Collards are large, leafy green vegetables that have smooth dark leaves and a mild flavor. They have become a traditional side dish in Southern cooking and uphold the standards of a true super food. Research shows that collard greens surpass its cruciferous relatives such as broccoli, kale, and Brussel sprouts in terms of its ability to lower cholesterol and decrease cancer risk.
Disease/Ailments:
Cancer prevention
Digestive disorders
Cardiovascular disorders
Chronic inflammatory diseases
Health benefits:
Detoxification: Collard greens contain phytonutrients called glucosinates that can help activate detoxification enzymes and regulate this process. Detoxification occurs in two stages. Antioxidant compounds boost Phase 1 and sulfur-containing nutrients boost Phase 2.
Antioxidant: In addition to the antioxidants commonly known such as vitamin C, beta-carotene, and manganese, collard greens provide phytonutrients that lower chronic oxidative stress. These properties increase the health benefits of collard greens, especially in cancer prevention.
Anti-inflammatory agent: Collard greens are an excellent source of vitamin K and a good source of omega-3 fatty acids. These are two anti-inflammatory agents that regulate the inflammatory response that may cause chronic disease states. One phytonutrient glueobrassicin, is converted into an isotiocyanate compound, which genetically prevents the initiation of the inflammatory response.
Cardiovascular support: The combination of anti-inflammatory properties and cholesterol-lowering activities contributes to cardiovascular support that collard greens provide. Risk of cardiovascular problems such as heart attack, ischemic heart disease, and atherosclerosis, can be lowered by the nutrient content in collard greens. In addition, high folate levels aid in the prevention of homocysteine build-up, which can be harmful to the cardiovascular system.
Digestion regulation: Collard greens are high in fiber and will help regulate the emptying of the colon and aid the digestive support systems. Another digestive benefit comes from sulforaphane made from the glucosinolate phytonutrient found in collard greens that prevents the bacterial overgrowth of Heliobacter pylori in the stomach.
Good source of:
Vitamin K, A, C, folate, manganese, calcium, fiber, iron
Purchasing, storing, & enjoying:
Purchasing: Look for leaves that are firm and vividly deep in color. There should be no sign of discoloration. A bundle of collard greens with smaller leaves will have a milder taste than those with larger leaves. Bundles of collard greens should be stored in the chilled section of the produce area to prevent them from wilting or becoming bitter. Try to purchase organic collard greens. They have been shown by the Environmental Working Group to contain concentrations of organophosphate insecticides, which can be highly toxic to the nervous system. Collard greens are available year-round but their peak season is from January to April.
Storing: Collard green should be stored in an airtight plastic bag or container and placed in the refrigerator for up to five days.
Enjoying:
- To get the most health benefits from collard greens, spray lemon juice over leaves and let it sit for a minimum of five minutes before cooking. This will activate the myrosinase enzymes and increase formation of isothiocyanates present in the greens.
- For maximum nutrition and flavor, steam collards for five minutes. They can be tossed with light dressing and eaten as a side dish or salad.
Resources & recipes:
Tropical black bean and collard green soup: http://blog.fatfreevegan.com/2010/01/tropical-black-bean-and-collard-green.html
Southern-style collard greens: http://herbivoracious.com/2009/10/southernstyle-collard-greens-veganized-recipe.html
Collard wraps: http://avocadopesto.com/2012/04/10/raw-vegan-collard-wraps/
References:
Ambrosone CB, Tang L. Cruciferous vegetable intake and cancer prevention: role of nutrigenetics. Cancer Prev Res (Phila Pa). 2009 Apr;2(4):298-300. 2009.
Clarke JD, Dashwood RH, Ho E. Multi-targeted prevention of cancer by sulforaphane. Cancer Lett. 2008 Oct 8;269(2):291-304. 2008.
Cornelis MC, El-Sohemy A, Campos H. GSTT1 genotype modifies the association between cruciferous vegetable intake and the risk of myocardial infarction. Am J Clin Nutr. 2007 Sep;86(3):752-8. 2007.
Higdon JV, Delage B, Williams DE, et al. Cruciferous Vegetables and Human Cancer Risk: Epidemiologic Evidence and Mechanistic Basis. Pharmacol Res. 2007 March; 55(3): 224-236. 2007.
Jiang H, Shang X, Wu H, et al. Combination treatment with resveratrol and sulforaphane induces apoptosis in human U251 glioma cells. Neurochem Res. 2010 Jan;35(1):152-61. 2010.
Kahlon TS, Chiu MC, Chapman MH. Steam cooking significantly improves in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage. 2008 Jun;28(6):351-7. 2008.
Larsson SC, Andersson SO, Johansson JE, et al. Fruit and vegetable consumption and risk of bladder cancer: a prospective cohort study. Cancer Epidemiol Biomarkers Prev. 2008 Sep;17(9):2519-22. 2008.
Moore LE, Brennan P, Karami S, et al. Glutathione S-transferase polymorphisms, cruciferous vegetable intake and cancer risk in the Central and Eastern European Kidney Cancer Study. Carcinogenesis. 2007 Sep;28(9):1960-4. Epub 2007 Jul 7. 2007.
Rungapamestry V, Duncan AJ, Fuller Z et al. Effect of cooking brassica vegetables on the subsequent hydrolysis and metabolic fate of glucosinolates. Proc Nutr Soc. 2007 Feb;66(1):69-81. 2007.
Steinbrecher A, Linseisen J. Dietary Intake of Individual Glucosinolates in Participants of the EPIC-Heidelberg Cohort Study. Ann Nutr Metab 2009;54:87-96. 2009.
Tang L, Zirpoli GR, Jayaprakash V, et al. Cruciferous vegetable intake is inversely associated with lung cancer risk among smokers: a case-control study. BMC Cancer 2010, 10:162. 2010.
Zhang Y. Allyl isothiocyanate as a cancer chemopreventive phytochemical. Mol Nutr Food Res. 2010 Jan;54(1):127-35. 2010
http://www.whfoods.com/genpage.php?tname=foodspice&dbid=138
http://www.seriouseats.com/2010/03/in-season-collard-greens-choosing-storing-recipes-20100320.html
