vitamin K and are recommended to be eaten in moderation by individuals taking blood thinners.
Researchers at the University of California at Berkeley have recently discovered that 3,3'-diindolylmethane in Brassica vegetables such as collard greens is a modulator of the innate immune response system with potent antiviral, antibacterial and anticancer activity.
In India Kashmir Valley collard greens are included in almost every meal, with both leaves and roots consumed. Leaves in the bud are harvested by pinching in early spring when the dormant buds sprout and give out tender leaves. Also, seedlings of 35–40 days' age, as well as mature plants, are pulled out along with roots from thickly sown beds. When the extending stem bears alternate leaves in quick succession during on-season, older leaves are harvested periodically. Before the autumn season, the apical portion of stem is removed along with the whorled leaves. It is called haak there.
The roots and the leaves may be cooked together or separately. A common dish is haak rus, a soup of whole collard leaves cooked in water, salt and oil along with many other spices,usually consumed with rice. The leaves are also cooked along with meat, fish or cheese. In the winter, collard leaves and roots are fermented to form a very popular pickle called haak-e-aanchaar.
Health benefits of Collard greens
Wonderfully nutritious collard leaves are very low in calories (provide only 30 calories per 100 g) and contain no cholesterol. However, its green leaves contain a very good amount of soluble and insoluble dietary fiber that helps control LDL cholesterol levels and offer protection against hemorrhoids, constipation as well as colon cancer diseases.
Widely considered to be wholesome 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.
The leaves are also an excellent source of folates, provides about 166 µg or 41.5% of RDA. Folates are important in DNA synthesis and when given during the 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 an excellent source of vitamin-A (222% of RDA per 100 g) and carotenoid 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 healthy vision. Consumption of natural fruits rich in flavonoids helps to protect from lung and oral cavity cancers.
This leafy vegetable contains amazingly high levels of vitamin-K, provides staggering 426% of recommended daily levels per 100 leaves. Vitamin K has a potential role in the increase of bone mass by promoting osteotrophic activity in the bone. It also has the 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.